Hesitation?

[JasonNagra]

Just came back from the track on the 19th and I just changed the oil and cleaned up the car. However, now ever since the track (even before the oil change) I get a stuter under acceleration at around 2200-2800 RPM. Car does when engine is cold. The car is fine till those RPM's, and then is hesitates a bit. Visually everything seems to be fine. Any thought guys/gals? All input is appreciated as always.

[JasonNagra]

Oh, and its on a 91 KA24DE.

[deejayS13]

yo mine did the exact same thing...same engine...now i gotta blown rod...and on the way to sr20det-ness in nov!! some things were meant to happen.

[deejayS13]

my bad i'm an ass...i got the old engine didn't mean to scare you.

[240silvia]

I have a 93, but my KA used to do that. I tried resetting the computer several times and everything. The only thing I didnt' try before the SR was checking the plugs to see if they were fouling out.

[JasonNagra]

Well, I've been doing a lot of seraching on multiple forums. So far I am going to:

Check Timing
Check TPC
Replace Fuel filter with Z32
Replace all plugs and wires (the cap and rotor are fine)
Replace O2 sensor
Run through some Motul injector cleaner from PDM


It is time for my cars yearly maintenance anyway so its cool. Let me know if you guys think this is enough stuff to MAYBE get rid of the problem. Any other ideas weould be great. Thanks, Jason.

PS from searching it seemed like most things that caused hesitation under acceleration was fuel.

[RedlineRacer]

Mine does the same thing. I got a DE and its only in that rpm band that it does it, and it makes shifting a pain in the ass sometimes. I thought I might have air in my clutch line, cause that rpm band is usually were I always change gears at. But, it might be something in my engine. I also changed my fuel filter and my air filter. Does it do it for you in nuetral? Cause it doesn't for me.

[Got Sileighty?]

whoa! mine does the same thing, between 2200-2500 rpm, it hesitates for a sec. and it usually only does it in 2nd gear, sometimes 3rd. oh and it usually only happens after startup (like in the morning on my way to work). mine's also a 91 DE.

ive already changed air and fuel filter. im gonna chnge my plugs on my next oil change, ill see if that helps.

[JasonNagra]

I will check and see if it does it again today. Haven't driven the car in a day. I don't think it does it in neutral. I'll get back to you guys on this after I drive it.

[Dousan_PG]

jason: lindsay has the rear hub..ill call him and see when you 2 can meet up

[JasonNagra]

Word. Just call me! Thanks again Aaron. I think Omar and i are going to throw it on cause he has airtools and the big a$$ 32mm socket to get the hub nut off.

[andrave]

my car stutters up from like 3k-4k or so, but it sounds like the same thing, only under WOT. this is on a ka24E that is soon being swapped for a ka24de turbo.
if you ever find out what is wrong please share, I've fixed lots of things but the problem is still there.
recently I've wondered if it could be tps or mafs but thats just guessing.


"Well, I've been doing a lot of seraching on multiple forums. So far I am going to:

Check Timing-
done it, changed it, doesn't affect it.
Check TPC-
not sure what that is.
Replace Fuel filter with Z32-
done it, no change.
Replace all plugs and wires (the cap and rotor are fine)
done it plus cap and rotor and coil, no change.
Replace O2 sensor
done it, no change
Run through some Motul injector cleaner from PDM
used cleaner several times, no change.

[JasonNagra]

Well I am also going to be cleaning out the throttle body as well.

[RedlineRacer]

Originally posted by andrave
Check Timing-
done it, changed it, doesn't affect it.
Check TPC-
not sure what that is.
Replace Fuel filter with Z32-
done it, no change.
Replace all plugs and wires (the cap and rotor are fine)
done it plus cap and rotor and coil, no change.
Replace O2 sensor
done it, no change
Run through some Motul injector cleaner from PDM
used cleaner several times, no change.

To add to that list:

I've checked my mafs to see if it was dirty or if the harness wasn't tight and that did nothing.

What about IIAV or whatever it is? Someone told me to check that, but I don't know what it is (and I searched). What about the butterfly things. Does the KA-E have those too? Or is it just DE?

