KA24DE power problem

[nissandr1ft]

To start off I've had 240's since about 98, and I know how my last ones have run. I've had this current 92 coupe since about December, and its been a piece of junk. The car was originally titled in Cali, so it has all the Cali emission options. The motor surges and stutters when I'm driving....below 4k it really lacks power, above 4k it starts building power, and 5500 on it runs like it should. Its like it comes in stages that are very noticeable. When your in neutral just revving it the cars stutters then catches and revs. Ive tried replacing nearly everything off a motor that runs well, or get it new. So far I've replaced the plugs, wires, cap, rotor button, fuel filter, and O2 sensor. Ive swapped over a different coil, distributer, coolent temp sensor, MAFS, fuel pump, and the ECU. The EGR is blocked, and the evaporative emissions is gone. The ECU I tried wasnt a Cali model, and they seem to run about the same. I've checked the codes with the cali ECU and it gave me a (14) speed sensor, (32) EGR, and (34) Detonation circuit. The EGR light was on with it connected and seems to run better lugged. The speed sensor is probably due to the digital dah only coming on randomly, because I checked it via the FSM procedure and it's fine. I've been wondering if its the knock sensor because that would make sense that the ECU is pulling timing and itd be runnin like this. I tried jumping the knock sensor plug to see if that helped or leave it unplugged. Anyone have any similer symptoms that theyve fixed? Any ideas on what to check.

Steven

[nissandr1ft]

I heard from a freind to try regrounding my MAFS. I did that tonight with 10guage wire without any luck.

[Nizmo240_22]

Check your ignition timing.

Second check your throttle positioning sensor.

[Maeda]

It could also be a huge vac leak.

Try and hook up a new maf while your poking around.

[nissandr1ft]

alright, checked the timing and threw a third mafs on. Ill spray some intake cleaner around the back and see if its got a leak. Ill also throw a TPS on today.

[nissandr1ft]

Just threw another fuel rail, and FPR on.....didnt help. But I found a leak in my fuel hose under my filter. Also checked for vacuum leaks, by spraying intake cleaner, but I didnt hear any change in the idle.

[nissandr1ft]

yup replaced the hoses and it still doesnt want to run right. From what I understand if the TPS wasnt working then itd be an all the time thing. This problem sort of gets bad and better sometimees.

[nissandr1ft]

Ive noticed that the power comes back a little on warm sunny days, and really lacks at night and cooler weather. My Digital dash doesnt work till the circuits in that warm up, but it comes on also on warm days. Itll run good even if the cluster hasnt come on yet though. I hear theres a certain board that has cold sauter joints in it that just need to be resautered for it to work right....anyone know which ones on that?

[Maeda]

If you figure out the cold solder problem let me know.

How was the timing?

[krustindumm]

Make sure your EGR isn't stuck, or remove the entire system.

Then go through the FSM check procedures on all major input sensors (MAFs, ECT, IAT, etc). Make sure you do checks from the ECM plug too, there's always a chance there is a bad wire sometimes.

[nissandr1ft]

The EGR vacuum line is plugged, and the exhaust mani is plugged. I havent had a chance to check the timing....no timing light. Theres a big Nissan BBQ here on Saturday so Ill prob see if one of my freinds will bring theres. Im thinking since its throwing a knock code I may have the timing a tooth advanced and its only letting the timing back up top. So Ill try to retard it a tooth tommorrow and see how that goes.

[nissandr1ft]

I put another igniter on last night, and a third coil. Also pulled the distributer and moved it back a tooth and forward. it's definatly the correct tooth, and set it back a tad advanced. The cars main problem now is that when you first try to drive it the car stutters and wants to stall for a few seconds then catches and goes.

[Nizmo240_22]

I put another igniter on last night, and a third coil. Also pulled the distributer and moved it back a tooth and forward. it's definatly the correct tooth, and set it back a tad advanced. The cars main problem now is that when you first try to drive it the car stutters and wants to stall for a few seconds then catches and goes.
:-/

What octane are you putting in it? If the ECU senses a knock it's going to do that.

[altitude]

Are you using NGK spark plugs?

[nissandr1ft]

NGK platinum plugs put in 2 days ago, and those were regular NGK plugs that were in for about a month. I only run 93 octane in the car.

[jdm_s14_zenki]

im having a similar p roblem in my SR, bump!

[nissandr1ft]

Anyone else have any ideas?

[bluuuurr]

IACV? take it apart and clean it..

