ka24de PROBLEM

[osal]

i ve bin fightin this wierd hesitation problem for months now...searched and searched forum after forum...common culprits checked out ok..

-maf sensor(tried another one)(cleaned it)(cheked wires, continuity)
-o2 sensor(replaced)
-coolant temp sensor(replaced)
-took apart intak manifold, cleaned egr, aiv, replaced pcv replaced all vaccumlines behind egr
-fuel filter replaced
-new plugs
-new wires
-cheked compression( pretty good actually 180 across all cylinders)
_cheked ecu codes( code 41 only, replaced intake air temp sensor) cel light went away after that
_replaced cat with a high flow one, even replaced entire exhaust since the old one had holes.
-replaced distributor
-timing at 20btdc
-FUEL PUMP replaced(walbro)
- added ground wires

CAR: 1995 240sx
ENGINE: ka24de(OBD2)


PROBLEM:...car idles hard as a rock no stumbling idle or anything, however wenever the car accelerates it does not rev smoothly,it revs kinda ok in neutral but it is not the 2.5k rev limiter set by the maf sensor but a weird hesitation. It happens wether hot or cold

POSSIBLE SOLUTION: The only thing left i started to look at today was the knock sensor, i read many threads about it so i started testing today. When the manifold was out..the sensor looked in great shape so i didnt worry about it, continuity exist from the ecu pin to the conector...however wen i disconect the knock sensor conector from the engine harness, nothing happens and the car still has the hesitation and the check engine light does not come on.is this normal??

I am thinkin there is a problem in the wire that conects the knock sensor itself to the engine harness(runs inside intake manifold)...one of the pins should have continuity with ground but none of them chek out...


Do u guys think this is wat is makin my baby run like that?...I mean how should the car run if the knock sensor was disconected?..i get no engine light on and the car runs just as b4 with the hesitation...

HELP GUYS

THANKS

[dued]

Clutch.

Your clutch could be slipping.

[Z U L8R]

are you using the stock intake piping or do you have like a cold air intake aluminum pipe thingy.

btw i check your tps 1-5 volt sensor wire at the ecu with a digital multimeter with the ignition on with the throttle closed and opened 0-1 volt closed and 3.9-5volts when wide open is what you're looking for.

gl mang =]

Dave =]

[osal]

thanks guys ...but wouldnt the tps give me idle problems?....


-clutch doesnt feel like it would slip but mite look into that

wat about the knock sensor...i disconnected it and i ran the same..is this normal???

[Z U L8R]

no. do what i said

[Giebs]

when checking the tps u really want to check the voltage between WOT and idle. need an oscilloscope for that. you wanna see if the voltage increase is smooth and even as you move the throttle.

[osal]

ok so i bought a new tps..put it on...but cant really get to adjust it to the rite voltage...however i was readin some other threads and got some ideas and will try again tomorrow......

one question though...how should the car run without it being connected..?..my car runs exactly the same..with good idle and horrible acceleration..and no chek engine lite..any thoughts?

[xsparc]

the gnd for the knock sensor wont pin out from the harness. its a floating gnd. the sensor is grounded to the block throught the casing.

with the tps disconected, it will idle a little higher.

[Z U L8R]

i didn't say to BUY a tps.

i said to check the voltage going to it.

for the record, yes a tps can cause idle issues as well as driveability issues. what's the story with the car now?

Dave

[osal]

well i bought a new one because the old one did not chek out with the correct number of kohms.

[osal]

well i got the new tps adjusted to .5volts...still very poor acceleration..i m about to make a video maybe that will help to diagnose better

[Saviorsoul]

:squint: ...Have you checked your TPS?

[Saviorsoul]

well i got the new tps adjusted to .5volts...still very poor acceleration..i m about to make a video maybe that will help to diagnose better

If I remember correct its suppose to be at 4.5v at idle

[Saviorsoul]

i
POSSIBLE SOLUTION: The only thing left i started to look at today was the knock sensor, i read many threads about it so i started testing today. When the manifold was out..the sensor looked in great shape so i didnt worry about it, continuity exist from the ecu



In every situation I've PERSONALLY seen, if its the knock sensor it throws a engine code. Also I don't "beleive" under normal conditions the knock sensor would effect your driving. It's suppose to (i think retard) your timing if you start getting pings. :ugh: Don't trust me on that, someone correct me if I'm wrong.

