Help, serious BOG from 3k to 5k on cold KA24DE?

[MELLO*SOS]

** SOLVED - Read through to find the solution (replacing KS with resistor) **

Hi all,

I have noticed this problem with my car (92 KA24DE) since the day I bought it... When the engine is cold, it will usually bog very heavily on WOT after shifting into second. It's noticeable enough that it throw you forward in the seat. I've dealt with it, but now it's just out of control...

For the last few days it's been overcast and cool (60s) in the mornings here. When I leave to drive to work, the engine DOES NOT want to rev on WOT between 3000 and 5000 RPM while driving! Sitting in nuetral the engine takes forever to rev and noticeably slows down between 3k and 5k. Everything on the car is stock, and since this only seems to happen when the engine is cold I think it might be a sensor loose or malfunctioning... It seems to go away after driving the car for 15-20 minutes; my commute to work is all city streets and only takes about 10-15 minutes.

The bog-after-shift-into-second will happen when I leave from work each day, but only seems to happen once.

If anyone has experienced this or has any suggestions, please let me know. I have replaced the plugs and fuel filter very recently (as soon as I got the car actually), so it's not either of those......

edit: it doesn't matter the temperature, hot or cold it still does this
edit: the problem is solved. Scroll down for the solution :Owned:

[Var]

Blindly guessing i'd say try changing the TPS first.

[MELLO*SOS]

My first guesses (well after fuel filter and plugs) were TPS and fuel pump and/or regulator. I wanted to post on here first hoping someone else has experienced this before I start replacing everything one sensor at a time :).

Thanks for your input :bow:

[sr240mike]

You could try measuring the voltage of the tps before replacing it. Grab a voltmeter and shove the prongs through the back of the sensor connector to make contact.

[MELLO*SOS]

Aw I forgot to ask in my last post about TPS testing techniques. I have a DMM, which wires should I measure and what should the voltage be at 0% and 100%?

Any other sensors or devices that could possibly be causing this? Moisture/condensation in the TPS could very well be the culprit; although it seems unlikely since it has this same problem whenever the engine is cold... Like when leaving from work (car baking outside in 95+ temps all day long). It only lasts for a brief moment, then it's gone for the rest of the drive....

[Var]

With 0% throttle the voltage should be .5 and at WOT(wide open throttle) it should be 4.5


The problem you're having shouldnt show up at these areas and you need a DSO to check it. A multimeter is only good for showing high and low, but not mid-range and it wont find electrical noise like a DSO will. I would just go ahead and test it with a multimeter like mike said, but if it check out ok, it still may be damaged. Swap it out with a junkyard one to save money

[MELLO*SOS]

Thanks for the info.

I don't think the DMM will show anything either; due to the fact that this problem "goes away", and if there really were a dead spot on the TPS, it should show up/be there 100% of the time...

Forgive me for asking, but what is DSO? Edit: doh, a digital storage oscilloscope. I would sure love one, but don't have the funds at the moment :(

I had a great obd2 setup for my 99 cougar for my laptop that let me see EVERYTHING going on in real time, plot graphs, etc... I really miss having a nice diagnostic tool like that for my 240. Is there a tool that will allow me to do something similar on the s13s?

I'm almost certain it's a bad sensor somewhere. If I could watch their outputs and compare that to "normal" ranges I would probably be able to figure it out instantly. Maybe something has a bad ground... It could be a million things at this point, and I don't have the time or money to get into a "replace one sensor at a time until it's fixed" state...

[idlafie]

Have you tried putting your ECU into Diagnostic Mode & see if the engine is throwing any DTC's, (diagnostic trouble codes)...????

Check the wire leading to your Engine Coolant Temperature Sensor, along with your Oxygen sensor. Also check to see if the EGR valve is working properly. Maybe sticking due to carbon buildup.
Cheap & easy fixes you might want to try are 1). Replace the air filter along with the distributor cap & rotor, (if you already haven't). 2) Check the spark plug wires with an ohm meter to make sure they are still in good shape...no shorts in the wires. Make sure they are firmly attached to the distributor cap & plugs. 3). Pour a bottle of fuel injector cleaner into the gas tank at your next fill up 4). Clean out the throttle body, EGR & IIAV AIV valve with a bottle of carburator cleaner. And 5), Check your ground wire that runs from your engine block right above the 02 sensor to your firewall. Make sure it's still connected.
See if any of the above help to improve or fix your bogging problem.
Hope this helps....
Good Luck!!
ID
'95 SE

[MELLO*SOS]

Hi

Thanks for the suggestions!

All the plugs and filters were replaced less than 3000 miles ago, but the cap & rotor and plug wires were not replaced. I am buying a new cap & rotor tonight, possibly a set of plug wires too.

When I was having this problem originally I thought it was either a fuel delivery problem (clogged lines, filter or injectors) or a timing problem (retarded due to bad sensor). I replaced the fuel filter and ran 2 bottles of injector cleaner through, with no positive results. I am wondering if I could have a faulty fuel pump, but I don't have a fuel pressure gauge yet. Regarding sensors, I contemplated TPS, ECT and MAFS (of course). None of these have been replaced yet though... I'll do the more simple/cheap stuff first (wires, cap, etc) and hope that solves it.

