I've had an idle problem ever since I installed a JG 1001 cam, but I don't think the cam is the reason: When started cold...the idle will be low, then start to climb up little by little to a nice cold idle at 1500 or so. When I get in the car (after it's warmed up a lil) and blip the throttle to drop the revs, it'll almost die, and sometimes does. When the car has been driving for a minute or two, the idle will be fine, at the norm ~650. But say I go in a store for a second, come back out and start the engine (still warmed up) I'll start it and it'll idle super low, or die. I usually keep the revs up by holding the gas for a minute or two, then the idle will be fine. I can live with this, but it's annoying as HELL! Anyone have a clue what it could be? thanks, -sean

 

what controls idle is, ignition timing being perfectly tuned, vacuum lines are sealed and either go somewhere, or completely sealed off.

MAP sensor controls idle, as well as IACV, no air bubbles in coolant at all, as well as the idle screw in the throttle body.

 

ignition timing is fine, don't think I have a vacuum leak, and i'm going to clean out my IACV tomorrow probably. What about the fast idle valve? think that could be a possibility? what about that vacuum dashpot on the tb? what the hell does that do? btw, engine is a d16a6. -sean

 

don't know about your car cuz you didn't say what was it, yes, FIV (fast idle valve) can do this, try disconecting the FIV set the idle with the screw and plug in the fast idle valve, and let it run a bit, then pull the computer fuse, let the car turn off, wait like 10 min before putting the fuse in, put it in and start the engine, let it idle for like 10 min without touching the gas pedal.
And idle is supossed to be 700 ± 50 RPM, so if i was you i would set it to 750 RPM
if it doesn't work let me know

EDIT: before disconecting the FIV you have to jump the service connector


[Modified by GZERO, 9:16 AM 10/22/2002]

 

sounds like the TPS sensor is starting to age. this happens to alot of cars. sometimes if the throttle plate gets sticky, it causes this. have you messed with the air screw on the throttle body at all?

 

Yeah, could be TPS. You can measure the voltage with a DMM to see if things are reading correctly or pull off the throttle body and clean any build up off of it. My guess would be something to do with the IACV or FIV. You can take off the IACV (should be on back of the manifold if I remember correctly) and clean and black build up off of the small screens. See if those help at all, I'm slow I'm going to have to sit and think for a minute to figure out what might cause what. If I think of anything I'll get back to ya.

 

mann there has been a lot of posts recently on "Idle".
we should make up an Idle Guide.



[Modified by Quick 200k Mile Motor, 10:00 PM 10/21/2002]

 

I think the easiest solution is to just get a block heater for starting and then never stop while driving you car

 

The cams just might be the problem.

Once I adjusted my valve clearances too tight (opens the valves more) and the car would die after it warmed up.

 

my valve lash was pretty tight before, but now it should be fine...it's only when the engine is not fully warmed up...even if i'm driving for a while, then let off the gas it'll almost die...it goes to about 200, then jumps back up and idles fine.

what catches the idle on the way down? and what's that dashpot for on the tb?

i have tomorrow off so imma **** around with it.

 

iacv and dashpot catch the throttle on the way down. The dashpot is supposed to keep it open a little just after you release the throttle, that helps prevent stalling. The cams have got to be it. Crower cams lash specs are the same as facotry just engine warm instead of cold. The same thing can happen. Dont worry about it. If it bothers you, loosen the idle air bypass screw a little, it should prevent it from diving so low and hopefully it'll still be within range for the iacv.

 

You should also realize some of the effects that come about from putting in a 'hotter' cam.

Decreased vaccum at idle is one of them and will certainly cause an unstable idle if the cam is too 'hot'.

Try raising the idle a bit to see if that will help even things out. Follow the Helms manual for instructions on performing this.