Whats wrong with my idle please!

[cadence_1]

What would cause the idle to:

1. Idle at 1500rpm and stupid rich! 10:12. After unplugging IACV car jumps to 22-2500RPM and 11.2:1

This leads me to believe the IACV is working but either not working properly or something is just amiss?

Could a vacuum leak cause this somehow?

I have hunted for an fixed various vacuum leaks (pressure tested) over the past few weeks. Fuel pressure is set properly, maf has been cleaned, Car seems to run fine. Just nasty high idle from cold start all the way through warm up. And stupid rich! And it will stumble when I tip blip the revs and let them fall. I assume this is just cause it is waaayyy too rich, but who knows at this point.

I'm not throwing any codes. It doesnt make any bit of difference whether the coolant temp sensor is plugged in or not.(should I notice some change when unplugging the CTS while the car is running?)

Has anyone experienced this before?

Thanks for any light you can shed on this subject.

[sjbsuperman1425]

there is a screw underneath the throttle pulley. it may be up to far? did you try adjusting the idle via IACV? also, how do you unplug the IACV?

[cadence_1]

By unplugging the iacv I am referring to unplugging the solenoid that controls the idle. It's how your supposed to adjust idle. Unplug it when warm, set idle to 650 or so. Plug it back in an the idle is supposed to raise up to 750-800. Well that kinda works accept the idle starts at 1500 and. Rasises to 2200ish when I plug it back in.

I haven't messed with the screw, but this car used to run fine(atleast it would idle anyway). So I just don't see that as the problem. I'll check it though.

Is there a resistance spec for the CTS so I can check that?

What else would make this car run so damn pig rich? Argh!

[ca18detgabby]

a vac leak could easily do that.

what is your a/f and vac at idle if you know?

[cadence_1]

Well.. problem is I don't have an "idle" so to speak cause it wont go below 1500. so vacuum is great at that rpm! haha! But A/F is horrible around 10:1. Hell, could be richer, that is as low as the AEM goes so? When idle goes up to 2200 (after plugging in the iacv) A/F goes to 11.2

I have pressure tested this thing countless times now and I cant find anymore leaks. I would think that if I had a leak bad enough to cause this I would be able to track it down somewhere easily. But I am open to anything.

Injector seals maybe? Wouldn't you hear air hissing out of them?

[ca18detgabby]

well even at 1500 it is still offically idling........

what is the vac at that point?

try unplugging the maf and see where it idles?

did you play with the tb set screw at all?

[dattodude]

at 1500 rpm you've got some sort of air leak..

using some smoothish vice grips (or brake line , block off the air supply to the idle control block by squashing the hose that feeds the idle control block.

If the car won't start or idle without the idle control block, then it's the idle control block causing problems..

The AAC will likely be stuck off it's seat from gunk and funk.

But it could also be the throttle is also gunked up, worn out, or adjusted open too far by some wangan racer..

[cadence_1]

Ok. I will give blocking off the air supply a shot tonight and see what happens. I cleaned that bad boy a while ago as well. As for the throttle body being dirty. I cleaned the living hell out if it the other day cause I thought that might be a problem. The set screw I don't think is the problem because this car used to idle. But I will look at it again. Is there a proper way to set that screw so I know it is correct?

[CakeEater]

I had this very same problem 3 days ago...it turned out to be the little rubber plug i had on the bottom of the TB had cracked and was leaking. New plug and it was at 850 like it should be.

Have a look at that?

[cadence_1]

Really? No I haven't looked there. Was it running pig rich too? I just llooked down there and I don't see anything that looks out o the ordinary? Can you possibly explain your symptoms and how you came to find this solution?

Thanks!

[float_6969]

As others have said, it sounds like you have a vac leak somewhere on the intake. Start removing vac lines and capping them Start with the break booster. Sometimes the diaphram gets a leak in it and can be very hard to diagnose.

[cadence_1]

Yep, capped off brake booster, capped off all lines attatched to throttle body. Pressure tested directly at the throttle body. Haves pulled out all the butterfly crap. Only thing I can think is if the iacv is not functioning properly allowing idle to get crazy. But that doesn't souch explain the rich issue. So ok, I guess maybe I have a vac leak. But where? If it was bad enough to make the car run soooo rich, wouldn't I be able to hear it his under pressure? Maybe not? I don't know. But I am now getting very frustrated with this car.