Can you please link me to a tek to get my ECU into diagnostic mode so I can read any stored DTCs? My check engine LED seems to be burnt out, as I've never seen it turn on (even during startup or a stall). I hope it doesn't require that LED (# flashes = DTC, etc) :)

[idlafie]

http://www.240sx.org/faq/index.html

Off the 240SX.Org website. Click on the FAQ button...the above link should already put you there though.

Once the page loads, look to the links on the left. Scroll down till you get to ECM...Reading Trouble Codes...DOHC

It should tell you how to put your ECU into Diagnostic Mode. If you still have any questions, then download a S13 FSM from here....
http://www.ffdet.com/members/rich/Nissan/nissan.htm
It will be the links on your right side...S13 KA24DE Manual....click & download.

All this info should get you going in the right direction. Hopefully it will help you solve your Bogging problem...

Anyhow...hope all this helps....Good luck!!!
ID
'95 SE

[MELLO*SOS]

Wow thanks for that link; somehow (?!) that got past me... I'll definitely put that to use tomorrow and find out what the ECU has to say. I have a feeling the check engine led is burnt out, so it's great that the ECU has it's own led...

Are there any serial or USB devices for our ECU?

Bump.. Anyone?

[MELLO*SOS]

Alright..

I still haven't pulled the codes, and the problem has got much more consistent. Every single morning it will have this feeling like it's only putting out 75% power on WOT only. I am starting to think the problem might be with condensation inside something, because it does this every morning until something heats up and/or dries out. Anyways, it will also do this sometimes when the engine is cool (sitting for a whIle).

I replaced the distributor cap and rotor this morning before work. I was (almost) certain that it would solve the problem, because I examined the cap when I installed the efans and both the cap and rotor were showing signs of wear. I cleaned them up as good as I could but knew they should be replaced... Anyway I replaced em both today, but sadly the problem is STILL there. I guess the good news is that now when the problem "goes away" the car pulls harder on the top end due to the new cap&rotor.

I am going to pull the codes and/or replace the plug wires next. Then most likely TPS, unless the codes tell me something useful (which I have a feeling they wont).

[Flybert]

WOT on a cold engine? Anyone else see a problem with this?

[MELLO*SOS]

Once my '88 ranger (2.9L V6) had a very similar bug... But it wasn't just on cold engine, it was WOT in general. I popped the hood and revved the motor, heard a clicking/arcing and saw that one of the plug wire boots was arcing to the exhaust manifold. Only at WOT did it have enough spark power to jump the gap, otherwise the engine ran fine.

My plugwires LOOK okay but who knows... I haven't replaced them since I bought the car, so who knows when they were last replaced. Those are next on the list ;)

TIA

[MELLO*SOS]

WOT on a cold engine? Anyone else see a problem with this?

Let me clarify...

By "cold" I mean 5-10 minutes after the engine has been started and warmed up to normal operating temps. Go get in your car in the morning, fire it up and drive around your block a few times until your temp gauge is reading normal. Now go WOT in whatever gear you want -- you have power right? Well my car doesn't, it feels like it's only firing on 3 cylinders OR there is something retarding timing (or something else is fucked). It's scary when you're trying to merge into traffic and the car is falling on it's face instead of pulling with normal power. I shouldn't have to drive a car for 15-20 minutes before it operates correctly; the car didn't USE to work like that and my KA24DE powered Altima has no problems whatsoever like this.

If you don't have anything constructive to add, please don't post. I don't need that kind of shit in my thread, it doesn't help me solve my problems any quicker. :mrmeph:

[MELLO*SOS]

Well I just got the car back from my mechanic, he too doesn't know what's going on. His best guess is a clogged cat. Go figure....

I'll buy a high flow from ebay and try that out. I hope it solves the problem. What fun is a car with coilovers, sways and powerbrace when it has no power :(

[idlafie]

From the folllowing website:
http://mysite.verizon.net/res0pda6/id40.html
Sometimes you can tell that a converter is clogged because you don't go any faster when you push the gas pedal. Also, there usually is a noticeable drop in gas mileage associated with a clogged catalytic converter. A partially clogged converter often acts like an engine governor, limiting the actual RPMs to a fast idle. A totally clogged converter causes the engine to quit after a few minutes because of all the increased exhaust back pressure.

Often, the only way to tell if a catalytic converter is malfunctioning (plugged) is to remove it and check the change in engine performance. When a clogged converter is suspected, some mechanics temporarily remove the O2 sensor from the exhaust pipe ahead of the catalytic converter and look for a change in performance.

Try that out & see if it works...