10 minute job that fixed 2 weeks worth of headaches for me

[BigVinnie]

I haven't delt with code 34 so I really couldn't tell you.
I have delt with code 32 and code 14. What I can put together from all this is that you are burning SUPER RICH. Code 32 dealing with the EGR/BPT will throw the ecu into safe mode, the On Board Diagnostic automatically switches the fuel curve to run rich. This is so that what ever problem is occuring with the code wont allow for any early detonation. This happens pretty much when any of the smog emissions aren't functioning correctly.
Code 14 for the speed sensor will also make the KA run richer in higher RPM's so chances are the fuel richness is probably very excessive from 2000RPM till about 5800RPM. Speed sensor does a few things. It regulates fuel in 4th and 5th gear for fuel economy, it also works as the speed governor. I know this as fact since the JWT stage 1 tune is just removal of speed governor and literally a 5HP gain at the wheels( I have a copy of this tune and it sucks). More than likely the wire/sensor underneth the transmission is just disconnected. If not look around the ecu for a snipped wire.
As for code 34 I looked up the diagnostic proceedure in the FSM, it says nothing about a faulty detonation circuit, and there is nothing like that stated as part of the Nissan ECCS discription. Code 34 reads that it is simply a leaky injector.
That is a good explination as to why you have a sever loss in power, the fuel richness is literally choking your engine.

[nissandr1ft]

Well the car was originally an auto, and now its a 5sp....all the stuff is hooked up. The speed sensor reads when the cluster comes on just fine, and the code wont come on if the cluster is working. The code 34 has come on with both of the fuel rails Ive tried on the car. The EGR code has been going off since ive owned the car, and I deleted all of the EGR equipment. Is there a way to jump the EGR sensor to read that its working correctly, ior am I just screwed on that?

[BigVinnie]

Is there a way to jump the EGR sensor to read that its working correctly, ior am I just screwed on that?

The only way to not get a code 32 to prevent fuel richness is to get a non cali model ecu. Only about 1/3 of the nissan production 240sx's were non cali. I wouldn't be able to find the ecu numbers either. Well I could, but that is like 2 hours of my time. But I will send you in the right direction. www.hybridka.com/eccs

[nissandr1ft]

I have a non Cali ECU also, and it didnt seem to change anything. I've made sure the EGR wasnt leaking, and I sort of remote mounted a knock sensor. I had another plug and knock sensor so I plugged it up and taped it to the intake. Doesnt seem to run any better... would the lack of any knock make the ECU think its malfunctiong or is the intake causing a knock like sound. The main problem Ive noticed lately is that my car when first started and I back up. When I put it into first the car seems to want to stall and buck then start going. The power thing is stil happening, but the bucking and stalling problem seems to be the main concern now.

[nissandr1ft]

Alright new problems have shown up.....now the car idles HORRIBLY. Really bad popping and stumbling at idle. Also noticed with the idle screw closed it still idles right about 600 at times and 1100 at other times.

[BigVinnie]

Alright new problems have shown up.....now the car idles HORRIBLY. Really bad popping and stumbling at idle. Also noticed with the idle screw closed it still idles right about 600 at times and 1100 at other times.


Clean your IACV.

[nissandr1ft]

Well I cleaned the IACV, and it seemed to have fixed the fluxuating idle.....but the idle stioll has a constant popping. Ill try to get a sound clip and put it up soon. The car still has a serious stutter when revving until until the motor is directly in the middle of the temp guage.

[nissandr1ft]

Update:
I put in a manual TPS, New NGK plugs (gapped .040), new fuel pump sock, checked fuel tank for rust, and new positive battery cable. Ive realised that if I rev it a bit from about 2k-4.5k for about 30seconds the stutter is gone....sometimes longer. If the car is warmed up completely ideling the problem is still there, until the motor is revved a few times. Before its revved the idle is horrible, low, and popping. After it idles pretty good, about where its supposed to be.

[wiggerman]

You really should sit down and read up about problems before ya start swapping tons and tons of parts out

[nissandr1ft]

Its not a big probl;em swapping parts out, I have 2 parts cars sittin around with known good parts. I know 2 Nissan Techs that I know take a look at it, and plenty of enthusiast look at it. Everything that we can think of thatd be causing a problem has been swapped, or tested. My other motor is about ready to drop in.... so if nothing else Ill throw that in and see if its just something internal. My timing chain is making tons of noise at the moment, so regardless it will be going in soon.

[nissandr1ft]

Update:
I had my alternator checked and it was only reading 11 volts with my electric fan on at idle, so I threw a nissan quet 110 amp alternator in. Also had a grounding kit laying around, so I doubled up on all the factory grounds. It seems to idle fine now, but whenever I start driving it....it seems to almost cut off. When it does it I keep steady throttle, and it usually jumps back in after rolling about 20 feet. Its not dying just feels like its getting zero spark. The only thing I can think of is that my valve seals are going, because if it idles a while it smokes pretty bad, and its getting oil in the cylinder which is interupting my spark. Anyone have opinions on this. The next step since Ive replaced about everything I can think of, is drop my other motor in, which has all new gaskets, and timing chain. I was just hoping to have this problem solved before that. Heres the link on how to fix the HUD cluster.... http://multi-index.myonlinesite.com/240sx/240sx_speedo.htm , I just got mine in and it works like new.