[JasonNagra]

Actually I removed my AIV just yesterday if thats what you're talking about. Its the little resonator box in your engine along with few other parts under it to heat up the cat during startup to help emmissions, it was dumped on the S14 because I geuss Nissan thought it was kinda a waste (the ecu helps start up emmissions by leaning out the fuel on S14s). I didn't notice too much difference after doing it, just cleaned up the engine bay which is fine by me. Just need to get the hole on the exhaust mani welded close, dont care for using the plug.

[JasonNagra]

OKAY!

My hesitation problem is SOLVED. I talked to "1bad80sx" on freshalloy about my problem. Well he reccomened me buying some throttle body cleaner and REALLY cleaning out the throttle body. I had never done this on the car, and I felt kinda retarded for not thinking about it earlier. (I mentioned it above, but that was after his help too) Well I disconnected the intake hose going to the TB, and WOW there was a 1MM thick layer of black soot around the inside of the TB. So I started to spray that down and wipe away as much as I could. I did this while having the car started, opeing the TB, and did it a few times while the car was off then starting it to let it flush out. Some black smoke came out the back while doing this too. I then shut it down, inspected the TB with a flashlight and it looked VERY clean, nice and shiny. I also made sure to clean the back of the plate too. Basically I cleaned everything I could in the sucker w/out removing it. Removing it is also a good way to do this (much more thorough) but you have to buy a new gaskter and you must have allen sockets cause those allen bolts are on there TIGHT! After spraying the TB again heavily just to make sure it was super clean, I let it sit for a mintue, and then let it idle for about 3 minutes. The first 30 seconds of idle were rough, and then it smoothed out. I then took her for a spin, and the hesitation was GONE and the car just seemed smoother. Well I hope the rest of you try this because it only costs like $2 and is good maintenance.

[andrave]

driving into autozone NOW!

[JasonNagra]

Yes I got the STP throttle and intake cleaner, like 2 bucks. Let me know if it works for you too.

[andrave]

alright well after cleaning my TB I found this:
the stuttering I was experiencing all over the place now occurs at 4500 rpm under more than half or 3/4 throttle. If I give my car some gas at idle it revs up to 4500 and cuts out and won't kick back in till the revs drop. This happens at EXACTLY 4500 rpm, no where else....
anyone... anyone???

[JasonNagra]

Try to clean the TB itself by taking it off. Its not too hard as long as you have allen sockets and make sure you get a new gasket. It seems like the stuttering problem does lie within the TB because it has fixed mine and marginally fixed yours too (atleast its not all over the place). Just take off the TB and soak it in cleaner. Worth a shot.

[andrave]

no allen head sockets down here. And I'm swapping this winter... wonder if its even worth the time.
Might try it this weekend.
I haven't ever changed my aic valve or whatever that thing is on the firewall side of the intake mani.
If its in the throttle body what would make it happen at exactly 4500 rpm... I wonder if its not tps or something.

[JasonNagra]

Try adjusting TPS. If your swapping soon, then forget it I geuss. What do you mean no allen head sockets? There not available where you live or you just don't have any?

Anywho my thought is why its happening right at 4500 rpm cause of the TB is maybe because there is a certain spot that might be clogged. I dunno just worth a shot if you care. I plan on staying KA for alteast a year so its worth it to me.

[andrave]

oh I'm staying KA, for sure. I'm gonna be dropping a warmed over dohc in place of my sohc and strap on a turbo.

Anyway I think its electronics, its too consistant and too precise to be just a build up or something...
Thats just my opinion, but it makes sense to me. Now I just gotta out what it is!

[RedlineRacer]

I tried cleaning the throttle body. I didn't notice much of a difference. Maybe it's cause I used a carb cleaner. Are they any different? Anyone know much a new EGR is? I tried playing with it to see if it could be the problem. I read my Chilton's manual on it. And it said if it is in good condition, then you should be able to open it, then release it, and in 30 seconds it will close. Buy, my closes right when I release it.

[JasonNagra]

Hmmm. Maybe we should look into the EGR a little more too. I will, and look more into the 30 sec redline, caue I don like chiltons. For stuff like this i will consort the s13 bible (fsm).

[twitchy]

sorry to bring this thread back

does anyone think hooking the car up to a diagnostic scanner would give any insight to the problem..Ive cleaned my TB and no change really. Tonight the problem is getting bad and its frustrating me too much to drive....i spun the tires twice i never do that.