Another way to test to see if your cat is clogged, install a vacuum gauge at a port that has full vacuum, (at the carbon cannister or the throttle body..you'll have to check the FSM for the right spot). Fully warm up the motor; the reading at idle should be 18 - 20 InHg. Run the Rs up to 4,000; it should be at least 21 InHg. If the reading plummets way under 18 InHg, then there is a major exhaust restriction. I'm surprised your mechanic didn't do this...???

Anyhow, hope this helps....
ID

[idlafie]

Let me clarify...

I shouldn't have to drive a car for 15-20 minutes before it operates correctly; the car didn't USE to work like that and my KA24DE powered Altima has no problems whatsoever like this.



D'OH!!!!.....forget my last post about the cat....if your car runs fine after 15-20 minutes of warming up, then it's NOT gonna be your cat that's causing a problem. If it WAS your cat that was bad, then your car would be running like crap ALL the time..and not when it's just cold.

It sounds like one of your soleniod valves is stuck open when it shouldn't be, allowing too much air back into the intake manifold past the MAF causing your car to bog. Only thing I can suggest is for you to crack open the FSM you downloaded, (I hope you did..see previous post), and check out the PCV valve, IACV system, & the EGR system. You're gonna have to follow the diagnostic procedures written in the FSM to track down your problem.

Just out of stupid curiosity, did you check your ECU for any Diagnostic Trouble Codes?? Did it kick any? If so, what were they??....If you haven't, then I suggest you do...you WON"T be able to figure out what your problem is till you do....

ID
:rant2:

[Dream240]

Okay, couple things, this is manual right? Then how about the clutch being bad? Or maybe there's a problem with the throttle body getting stuck? I know the problem goes away, but maybe that's just cause of the warm up. I know in my bro's integra he had a bog problem and when he replaced the engine and installed a new clutch and flywheel the old clutch came out in pieces (totally fubared). Just a suggestion.

Also if that's not it then what about the engine codes? That's a for sure check...I know it was already mentioned but I'm just emphasizing (spell it right?)

[MELLO*SOS]

Okay, thank you guys for the replies :) I am determined to keep working on this and posting until it's solved. Even if it means ripping this ka out dropping something else in :P

BTW the problem has got worse, now it doesn't even matter what temperature it is or how long you've been driving. Sometimes there is power, sometimes not... It really sucks, I mean our cars should be able to do a wicked burnout when it's wet outside, and when this problem is present the GD thing doesn't even have enough power to break the back loose on a wet corner :cry:

So, following my mechanics advice I picked up a high flow cat from PDM... It should be here next week sometime so next weekend you guys should see a post from me again. I'm not certain that it will solve the problem, actually I'm betting it's probably not but this is a good excuse to install upgrades on the car :)

I don't think it's clutch or throttle body. Clutch should mean that the engine revs clean but the power never makes it to the wheels... Throttle body, what could go wrong there, except bad TPS or something? I think it *COULD* be TPS..... But as said above, if cat doesn't fix it then I'm going to examine IAV.

I have yet to pull the codes :P I know I'm lazy... That will probably give more insight if the cat doesn't solve the problem. I really don't want to put much time or money into this engine, as I'm hoping to get it swapped out in the next 3-4 months. Right now I'm upgrading suspension, then brakes/wheels and trying to save for an engine swap, so I'm hesitant to spend much money on parts that won't transfer over after the swap.

[Dream240]

I don't think it's clutch or throttle body. Clutch should mean that the engine revs clean but the power never makes it to the wheels... Throttle body, what could go wrong there, except bad TPS or something? I think it *COULD* be TPS..... But as said above, if cat doesn't fix it then I'm going to examine IAV.

Well, the throttle body could be sticking....just alot of carbon build up in there causing it to stick when trying WOT thus producing that lagging feeling. I've had this problem before with my old Accord. Just grab some throttle body cleaner and spray it down pretty good. Car should be off. make sure to open the throttle manually with your hand and spray some in there good. check to see if it's all black inside (probably is). Also spray the outside of the throttle body, get the whole area nice and wet, :) Let it settle for about a min. then start up the car (put the intake back on first). let it run the cleaner through for about 30 seconds, then shut it off, and repeat. Maybe 3 or four times. Then take the car out and see if it helped. Worth a try considering a can of cleaner costs 2.50 at autozone. Try it and see if that helps.

[nissandr1ft]

My car acted like that sort of, not just when cold. It was my MAFS, just cleaned the wires with carb spray.

[MELLO*SOS]

A buddy suggested MAF too, looks like a can of carb cleaner will do both the TB and the MAFS. Thank you guys for all these suggestions! I'm sure it's ONE of the things above, now it's just figuring out which :/

[MELLO*SOS]

Alright, this past weekend I installed a brand spankin new cat from PDM racing, only to find out -- guess what -- it's not the problem. I sort of knew that it wouldn't fix the problem, because the "OEM" cat looked clean inside & I was able to look through the honeycomb...

So now I'm trying to buy a MAF off a fellow zilvian, with hopes that it solves the problem. I'm still lazy & haven't pulled the codes.