[nissandr1ft]

Well my car is runnin pretty rough still....esp at startup. Ive rechecked pretty much everything easy so my only guess left is vacuum leak. Does anyone have a good diagram other than the FSM for vacuum lines on the back of the motor. I took the EGR stuff off, but Im thinkin I may have plugged the swirl control valve also. I also wondered about the pinhole in the bottom of the throttle body... I had to plug that on both ends to get the alternator in. There wasnt room for any lines under there with the quest alternator. All I can say is that with my car warm it has a real bad stumble at any RPM till Ive drivin the car quite a bit. When I first start it up, I have to stay in the car and watch the tach, otherwise sometimes itll die sometimes. Ive tried to adjust the idle air, and it doesnt seem to do much. With the TPS unplugged the car idles about 1200ish and 800ish with it plugged once the cars warm and runnin decent. When I pull out of the neighborhood in the mornings completely stops pulling like my key is off, then rolls about 10ft in gear and starts pulling again. I was thinkin bad MAFS on that, but Ive tried 3 in the last week, and moved my ground. Im gonna have to take it on a 5hr drive to TN next week, so Im hoping to get this resolved before then.

[nissandr1ft]

Well I redid my vacuum lines, and rechecked it over and over. The car seems to have a solid stutter that wont go away.... idles better though. All I have hooked up is a vacuum line coming from Im guessing IACV, going to a T...one that goes to the FPR, and the other to the swirl valve. I unplugged both the plugs behind the valve cover. Im gonna check the voltage from the knock sensor at idle, and check my TPS with an Ohm meter at work tommorrow. Is there a good way to clean the MAFS, I think I cleaned my last one with brake cleaner not spraying directly at the actual sensor. Also correct me if Im wrong... but the correct way to measure the TPS is with it unplugged with an Ohm meter. Between the 2 wires I should be getting about 5.0 at WOT, and a little more than 2 at half throttle. The car runs great the longer you stay full throttle, but stuttors between gears. So basically 3rd, 4th, and 5th are fine... its just short bursts of throttle, laying into it hard.

[nissandr1ft]

Alright well Ive readjusted the TPS to .49v at closed throttle and 4.2 at WOT, and removed the ground on the MAFS this morning. The car still has a stuttering problem, Ill check the continuity tonight hopefully. If I dont find any problems with that Ill be checking the voltage out of the knock sensor at idle, and pulling the IACV off and clean it. Any other places to look?

[nissandr1ft]

The problem is still there, and my car sits at an idle of about 1600. I couldnt get the idle down anymore with the idle screw completely shut. I figured Id check the MAFS, and knock sensor anyways. The knock sensor reads .45v @1600 RPMS, and the FSM says that it should be 2.5V. Im guessing since its way out of range thatd be my problem. The MAFS was reading 1.25v @ 1600. Since the FSM only gives an inaccurate bar graph for the MAFS, and only idle voltage for the knock sensor. Could anyone get a reading at 1600 just for comparison value?

[nissandr1ft]

I havent unhooked the IACV connector yet, but Im wondering if my vacuum routing is wrong. Right now its one line coming off the IACV to a T which splits to the swirl valve and FPR...the only stuff thats not capped off. I started to take the IACV off today till i found the one bolt thats a PITA. I figured Id try to spray some carb cleaner through the line that connects to the intake. Now my car idles at 2600 and slowly goes to 3500.

[240sx=fast]

it sounds like you got a serious leak in the intake mani somewere to me............1600rpm idle is alot,i would go over all the intake gaskets again,because that just sounds obvious to me.same exact thing was happening to my ka and it ended up being a intake mani gasket (the one between the mani and the head) hope you get this worked out man.good luck

[nissandr1ft]

Well the idle problem is better now, apparently while I was workin on it I yanked the O2 sensor plug apart. Now it idles between 1800 and 2200.... not great but better than before. Its as soon as it taps 2200 the idle drops to 1800, then back to 2200 and so on. While out there i checked for leaks by spraying carb cleaner all around the intake...didnt rev so I dont think its an intake leak.

[240sx=fast]

sure your maf is pluged up?lol just kidding,i am lost dude.it doesnt make any sence.

[nissandr1ft]

Well Im an idiot the idling problem is situated... the rubber boot on the cruise came loose holding the throttle open. Im almost positive on the knock sensor being the problem, I know at idle it should be 2.5v. I tried to check but couldnt get more than .45v plugged or unplugged on the white wire. Am I checking that correctly? To get the car to run halfway decently you have to run tons of timing to cancel out what the ECU takes. Doing that seems to have mixed results though. From about 4k on it pulls fine, but theres a good miss earlier in the band, and it seems to cut spark or something sometimes when you first start moving. Does this seem like what the ECU would do?

[nissandr1ft]

Ive been takin my motor that gong in my car apart the last few days and ran into some weird things. The motor came out of my stepmoms 93 hatch (original owner). When I bought the car from her IIRC the front cover said 1994 which I just assumed was due to it being a very late 93. Well I took the manifold off and it has no butterflys, and it has S13 cams. I found the motor number and its 590794W , is there a place to see if thats just what came in that or if what replaced under warrenty?

Steven

[Frenzy13]

You have similiar simptons to a friend of mine. he was running an auto ecu on a 5 speed setup. make sure that you have either the 5 speed ecu or that you have the lower harness wired properly (unhooked from certain places or something) or the auto ecu makes the car run really rich. Don't know the wiring set up though.