Idle problems..again..

Took my car out for a spin down the road and pulled over..let it sit for alittle bit while a ran a quick errened..wasnt gone for more than 30 seconds and the car shut off..Tried to start it up..turns on but it idles at about 600 and slowly drops to about 400 then shuts off..if i give it gas the rpms will go up but slow then start to drop again quick. The car putters bad when its sitting there and the rpms are dropping like its struggaling bad. Dont know what it could be. Any help? Taking it into a friends shop soon anyways but wanted to see what you guys thought

try the tps, throttle position sensor or the iac, idle air control. i'm not sure about the turbos but on the non-turbos they are both located on the throttle body, the tps is the top one and the iac is the lower one. try checking those and see if that helps

Anyone know where it is on a turbo car?

i'm guessing it's still on teh throttle body, i'm not exactly sure where though. if you un-plug it, the rpms of your car should increase, at idle, but don't take my word on that.

you can also try to see if there is oil in your spark plugs that happend to me once it kind of stumbled and then died after i cleaned the oil out it didnt do it anymore btw my valve cover wasnt leaking what happend was i accidently spilled oil in to there at night.

The car putters bad when its sitting there and the rpms are dropping like its struggaling bad.


Have you looked at the throttle body plate and such? Mine had carbon built up and made it idle pretty low... stemmed from the oil coming through the breather hose and going through the intake system....I still have to take intake manifold off to clean it out and maybe port it while i'm at it... kinda carbonE inside but intake cleaner and a tooth brush really helped.


Still wondering why my teeth turned black for awhile....hee hee.......... :icon16:

Did you check your gas gauge?? Har Har Har

Fuel filter? Plugs? Wires? Git'er done

i am getting the same shit from my 99 rs but the only thing is mine blow smoke once in a while.. i took to the dealer they say it's my valve seals.... do u burn oil??? if so it might be the problem....

I dont think i burn oil no..how would i adjust the TPS on a turbo car?

SO... if you are going to adjust the TPS how would I go about it.... I know there are the two screws... do I just loosen both a little and turn it a little?
Would that/can that change the idle speed?

dont fuck with the tps without a logger of some sort to tell you what reading the computer is seeing. the biss is how you adjust your idle its the plastic screw on the throttle body sometimes has a little rubber plug covering it. if the tps isnt adjusted right the computer wont ever go into closed loop idle circuit and it may run better but your gas mileage will be crap and its not good for the engine.

its probably your isc(idle speed control) motor it lets extra air in past the throttle plate to raise or lower the idle speed when its just sitting or you turn on the ac, etc anytime the engine gets a load and the throttle is shut. search on here or vfaq will tell you how to test it i dont remember the values your looking for but you test the resistance of each coil. do a search and youll find it.

i just recently did the test myself. i too am idling rough. stall and surge. turned out the resistance of the coils on my ISC was off. they were around 42-47 while the standard should've been 28-33. it's a common failur in our car. i've just ordered a used one from tuner classfields for $45. don't get a new one from the dealer cause they'll charge you $200 for one. look under Vfaq's intake section on how to diagnose idle surge. it most likely will be your ISC, TPS or dirty TB.

at this point i am just hoping that it's one of them and not more than one. still waiting on the ISC.

does the idle sometimes varies at the light? sometimes when it's low the needle shakes? when you turn on the AC.. do you see your idle shoot up? all these are signs of a BAD ISC. playing with the BISS will temperarly get you to not stall. before you get a new ISC.

I know it's your thread, but this is very related. I have high idle when the motors cold, when it warms up, it goes back to normal, but i also have idle surge, not bad, its sounds really bad, but the tach increaes isn't noticable. I believe this would be fixed by adjust the biss, correct? I've read the vfaq, and it seems right, but i really want to make sure before i go trying stuff, i don't have any other car incase something goes allittle "off".

just remember how many turns in which direction you turn it so that you can put it back if it makes it worse

unless somehow the BISS falls lose, chances are the real problem lies somewhere else. adjusting the BISS only masks the problem. something might still be wrong with your idle control system. i'd say check the obvious too. TPS, ISC, TB. 2c

My S-AFC was all fucked up with the bigger injectors, so im replacing my plugs tomorrow and see if that works. If it starts up i gotta start tuning it again. If it doesnt, back to square one.