[osal]

this is wat 240sx faq says
5. Adjust by rotating Throttle Sensor body so that the output voltage is 0.45 - 0.55 volts....

[xsparc]

In every situation I've PERSONALLY seen, if its the knock sensor it throws a engine code. Also I don't "beleive" under normal conditions the knock sensor would effect your driving. It's suppose to (i think retard) your timing if you start getting pings. :ugh: Don't trust me on that, someone correct me if I'm wrong.

the KS will throw a code, but not a CEL. It cause a heasitation at about 3k, not lack of power.

[HemiCharger]

Perfect KA fix.

1. Remove Engine
2. attach 25 feet of chain to the front block tow
3. Prepare fishing reels, lines and lures.
4. Put said KA on your boat from step 2
5. Get lots and lots of beers and friends for the trip
6. go out to the middle of your favorite fishing spot and dump the KA over board after having attached the other end of the chain to your bow.

Enjoy the rest of your afternoon.

KA24DE the perfect boat anchor......

[osal]

lol no man that s not an option...i was actually impressed to have 180ish psi of compression along all cylinders...i cant give up on an healthy engine liek that

[Z U L8R]

adjust your tps so it's over 4 volts wide open throttle, and under 1 volt with the throttle body closed. then lets move on

too wide of a spark plug gap will cause it to break up under load. u may want to pull em out and check the one's you put in. and if they're bosch x9 platinum bullshits throw them away and put in the factory spec ngk plug.

when you changed your distributor did you put a new distributor cap on it with a new rotor button?

does your distributor have an internal or external coil? in other words do you have 4 or 5 wires going to your distributor cap?

Dave

[osal]

umm okey when i put the new spark plugs they were ngk platinum tips and there s a sticker on the engine bay that says that platinum tip spark plugs dont need adjustment..however the car was also running like shit with the old ones....

Yes distributor has a new cap and also rotor...as well as spark plug wires.
And also the distributor contains an internal coil and it should be new since the dizzy is new as well

I m thinking of another possibility now...do u think maybe my cam timing is out of spec maybe the chain jumped a tooh or something?...although the only time i took out my valve cover was wen i removed the chain guides..

i m goin to take a picture and show u guys

thanks 4 ur help guyss...

[napz510]

Maybe you have a vacuum leak, why don't you install one just to see what's your vacuum and it should be at 20.

[osal]

well wen the intake manifold was out..i replaced most vaccum lines...even replaced my intake mani gasket...i m runnin out of ideas

[LetsKillKevy]

Not sure if this has been said elsewhere, but I have had a similar issue about a year back and all it turned out to be was a slightly clogged injector, of which I had a full used set laying around. Injector could flow plenty of fuel at idle to about quarter throttle but couldn't flow enough for pedal to the metal driving and would give a slight sputterish, hesitation. Just something to think about if you haven't checked the injector/ signal to the injectors.

[97KATURBOSILVIA]

Exactly what i was thinking, should be easy enough to check too. GL your doing all the right things, ever try switching out the ecu also. Just because it reads codes doesnt mean its functioning properly.

[osal]

i am about to buy another ecu from this zilvia member..so i ll chek on dat....i ll check injectors too, i only cheked by unpluggin each one while the car was running and the idle changed so i assume they were good..but i will chek fsm to chek the ohms....

i have a question thou...i bought this conzult cable from ebay and i have a software for it...however my computer does not read it...i m wondering if it is because i have vista or maybe the ddl connector is not workin, is there a way to check that connector to make sure is workin??..

[shift_tommy]

With the car idling, disconnect each injector and see if the idle decreases and reconnect it. Do it to each injector. The injector that does not cause the idle to stumble should be the culprit. Also, check if you are getting spark to each cylinder. Seems like your car is misfiring. I had this issue before and checked both spark and fuel. Turned out it was a fuel injector.