[Dream240]

okay WTF...? Now I've got a bog. But it's only when I go to take off from a dead stop and only when I give it a little gas. I can't feel it when I push on the throttle normally or hard. i already cleaned out the throttle body with cleaner and added a can of Lucas fuel cleaner to my last fill up. No luck. before all this I installed my new high flow cat, which BTW didn't solve the problem either. I've got to fix a small leak in the cat-header bolt up but I'm sure that's not it. Next is the spark plugs and fuel filter, which aren't really that old. Maybe 60k miles...? hmm....

so now i'm jacking your thread :)

[idlafie]

okay WTF...? Now I've got a bog. But it's only when I go to take off from a dead stop and only when I give it a little gas.
.....Next is the spark plugs and fuel filter, which aren't really that old. Maybe 60k miles...? hmm....

so now i'm jacking your thread :)

Hey!!!...no jacking threads...start your own!!! :rant2: :rant2:

Hahaha...all kidding aside....check your throttle cables....they might have stretched & be slightly out of adjustment. If that doesn't do it, then check your ECU for codes. If none pop up, try cleaning out your PCV & EGR valves. Changing plugs & fuel filter should definitely help though....just make sure to run NGK plugs....I've heard too many people complain about other types of plugs.
Anyhow, hope this helps....
ID

[Dream240]

Yeah NGK iridiums are what I run. Throttle cable hmmm? didn't think of that. I'll check it this weekend. And the EGR and PCV maybe get to that too....got alot of stuff to do this weekend. Swap doors :) swap out brake hard lines and MC resevior, change out front pillow mounts, find suqeaking in rear shock assembly, whew....!!!!

Thanks for the tips.

[stinky_180]

how would you go about cleaning the EGR valve?

[ledzeppelin240]

Fully warm up the motor; the reading at idle should be 18 - 20 InHg. Run the Rs up to 4,000; it should be at least 21 InHg.

The vacuume should decrease the more the throttle plate is opened. This is due to less restriction. This is why diesels engines have a vacuum pump, due to there is no restrictions to create vacuum.

[eliterit]

i had horrible bogging when i swapped to a dohc motor.

what i did was i checked the ecu for codes

and it was throwing a code for a bad knock sensor

took my knock sensor out and it was badly cracked

that fixed it


try checking for codes

[Dream240]

i had horrible bogging when i swapped to a dohc motor.

what i did was i checked the ecu for codes

and it was throwing a code for a bad knock sensor

took my knock sensor out and it was badly cracked

that fixed it


try checking for codes

Okay here's what I got from my brother, a mechanic, he says that on OBD-II cars (some 95's & 96' and up) you WILL NOT have a code problem unless the engine light comes on. Now for OBD-I cars, the CEL may not come on and you could have codes running around in there. Since my car is a 96' and I have no CEL then I'm sure there's no codes floating around in there. He syas that all OBD-II cars run constant diagnositcs while driving and any permanent change in the cars performance will be noted. If it's an intermittent problem it won't throw a code until it permanently breaks. Sounds weird but makes sense. I'm sure it's mechanical, like the throttle cable or clogged EGR, something like that. I still have yet to check this problem. Should be able to get to it this weekend.

[eliterit]

i understand that , since your car is a 96, but i was talking to the guy who has the 92 motor, mello88

[MELLO*SOS]

Alright

I bought a MAF off a fellow Zilvian who assured me it was running when pulled. I threw the MAF on last night only to find that my car would barely start then sputter and die. I reinstalled my MAF and the car fires up and idles properly.... Also measured my MAF signal at idle it's around 1.02v or so... 2000 rpm it's closer to 2.0 volts...

So I don't think my MAF is the problem. I am getting desperate here, I just might pull the ECU and check codes tonight...

Maybe some of you threadjackers have some more ideas or want to buy a busted MAF?

[idlafie]

Okay, couple things, this is manual right?

Yeo Mello.....just wanna clarify something here. Did you ever respond to Dream's question about your car being a Manual Transmission or Automatic Transmission. Did you ever post in your thread if your car was a Manual or Auto tranny? I don't remember seeing it....

And as for pulling the DTC's....see what pops up & let us know.

ID

[MELLO*SOS]

Sorry I musta missed that one, but yeah the car is a manual.

The guy I bought the MAFS from assures me it was pulled from a working car with none of the symptoms in my last post (sputtering, etc). WTF... Also found out it came from a '91 with a KA24DE.. On the sticker on the MAF there is a 5 digit (iirc) code that is stamped, is that the calibration code? Those numbers don't match between my MAFS, but the part numbers on top are identical.

Thanks

[idlafie]

The 91 MAF should work...

Nissan lists only 3 MAFS for the KA

89-90 KA24E
Part #22680-40F00
(also found on 1990-91 Nissan Axxess & 1990-92 Nissan Stanza)

91-94 KA24DE
Part #22680-53F01

95-98 KA24DE
Part #22680-70F00

So have you checked your ECU for the DTC's yet??

