# engine idle high and stuttering and choking



## Alchemy (Dec 9, 2004)

i just got my engine rebuilt about 2000 km ago on my 87 nissan pulsar nx with the e16i engine in it. the car idles at like 2000 rpm when its warm or it drops to 300rpm and almost dies. also , while driving , if u hit the gas 1/2 of more the engine buckles quite often , feels like the engine is choking.

i got new plugs , new wires , i checked for vacuum leaks , i used throttle body cleaner to clean it out, and still does the same thing. i just ordered a new throttle position sensor so hopefully that fixes it.

but if not,what could be the problem?


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## Slacky (May 31, 2004)

timing... or idle set


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## recycled_toddler (Feb 4, 2004)

I'd check the Idle Speed Control (ISC) solenoid on the right rear of the throttle body; It could be sticky. You could always get another one out of the junkyard and swap it out. The solenoid looks like a small aluminum can clamped to the throttle body at the right rear, with a pigtail going to it. Worth a shot, anyway...


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## Alchemy (Dec 9, 2004)

i replaced the tps last night and it didnt fix the stuttering problem , its gettin bad now , sometimes the car almost dies in the middle of driving along for no reason. could it be a fuel problem?


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## Slacky (May 31, 2004)

well its not a tps its a idle speed control valve did u check that?


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## Alchemy (Dec 9, 2004)

the white connector on the pass side at the back of the throttle body?


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## Alchemy (Dec 9, 2004)

how do i check the ISC valve and where is it?


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## Slacky (May 31, 2004)

its a solonid white plug off of it, has a little metal clip holding it on anyway what your describing let me just ask again when u floor it or give it gas anywhere past a quarter pedal or try to bring it past say... 3 grand it dies for sec then revs back up and dies over and over and over? as if to have only one cylinder firing? if so when it starts to do that put your hand on the right side of the throttle body and rev it up by hand and give that solonoid a good wak while its "choking" if it revs up good dont get your hopes up because as soon as it goes back to idle it wont rev up good again but then u would know that its the problem for sure, and its like a hundred bucks for a new one so try a junk yard out


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## Slacky (May 31, 2004)

o yea forgot the solonoid is on the back left about 4 inches long and 2 or so in diameter


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## Alchemy (Dec 9, 2004)

ive only noticedi t happening when the car is under load, usually when i give it 1/4 pedal or more , it drops down like 1000 rpm sometimes while driving and it fluxes down and up for a couple seconds then goes back to normal, other times when accelerating at a constant rate it starts to buckle for a little bit and feels like its losing some of the accel power


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## mille-16i (Jun 16, 2004)

mine has similar issues I have messed with everything replaced the fuel injector replaced the mass air flow the tps the coolant temp sensor checked the iac valve for proper operation the manual gives a good description and I also replaced the ecu. Now the ECU replacement yielded the most results lost my rolling idle it would roll from 1800 to 400 if I lowered it anymore than 1800 it would die out the stumbling has not gone away how ever has gotten a little better. I am thinking it might be in the distributor the magnetic pick up might be acting up I don't know if this helps any hope it dose. with mine if I am not hard into it I can pull right up to redline.


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## Slacky (May 31, 2004)

sounds like iac valve acting up alright, if it gets progressively worse liek i described then check it out, mine got to the point where it would only run right for the initial start up inthe mornin for about 5 minutes until it go warm enough to malfunction


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## Alchemy (Dec 9, 2004)

mines been gettin worse over time, how do i adjust the iac ? replace the solenoid(im gunna get one this weekend)?


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## recycled_toddler (Feb 4, 2004)

Just don't you forget who first brought up the possibility of the ISC solenoid....y'hear? Yesterday at 10:11...


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## Alchemy (Dec 9, 2004)

yeah yeah , and i know who to blame if it doesnt fix it


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## Slacky (May 31, 2004)

lol yeaa, anyway i never tryed it but i heard of this dude who just took it out and sprayed it with brake cleaner and worked it a bit to fix them but i think thats if they are just gunked up from old gas i dont think it would work for one that is just shot, but give it try and see if it works and if it brakes it.... blame toddler heh no im just kiddin see what a more experienced person says to that idea before u go and mess something up if it isnt bad to begin with


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## Alchemy (Dec 9, 2004)

the cost doesnt really concern me to replace the solenoid . i just really badly want to my pulsar to run properly


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## Slacky (May 31, 2004)

well then, hundred bucks, auto zone, if it works great , if it doesnt then bring it back


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## mille-16i (Jun 16, 2004)

if price is not a concern just take it in and have it trouble shot it should only cost you 300 adn atleast it will fix it right now you have probally 60 into the tps and posably 100 into a Idle air control if that don't fix it that could suck all my parts were wrecking yard parts not new, E16i parts are not cheap


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## Alchemy (Dec 9, 2004)

ive taken it to the nissan dealership and they had no idea what the problem was , came up with no error codeso n the comp or anything... and they charged me 80 bucks


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## Alchemy (Dec 9, 2004)

i went to the wrecker today and got a idle speed control solenoid with the valves on it. ill pop that baby on tmorow after work and hopefully thatll fix my problem. cost me 8 bucks from the wrecker cause they didnt know what it was lol


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## Alchemy (Dec 9, 2004)

i put in the solenoid and it seems to have fixed the idling problem , but the car still chokes when u give it lots of gas or when ur goin 100km/h + when the engine is warm :s


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## Slacky (May 31, 2004)

hows the timing on the distributor, if its too advanced it will idle higher but u will get bad top end that results it studder and choke after a certain rpm


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## Alchemy (Dec 9, 2004)

the timing is perfect , and when the engine is warm , its not a lil bit of stuterring and choking, sometimes it almost dies


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## Alchemy (Dec 9, 2004)

i think maybe its the o2 sensor. is it on the driver side of the engine? and if i unplug the o2 sensor to c if it helps and to try and isolate the problem will i hurt anything?


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## Slacky (May 31, 2004)

mmmm dont think so, kinda like poppin aplug wire off too see which piston would be misfireing so idk i say go for it , un plug it and see if it runs any crappier


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## Alchemy (Dec 9, 2004)

well, that didnt help lol , so im guessing maybe its the ignition coil


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## Alchemy (Dec 9, 2004)

its been a few weeks since i replaced the solenoid and its starting to have the idle problems again. so could something be wrecking the isc solenoid? what could cause that? and my car still buckles/chokes when its warm, especially at speeds above 80km/h. dont think its the afm cause wrecked afm's make it so u cant rev high, and i can rev it to 6200(the redline on e16i) fairly easily


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