Weird HANGING IDLE problem, not the usual one! HELP

[91LX_5L]

Ok I know all about the hanging idle problem, I still have yet to check my TPS. I adjusted the screw on my throttle body and lowered my timing a bit which did help a lot.

When im driving around and shift at like 2,700 or above when I put in the clutch my RPMS shoot up about 500rpm or mabye a bit more untill i get in it gear again then it drops right down. When I come to stop signs it sits at like 1,000rpm then goes down to 800 or so.

Ok the weird part that confuses me. I noticed it seems to hang up around 1,000 after I put it in neutral when im stoping at a light as soon as I put in the clutch to put it into Neutral it goes to 1,000+ and sits there, but I noticed IT SITS THERE UNTILL I COME TO A COMPLETE STOP then like 3 seconds later it drops down. SOOO I tested it, I went to a long hill, crusing in 3rd I put her in neutral, the rpms go down but still hang at 1,000 like usual, I coast for a good 15 seconds but there still haning, come to the stop sign then 3 seconds or so later they drop down.

DOES THAT SOUND LIKE A NORMAL HANING IDLE PROBLEM? What could this be!!?

ps: I have H/C/I, TB, and all the usual boltons.

 

[91LX_5L]

anyone!?

 

[mo_dingo]

My car does the same exact thing yours is doing. I will give you a little background on my car so maybe it will help yours.

I removed my IAC valve to clean it. Soaked it in carb cleaner for an hour or so. When I put it back on, my new idle speed was 2500 rpm's. Wouldn't go any lower.

The carb cleaner broke my IAC valve.

Long story short, I replaced my IAC valve w/ the wrong one from autozone, and I kept searching for the solution. I turned the throttle blade stop screw down more, to lower my idle. I also turned the alan head screw on top of the TB all the way in to lower my idle speed.

So, once I figured out that AUTOZONE SUCKS, and sold me the wrong part, I got the correct IAC valve, and my extremely high idle problem was solved.

But after that, the hanging idle, exactly like you are experiencing, started to happen.

I know I need to reset my idle back to factory specs, because I screwed it up big by messing with the throttle blade screw and the alan head screw.

So far I put the throttle blade screw back to normal. But I haven't done the rest to get it back to 100%. I suggest you reset your idle accoring to factory specs, and see what happens.

Hopefully you have a chip or tweecer to manage the h/c/i, or don't have a nasty cam.

Here is a link to how to set your idle correctly.
Scott

 

[91LX_5L]

yea i think i had it fine but then i messed with my screws and it went like this (adjusted my throttle body screw, then the idle alen key screw) i dunno if i just have to rest my computer or what

 

[91LX_5L]

ttt

 

[Jerm95gt]

yea i have had the same problems. ok the best thing i did that gave the best results was this, instead of playing with that allen wrench air idle adjuster screw so much just make sure its opened enuff to get air, but not too much. Then use the screw on the TB that physically moves the idle up and down by pushing the throttle. play with it until you get it worked out (reset the batt in between) then let it idle for a few minutes once you get it working. After that it should be some what better. Remember you want to raise the idle using the screw on the TB.

 

[BlackVert]

i had the exact same symptoms on my 1996 and it turned out to be the idle air control valve was sticking open. as soon as i replaced it ($45 at autozone), the problem was completely solved.

 

[Slow5.0]

I have exactly same problem, I tyed close that screw at IAC but nothing

 

[mo_dingo]

I just fixed my hangine idle problem. I used the instructions from the link I posted above, and now everything is great!!
Scott

 

[GTJake]

My car did the exact same thing when I first swapped to the fox style TB. I was assuming it was because I was using a 15 year old stock TPS sensor. Got my new TB with a new sensor and the hanging is gone.

Jake

 

[Slow5.0]

I just fixed my hangine idle problem. I used the instructions from the link I posted above, and now everything is great!!
Scott

I just fixed my idle from that post you posted mo dingo

Thanks man

 

[Project 77]

My car is doing the EXACT same thing but I have an X cam...I'm going to try these fixes but is there anything else i should do because of the Cam?

 

[mo_dingo]

I just fixed my idle from that post you posted mo dingo

Thanks man

Good to hear Ernie. It was getting on my nerves!

My car is doing the EXACT same thing but I have an X cam...I'm going to try these fixes but is there anything else i should do because of the Cam?

Since you need to raise you idle speed more than us non cammers, I would suggest replacing the TB stop screw with a longer screw, but with a hex head. That way you can easily adjust it w/o screwing up the threads w/ pliers.

Follow the link that I posted above. For you, I would disconnect the IAC connector, start the car, tighten the TB stop screw until you reach 900 rpm's or wherever you need to be, then turn off the car. Reconnect the IAC plug, disconnect the battery to reset the comp, reconnect battery, tighten the the IAC adjustment screw on top of the TB until it's completely closed. Then loosen the IAC screw exactly 1 & 1/2 turns, then start the car. The car may or may not stall. If it stalls, you need to tighten the TB stop screw 1 full turn, and try it again. Tighten the TB stop screw until it stops stalling & idles at the correct rpm's.

From my experience, the IAC screw needs to be under 2 turns to remove the hanging idle plague that we experience. That is what cured my hanging idle problem.

But since you need a higher idle speed, screwing the TB stop screw too much will make the car will not decelerate as fast as it used to, because the TB is open slightly more when you let off the gas completely.

Until you get a custom chip, or a tweecer, I can't think of anything else you can do.

Maybe someone here can in your situation can comment further or give some insight.

Scott

 

[red94fiveo]

Aha! My car has done the exact same thing ever since the H/C/I swap, I mean exactly as you have described. I've had other problems to worry about, so I haven't got the this one, I always assumed it was related to the swap anyway.

 

[Project 77]

Thanks for the advice...will this problem cause por gas mielage? FOr some reason my mileage has completly gone in the toilet.