ID

[MELLO*SOS]

Yeah I have the 22680 53F01, the #s match on both MAFs

Tonight I pulled the codes and found out it's got a 12 (MAF and/or harness) and 34 (knock sensor). I did some searching and found that for 12s it's common to have bad grounds, so I'm going back to to inspect & check resistances. I also read that the same bad ground can cause the 34...

How to test the MAF w/ dmm? What pins are what?

[MELLO*SOS]

Damn it I just went out and inspected things... The MAF wiring looks perfect and all the factory grounds are in good condition. I tested with my DMM and things seem to be grounded, but I have a few questions.

First off how do I check the MAF's groundedness? Even while the harness is connected the MAF will not ground to the block. I took off the plug and tested the right two pins and they measured 1440 ohms between themselves or to ground. Is this normal and if not where else should I measure from to find the bad connection point?

I will say that the way the car drives makes me believe that it could have a bad connection, as sometimes the car will just run fine but the majority of the time it doesn't. A bad connection could definitely be causing this, but everything I've inspected so far seems to be in order.

What is my next step? Should I test the connection for each wire from the MAF plug back to the ECU harness? :goyou:

[idlafie]

Yep...test the wiring from the MAF back to the ECU AND to the ground.
http://www.emergent.com.au/200sx/s14-ecu.html

Also check the ground in your wiring harness...
http://www.alldata.com/service_provider/techrx/2000/20000713.html
I know...I know...the above link doesn't exactly talk about KA24DE engines, but if Nissan screwed up the harness on the truck KA24E harnesses, what makes you think they DIDN"T on the KA24DE harness?? Recheck all the wiring crimps AND connections/connectors on your harness. The torquing motion from your weak motor mounts could have caused the harness wires to go bad.

Also, you might want to cut & resolder a new ground grommet where the harness wires connect to the engine block. It's the stack of wires that connect to the engine block directly above the oxygen sensor & next to the brake booster towards the back of the engine block on the driver side. You'll spot the wires once you pop your hood & look.

Anyhow, hope this helps.
ID

[MELLO*SOS]

So Another round of testing done with no luck...

1) Codes
I cleared the codes (only code 34/knock since last clearing)

2) MAF

Installed the other test MAF again. The car did the same thing where it idles for about 1-2 seconds at 1000 then drops to 400 then back to 800,200,600,etc and dies. I checked the codes & was surprised not to see anything... I measured the signal out of the MAF and at "idle" it's showing about .8v (the FSM suggests .8 to 1.2 is normal). After the car dies or when the revs dip too much the signal drops to .3 or lower, so it looks like it's giving a good signal? But I tried many times to start the car and it just *isn't* going to work with that MAF for whatever reason.

I reinstalled my old MAF and the car would start fine. For my own information I measured the signal from my MAF and saw a happy 1.02v at idle, rising to about 2v near 3000rpm. I unplugged the MAF and the car runs in limp mode and won't rev past 2500 rpm. I seem to have a working MAF...

3) MAF grounding

I also tested the harness going from the MAF plug to chassis ground and found that no matter what I touched or wiggled it had a good .06ohm resistance, so it doesn't seem to be an issue with grounding. This is testing from the ground pin on the harness plug to a bolt in the core support that my efans ground to. As far as I can tell it is a good ground connection (visual + dmm). Didn't test power or signal wires, but did see that the MAF gets ~12v at engine on.

4) TPS testing

Tested the TPS per the FSM, measuring k-ohms at closed throttle I get 1k and at WOT I get 8k. The FSM suggests that the range is normally 2k to 10k, but I don't know what the acceptable deviance is (I would imagine +/- 1KO is fine tho).

I slowly rotated the throttle plate from 0% open to 100%/WOT and found that the resistance climbs linearly, no flat or dead spots. Many closed->WOT->closed cycles tell me that it goes no higher than 8kohms and no lower than 1kO.... I don't think the TPS is the problem either. The car doesn't run very well at all if you unplug it.

5) Engine ground near O2 sensor
I checked the ground location above the O2 sensor on the block and it seems to be in good condition. I tested resistance from the distributor to the grounding bolt on the firewall (above the o2 sensor) and it showed very little (if any). I tried wiggling the ground strap and that didn't produce any changes either. Unhooking the ground strap didn't make any difference either, so obviously there is another ground somewhere that is working. I also measured continuity between the ground strap bolt on the block (above o2) to the bolt on the firewall and found that the connection is good.

6) Battery ground
Also visual inspected the battery ground leading to the intake manifold bolt. The wire looks in good condition with solid connections. All bolts were tight and no signs of wear or corrosion.

7) Battery terminals
I removed both terminal clamps and cleaned both terminals and both clamps. I also unhooked the unused wire that someone ran for an amp in the trunk. I inspected the terminal clamp crimps and they look good, no corrosion. I reinstalled both leads to the battery...