[cadence_1]

at 1500 rpm you've got some sort of air leak..

using some smoothish vice grips (or brake line , block off the air supply to the idle control block by squashing the hose that feeds the idle control block.

If the car won't start or idle without the idle control block, then it's the idle control block causing problems..

The AAC will likely be stuck off it's seat from gunk and funk.

But it could also be the throttle is also gunked up, worn out, or adjusted open too far by some wangan racer..

Ok.. I want to start by apologizing. I must have been smoking some crack or something because the idle doesn't go up when I unplug the aac valve. It goes up when I plug it in. I have spent the last couple days cleaning things and checking them. I have tested the coolant temp sensor and it checks out. I have tested the air bypass valve and that also checks out. I have cleaned up a couple very small vacuum leaks as well(the brake booster isnt even hooked up at this point. I have capped the line off to minimize variables).

I started it again today, this time again with the maf attached as close to the TB as possible but with the idle air supply still hooked up. and it seems to run better as far as Air Fuel numbers. But it is still "idleing" at ~2200rpm. And when I unplug the aac solenoid, the idle will drop to 1500ish but air fuel witll also drop to 11.5's or so.

I tried clamping off the supply line as suggested, and the idle will drop to around 1500 again but air fuel is crap as well at that point.

I really don't understand how this can occur. As the maf should be reading a lesser amount of air mass coming in from the decrease in RPM and the air fuel should be adjusted accordingly? This is really bugging the crap out of me. I cannot count how many of these cars I have trouble shooted before (almost all were due to vac/boost leaks) and I cannot figure this car out for the life of me.

If anyone has anymore insight on what I can do I would appreciate it. I also tested the idle switching circuit as spelled out in the FSM and that seems to be functioning properly as well.

Even though I don't hear any hissing coming from them, could the injector seals be bad? The injectors were replaced(with original injectors that ran the car fine a year ago) and I had to reuse the old seals. I don't see why this would be a problem but I am open to anything at this point.

Sorry this was so long.

[fabio240]

Is your car turbo?

[sjbsuperman1425]

is it possible the adjusting screw on the bottom of the throttle body (underneath the pulley) is set to high?

[Myetball]

Take a piece of heater hose, a few feet, jam one end in your ear and probe around the intake manifold, injectors, all other gasketed areas and hoses. Often times you can't hear a vacuum leak just by leaning over the engine.

Another method, less reliable in my experience, is to get a can of carb cleaner with the little red tube attached and spray at possible leak points. If the idle settles down momentarily when you spray, you've hit the leak.

[cadence_1]

1. Yes the car is a CA18DET, so yes it is turbocharged.

2. I don't think the adjusting screw is messed up as this car used to idle fine. And the screw has not been messed with and isn't loose. I don't really want to start messing with the screw at this point as it just adds another variable into the equation. Is there a proper way to adjust the screw?

3. As far as taking a hose and listening. I imagine I could try that. But I would think the pressure testing that netted me no results would be a better test. If the leak was so small that I could not even hear it under 10psi of pressure would it have such a dramatic affect on on idle and air fuel?

4. And why is it that now I have fine air fuel ratios at 2200 but when I clamp the idle air hose off the rpms drop to 1500 and air fuel spikes? Can someone explain the workings of that? It is like the injectors are still injecting fuel for 2200 rpm but now its at 1500 and hence, rich?

I am about to give up and sell this damn car. Anybody else have any grand ideas. Please feel free to let me know.

Thanks as always.

[zero_gripS13]

not to thread jack, but im having same problem.

i did a boost leak test up to 20 psi, and found all my small leaks and fixed em i dont hear any hissing at the manifodl just air rushing inside it..

if i unplug my aav i cans et my idle to wherever i like but if i plug it in it goes to 1500 ish... my bov leak but i plug it to test and doesnt matter.. i pitch off the hose going from the "t" to the aav unit (one that behind the tb) and left the idle regulater unclamped and my car dies.... if i unplug the idle regulator nothing happends.. any ideaS??? if u want ill start my own thread just didnt want to cludder forum with same thread.

i did check ignition timing i unplug aav idle it to 850 and set it to 15btdc (but my cas isnt exactly centered it more to the counter clockwise a lil) any ideas on that?