Whoa!! I gotta bad idle now, whats it sound like to you?

[Kdubslugga]

In the past 3 or 4 days my car is idling awful. It always idled bad when i first started it up then after like 30 seconds it was fine! After about a minute it starts to idle good now, but that only if its in Neutral or Park, if its in D or R it idles horrible it goes to 1200rpm drops to 500rpm then it shoots back up to 1200 and back down again, sometime it even stalls on me. I checked under the hood for any vacuum leaks and the IAC gasket is shot and i was hearing a real high pitched squeel! Could this be the problem? I wouldnt think that would cause that big of a idle jump. Need some suggestions here, what should be some other things to check?

 

[ECU5.0]

that iac gasket is probably the problem....its letting too much air into the engine. also check the tps voltage, could be something with the trans...but im not sure

 

[Kdubslugga]

that iac gasket is probably the problem....its letting too much air into the engine. also check the tps voltage, could be something with the trans...but im not sure

Yeah im definetly gonna replace that gasket but where is the tps voltage thing? How do i check it?

 

[ECU5.0]

pm jrickter....i think thats his name. he has websites that show how to do it

 

[Kdubslugga]

will do thanks ECU

 

[Kdubslugga]

ahh it said he isnt a registered user

 

[jrichker]

As requested...

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host)

idle speed: http://forums.stangnet.com/attachment.php?attachmentid=23969

TPs location: http://www.veryuseful.com/mustang/tech/engine/images/TPS_IAB_Pic.jpg

http://www.veryuseful.com/mustang/tech/engine/

Here’s a TPS tip I got from NoGo50…

When you installed the sensor make sure you place it on the peg right and then tighten it down properly. Loosen the back screw a tiny bit so the sensor can pivot and loosen the front screw enough so you can move it just a little in very small increments. I wouldn’t try to adjust it using marks. Set it at .80v-.99v, Just don’t go over .99, or you’ll upset the fuel calibration and idle quality may suffer, along with some other problems like poor gas mileage.


(copied from MustangMax, Glendale AZ)

1. Always adjust the TPS and Idle with the engine at operating temp. Drive it around for a bit if you can and get it nice and warm.

2. When you probe the leads of the TPS, do not use an engine ground, put the ground probe into the lead of the TPS. You should be connecting both meter probes to the TPS and not one to the TPS and the other to ground. Use Green & Black wires for your measurements.

3. Always reset the computer whenever you adjust the TPS or clean/change any sensors. I just pull the battery lead for 10 minutes.

4. Check the procedure for your year, on my 90 I have to turn the idle screw until it just touches the tab, then insert a .010 feeler gauge and give it about one more turn. Then you adjust the TPS voltage to .80v-.98v, reset the computer. Start it up, if the idle is to low then turn the screw in until it is just right, then readjust the TPS voltage to .80v-.98v and reset the computer and start it up. The key is to adjust the TPS voltage and reset the computer whenever the idle screw is changed.

 

[demonspeedshop]

I had the same problem last year with my car. Try cleaning out all the parts in the region of the throttle body including the throttle body. If they're really dirty change the gaskets too. That was all it took on my car but the other stuff I've seen in this thread makes sense too.