8) canister purge
I almost forgot that I checked this too, per the FSM for 'hesitation while hot' diagnostics. They suggest that you disconnect the 'purge' vac line going to the canister. I did that, pluged the hose and the canister and took the car out for a spin. It still drives like shit, nothing I have done today has fixed anything. If anything, it has shown me that I have many functional parts on my car with a good amount of life left in them. I also have seem to have a drift gremlin :fruit:, hiding, taunting me :mephfawk: from the bowels of my engine bay :ugh:.

Since that pesky #34 code keeps coming back I think I should inspect the knock sensor next... I have just been assuming that a problem with the MAF or wiring could cause a knock due to bad input data and thus legitimately fire the knock sensor. The FSM was particularly vauge on the knock sensor :(. It didn't give any creative insight as far as testing methods or signal output. Can I just unhook the knock sensor to test? I've seen a few other code34/knock threads so I'm searching on this now...

Other facts about car:
Here are some additional electical-system facts about the car that I have learned of that may or may not be related. The car had an alarm installed when I got it, and I've found a power wire ran to the trunk for an amp for a stereo; so someone has obviously spliced into certain things, what or how professionally I don't know... The car has some funky things it does, like randomly lighting the seat belt lamp and dinging the chime. The passenger seat belt auto motor is broke and we never use lap belts in the car. Sometimes only the chime will go off, just while you're driving down the road. (like a door is ajar, but the doors are closed). Also, when you first get in the car and turn it on there are a bunch of clicks that come from whatever relay lives in the center console. I mean like 15 to 20 clicks, maybe that's a suggestion that a relay is going out (or a bad wire leading to it?). I don't think this is normal, but can someone else confirm if their car makes similar noises when turning on the key (I notice it in the morning, but I don't know if it has anything to do with being cold). I notice that these clicks will sometimes happen in conjunction with the chime going off, which suggests to me a wiring problem there.

Thanks again for any input you have :cool:

[MELLO*SOS]

Okay after reading more in FSM I am going to check knock sensor from ECU (pin #27) to the ks sub-harness first then check from sub harness to ks. KS seems to have only 1 wire going to it from the ECU... Also might pick up a resistor from frys to bypass as a check..

edit: Just finished more testing

1) Per FSM Unhooked knock subharness connector, small plug at front pass side corner of valve cover near TPS plug. It has 2 wires, one white one black. White runs back to ECU, black goes to ground. When the KS is connected the white wire runs to the KS and it grounds itself (the black wire) into the block. Unhooked ECU harness from ECU. Checked resistance of black wire to ground, it's continuous. Weird thing is that I checked the white wire and it also ground. In fact if you connect the two together they form a circuit? This whole time the ECU harness was unhooked from the ECU, as if somewhere the white wire is shorted.

2) Started & drove car without KS hooked up, still drives like shit. Went to radio shack and bought some 1megaohm resistors. Installed one right there in the parking lot (just jumped the subharness connector pins with one, but it made no difference in performance. Came home + took out resistor jumper + reconnected to KS. Cleared ECU codes (12 and 34 were present, 12 because I unhooked the MAF while engine was on).

I am starting to think that the white wire is shorted somewhere between the ECU harness and the knock sensor subharness.

When I measured resistance I saw 200kohm with key off and 300kohm with key on. When the engine is running there is about 2 volts present on pin #27..

:axe:

[MELLO*SOS]

So today when I started working on the car I pretty much knew that the wiring going from the ECU to the knock sensor had a short somewhere. Instead of tracking it down, I tried a simple fix of bypassing the knock sensor by splicing in a 1 megaohm resistor between ecu pin #27 and ground. I did this, then cleared the codes and went for a drive.

Right away I noticed that the bog is entirely gone, I couldn't make the car drive like it has been (bog) no matter what I did. I drove for a while until after the car was warmed up so I'm pretty sure it's gone. Over the next week or so I'll monitor the situation, but for now it has been fixed.

So if you're getting a code #34 here is what I suggest you do:

1) Take out your ECU and test pin #27 (top row, from the right of the bolt there will be a blank in slot #4 then top #5 is pin #27) to subharness pin (white wire). The subharness connector is right there above the water pump near the TPS connector, it is a small black squareish connector with 2 pins inside. It goes right to the knock sensor. Unhook the connector and test resistance between white wire and #27 on ECU harness, it should be 0.

Either the problem is a bad knock sensor, or bad ECU->subharness wiring or bad subharness->knocksensor wiring.

For a quick fix, a 1 megaohm resistor will work well as a dummy knock sensor. I don't suggest this if your car has anything done to it that would promote detonation, as the ECU will no longer be able to pull the timing.

Thanks everyone for the help

[idlafie]

Okay...dont' want to raise a post from the dead....BUT....
I give you credit for the additional troubleshooting that you did & the ensuing writeup....you did a lot of good work....glad to see that it paid off...
If you go to the Shine Street meet, you can point out what you did..
ID

[MELLO*SOS]

Hey thanks for the comments, I just hope it helps someone else solve their problem cause I'm sure this'll come up again...

Is Shine Street the oxnard meet? I'll be there next weekend.......