[osal]

yea i already did that test of unpluggin each injector while the car is idling..when i unplug any of them, the idle changes so it should be good.

[darkslide]

i am about to buy another ecu from this zilvia member..so i ll chek on dat....i ll check injectors too, i only cheked by unpluggin each one while the car was running and the idle changed so i assume they were good..but i will chek fsm to chek the ohms....

i have a question thou...i bought this conzult cable from ebay and i have a software for it...however my computer does not read it...i m wondering if it is because i have vista or maybe the ddl connector is not workin, is there a way to check that connector to make sure is workin??..


do you have any buddies with a s14 maybe u can swap the ecu b4 buying another one, kinda to verify that its the problem b4 you waste some cash money

is the software from blaZt? if so they got a FAQ section
http://www.blazt.biz/forum/faq.php?sid=088f0095392c354a4fa36e993c00ba17

also might wanna check this one out
http://202.43.230.118/

[Bboy/dorikun88]

hey man now when yo say hesitation what do the rpms do does it kinda fall on its face a lil then pick right back up or does it just give a slight buck and then go?

[osal]

no, after 3k rpms acceleration is really sluggish..thats in every gear.

anyways i was looking at the fuel pressure regulator...i unplugged the vaccum goin to it and run with it disconnected...no change at all ,the car still runs like shit...does this mean my fuel regulator is shot???...i mean i already changed my pump to a walbro and also the fuel filter. Let me know wat u guys think
thanks

[osal]

anybody has some ideas about the fuel pressure regulator??

[bo2o]

advance your timing to 15 btdc try that out. close gaps a lil on spart plugs

they say run .o44 run .o35

add more grounds. check fuel pressure. change fuel filter, fuel pump.
300zx fuel filter.

[xsparc]

.35 should help out, it did for me

[osal]

well i already added grounds, changed fuel pump and put a new z32 filter...i m goin to try changing the gap of the plugs....

but wat about the regulator...how should a car run with the vaccum line disconnected...obviously the idle is going to be a tad high cuz of the vaccum leak...but when it comes to performance, my car still runs like shit which make me believe a have a faulty regulator.. a fuel pressure check would determine that but i dont have a vaccum pump in hand to test the regulator...However, in theory dont u think the regulator is bad ?since all other components chek out such as fuel pump, filter, injectors.
let me kno wat u think..thanks

[orion::S14]

EGR might be failing, allowing exhaust into the intake manifold all the time (except idle)...block the port in the exhaust manifold with a nickel...to stop flow through it.

Just unscrew the pipe, flex it out of the way. Pop a nickel into the hole. Reinstall pipe.

See if that heps.

- Brian

[orion::S14]

...and/or check the fuel pressure, -OR- try a known-good FP regulator.

???

[darkslide]

no, after 3k rpms acceleration is really sluggish..thats in every gear.

anyways i was looking at the fuel pressure regulator...i unplugged the vaccum goin to it and run with it disconnected...no change at all ,the car still runs like shit...does this mean my fuel regulator is shot???...i mean i already changed my pump to a walbro and also the fuel filter. Let me know wat u guys think
thanks

how is your car under wide open throttle? because if ur fuel pressure regulator is bad, it shouldn't make a difference under WOT. im sure it would cause some issues starting maybe and at idle but if you cant get the car up quick i dont think its your FPR ( dont think i am but if im wrong someone lmk).
have you got your conzult to work on your laptop yet? that would help u out. also have you checked signal voltage and grounds going to your tps and maf? and hows your egr? while the car is running lift the bottom of the diaphragm up to see if ur car boggs out

[osal]

wen i took the intake mani out,i cleaned the egr and changed all lil vaccum lines around it...yes the egr cheks out since the car does want to die wen i push on the diaphram. i already replaced the tps and set to the correct voltage.

[osal]

well i checked my injectors ohms and o-rings...all check out..however 2 of my injector have the lil teeth at the bottom broken off...will that make me run rich?