Car can't decide where to idle

[morpheus8486]

A few days ago my car started running weird all the time, where it used to just do this every now and then. I'll start it up and will idle at 1500 rpm for a couple minutes and then will settle back down to 700 rpm where it should be at. And then it will just flucuate and gets down to as low as 100 - 200 rpms. And then when I shift into neutral to stop sometimes the whole thing will shut off. Its pissing me off. I replaced spark plugs, air filter, and the battery (it needed to be replaced anyway). It ran like a dream for a day and now its being ghetto again and I'm getting pissed again. I've searched and found it might be a vacuum leak, and I went under the hood to see if I could hear anything but couldn't. Is there another way to check for a vacuum leak? My other thoughts were a clogged fuel system. I've ran seafoam through my car a couple of times, but is there any more effective way to clean the fuel system? Are there any more possiblities I might be forgetting?

[thejester03]

Ha, Im in the same boat with my 93 coupe. The idle control valve could be it, i cleaned mine, and it seemed to help, gonna do it again in a few days. If any one else has any ideas, let us know.

[morpheus8486]

hmmm...the idle control valve huh? I'm guessing that's in the throttle body right? I should just clean the whole thing cuz my engine bay is pretty dirty.

[redsuns3838]

i had the same problem as u altho not as extreme but, try taking off off ur IACV. if u hav a S14 motor ur in luck, S13 mite be a lil tougher. check a FSM for where it is,. S14s is next to the top of the mani and really easy to get at. S13 is between the two halves i believe. if u do a search on nico or maybe even on zilvia there is a how to clean AICV article. its for a KA but location is similar for the S13 SR motor.

anyway just clean the hell outa that thing with carb cleaner and bolt it back up and see how the car runs. mine ran a steady 800 rpm idle for the past 6 months after i cleaned it out.

also, another way to test vac leaks is to get some soapy water and drip it on all the couplings and pipes and then when u open the throttle if theres a leak u will see bubbles.

goodluck mang

[Sanchi]

Clean your throttle body!!

[thejester03]

The idle control valve is kind of in the throttle body curve, in the back, you can pull the hose off the intake and spray some throttle body cleaner in there, then run it imidiatly, it will run kinda funny for a sec though. I did mine again today, and seems to help a little more every time i do it.

[sgvis300]

clean out your throttle body and maf sensor. ECT sensor should probably be cleaned out too. trust, its a common 240 thing.

[AlligatorBling]

seafoam mofo!

[morpheus8486]

seafoam mofo!
I actually ran some seafoam through the engine the last time I changed my oil, which was not even a month ago. Maybe some more is in order? I should run a can through the fuel system, but I dunno. Cleaning the throttle body and all the other random sensors and bells and whistles you guys are talking about sounds like a good idea. Too bad I wont be going home to have a garage to work in anytime soon. Maybe I'll just go get a socket set and go to work in the dorm parking lot. And btw, what's the ECT sensor? Or at least what does it stand for? It's late and I'm feeling lazy.

[morpheus8486]

And I removed the AIV system a little while ago if that makes any difference. It didn't start consistantly acting weird like this until recently though.

[sgvis300]

engine coolant temp sensor, it tells your car that the engine is warmed up to go into closed loop. and for shits and giggles, try and put the aiv back on and see if it fixed the prob.