[CHARLIE2020]

Ok im also throwing a code 34 (knock sensor) i've also tried swaping knock sensors but I still get the code 34 even just as lil as 5 seconds of running after clearing codes and changing knock sensor.

I swaped my original knock sensor which by the way was cracked I also measured resistance accross the cracked knock sesnor which was 560Mega ohms, I also measured against a new used knock sesnor shich also read 560Mega ohms, only difference was when I submerged the cracked knock sesnor in water being carefukl not to get the terminals wet which would bridge the connection the cracked knock sensor resistance would jump all around whereas the new used not cracked knock sensor stood steady at 560k ohms.

I have also check the resistance in the white wire from ECU to subharness and I get 3 ohms of resistance and between ground and the black wire I get 6 ohms resistance.

If anyone has a known good knock sensor could you measure the resistance accross the knock sesnor and tell me what you gte or if the FSM says what it should be it would be appreciated, thanks.

[SlowCoupe]

what about timing?

[CHARLIE2020]

My timing is at 19 degrees.


For clarification:

All this is done with the ECU still connected to the harness, and is tested at the male end before being connecte to the knock sensor sub harness.

With ignition ON:
White wire gets 31.2 ohms resistance steady.
Black wire gets 16 ohms resistance steady.

With ignition off:
White wire gets 2.1 ohms steady.
Black wire gets .3 ohms steady.


Below is done with the ECU disconnected from the harness:

White wire gets 3 ohms resistance.
Black wire gets 6 ohms resistance.

[twitchy]

ressurrection again....

-if the wire was bad, would you just run your own between the sensor and the ecu to fix it?

-what is a knock sensor worth new?

-You all mention it being "cracked" can you see the crack in it just by looking or do you have to take it off....cause i seem to recall it not being very accessible

[OdessaS13]

yeah my shit bogs wen cold too same scenario.
new knock sensor is like around $100 maybe less
can anyone confirm if you can indeed run your own wire from pin 27 to KS.

[MELLO*SOS]

yeah my shit bogs wen cold too same scenario.
new knock sensor is like around $100 maybe less
can anyone confirm if you can indeed run your own wire from pin 27 to KS.

That's it. I found it much simpler to run a wire from p27 to 1mohm resistor to ground as a bypass.. If you do that and it fixes your problem then you can worry about running a new wire to the KS (or just drive around KS-less like I am, but not a good idea if you're turbo'd).

It's probably a pain in the ass to run a new wire, because the stock wiring goes from ECU to a subharness connector near TB to another subharness that goes to the KS.

GL

[CHARLIE2020]

Well I fixed my knock sensor error code problem.

After spending many hours actually days on this shit I finally fixed the problem and the ECU now gives me a code 55 :)......

Heres are the diagnosis steps I performed:

1. Disconnect ECM harness connector from ECM.
2. Disconnect KS subharness connector from KS.
3. Check harness continuity between terminal (B) and ECM terminal (27).

Im my case continuity did exist (so good to go right? NOPE) im still getting a code 34 and my knock sesnor is good to go.

Next I pluged everything back together like it should be then:

Step:
1) With a DMM, one probe to ground other back probing pin 27 (Knock Sensor) with KOER and KOEO.

Results = 0.013v (no good) FSM states you should see aprox. 2.5v at idle and or KOEO.

2) I disconnect ECM harness connector from ECM and de-pin, pin 27 from harness connector alltogether.
3) I re-attach the ECM harness connector to the ECM with pin 27 detached from connector.
4) With my DMM I ground one probe and the other to pin 27 and I get 5v, so the ECU is good to go.

So next step:
1) Taking a jumper wire to pin 27 and reconnecting the original (white) KS wire to the jumper wire I instantly lose the 5v (so im thinking why what is causing this to happen (a short to ground etc etc)
2) I take the same jumper wire and disconnect the original (white) KS wire from it and get about 3ft of regular 16 gauge wire and run it directly to the knock sensor subharness terminal (B).
3) I take measurements back at the ECM with my DMM one probe to ground other to pin 27 and I get 2.5v (good to go finally:)
4) So now I clear the codes and start the car run it for a few seconds and shut it off.
5) Check codes for any errors and all is good (code 55 :) finally)

If some of you are wondering why I didn't get 5volts when I rewired, its becasue the KS itself is a 0.560M-Ohm resistor and it reduces the voltage down to approx. ~2.5v.

My code 34 was instantanious means I could clear the codes and get code 55, start the car for 1 second then turn it off and check teh codes and I have a code 34, thats becasue it basically had no voltage present of pin 27.

Some other things that still stump me is I still got continuity between pin 27 and the KS sub harness but why or where was the voltage going to im by no means an electrical expert but I wanna know where it was going, is that what a short to ground would do???

[MELLO*SOS]

Thanks for the replies and PM's on this thread, guys. In the interest of posting solutions to 3000-5000rpm bog I have another "solution" to this 3k-5k bog issue.

My car has recently felt like it has lost a good deal of power from the mid range through the top end under high load (3000 to 5000+, again!). I shrugged this off and thought it was related to the misfire-at-idle problem I have. But last night on a whim I installed my Walboro 255lph fuel pump, and WHAT A DIFFERENCE IT MAKES! The stock pump must have been getting tired and just couldn't keep up. With the Walboro installed the car feels 100x better, pulling much harder from 3000ish all the way through 5000. BTW the only performance related upgrades to my KA24DE at this point are: underdrive pulley, 110a alternator, poly motor mounts, 3" exhaust, efan conversion, nismo thermostat.

Just one more thing to check out if you're reading this thread because you have acceleration problems from 3000+ rpm. I am really impressed with how the engine runs now with the new pump, it's kind of scary to think that the old pump was holding it back that much.

Edit 4/6/2007: Still running on the KS bypass and Walbro pump, and the KA feels great. Well about as great as an NA KA can feel :) Although I believe the Walbro is overrunning the stock FPR and causing the car to run a little rich. If you spring for a Walbro pump upgrade, I would suggest picking up a Nismo FPR at the same time. Adjust the FPR with the vac line unhooked until your fuel pressure reads 43.5 psi (3 bar). When you hook up the vaccum you should see rail pressure drop to about 36-38ish.

[junkey311]

-----------------

[fulmore240]

bump..............

[MELLO*SOS]

Why the bump? Did this thread help you solve a code 34?

[Dream240]

Hey mello, with regards to your 06' post about upgrading the FPR.... did you ever do this?

I'm wondering cause I replaced my old pump with a Walbro but I'm still running a stock FPR. Do you think a failing stock FPR could casue a bogging issue? Doesn't sound logical but hey....with 240s the diagnostic sky's the limit...right????

[MELLO*SOS]

Hey Dream240, I don't think you'd consider it a bogging sensation, but you will be definitely loosing some power due to running rich. A quick cheap thing to do is buy a fuel pressure gauge and a tee from Jegs, splice that bitch in between the fuel filter and the fuel rail... You should be seeing around 36psi at idle WITH the FPR vac hooked up. If you unhook the FPR vac hose, it should be at 43.5psi at idle (AKA 3 bar). My fuel pressure with the walbro and stock FPR is way out of whack, above 40 psi with the vac hooked up.

Got any codes man?

[Dream240]

Well when this whole bogging problem started I was getting 11 and 21 codes respectively. According to the FSM I proceeded to inspect the dist. sensors, coil and power transistor. Since I was getting wierd readings from both the dist and coil, I replaced both, reset the ECU, and problem still persists. I haven't pulled any codes again since replacing the MAF (the last component I tried). Gonna check the injectors and fuel pressure tonight and pull codes again.

The Nismo FPR was definitely an upgrade I considered with the Walbro but the price tag just kicks me in the nuts!!!

Thanks.

[Saucy240]

[quote=The Nismo FPR was definitely an upgrade I considered with the Walbro but the price tag just kicks me in the nuts!!!

Thanks.[/quote]


The Nismo FPR totally made a difference in my car too ! :2f2f:

[Dream240]

Hey, did you guys buy the adapter bracket that is recommended? Is it necessary with the KADE? It says that it's needed on some vehicles where you will have access issues. And if you did need it, is there any other part that is needed? I'm asking cause if I do pull the trigger on it I want to be able to put it in with little down time. I hate it when I buy something only to find that I'm missing a bolt, gasket, etc.

Thanks!!

[MELLO*SOS]

I think there are two nismo FPRs for the KA, like a type A and a type B... I bought the one I needed for the RB and threw it on the RB in the garage. A while later I had to replace my fuel rail on the KA so I decided to install the FPR at the same time until I got the RB done. It turns out I got the "wrong" one [for the KA] because the adjustment nut hits on the head or the manifold or something. I ended up putting the stock FPR back on so I could reinstall the rail. I would probably go with the adapter and the universal FPR to be sure dude.

Also if you're still getting those codes after replacing the parts and resetting the ECU it's quite possible you have a short in the wiring somewhere. Try unplugging the ECU and measuring continuity on the related pins from the ECU harness connector to the actual sensor connector.

[Dream240]

Yeah I can only find the universal FPR for sale anyways. Cool thanks for the input. I'm gonna check the injectors, fuel pressure, and codes tonight. I'll let you guys know how it goes.

[jkeisser]

I had similar problems with this when my TB was bad.
As well when my O2 sensor was bad.

I didnt sift thru the 3 pgs, if you've already found the problem!

[Dream240]

Well I haven't found it precisely, gotta get home and work on it tonight. Got some good direction though.

We'll see!!!

[Dream240]

okay, I pulled the TPS out and rechecked it. Turns out it's wired correctly and working good.

I checked the resistance of each fuel injector and got the following:

#1 - 11.8 ohms
#2 - 11.8 ohms
#3 - 11.8 ohms
#4 - 16.3 ohms

I'm gonna get another used set of injectors and swap out the 4th one to see if the problem goes away. Thanks guys for all the help. I'll let you know if it gets fixed.