Probles With IDLE !

[DanmMh]

what zup, so i have the same problem, when i have the car on, the RPM goes down to 800 and i dont know why it goes alittle bit up around 1000 and then down, or goes down to 500, and sometimes a feels like it wants to turn off, I Clean the MAF, Throttle Body and the IAC, and still the sameeeee GRR ! you guys think it could be the TPS ? ? or a VACUUM leak ? ? Im in san diego and i need a good mechanic to help me find this problem, does any body knows one ?

THANKS

 

[wmburns]

When was the last time the PCV value was replaced? Are all of the vacuum line leak free and in good shape? No rot, dry or brittle?

For more information on how to trouble shoot IAC issues, check out:
Is your mustang stumbling, dieing at idle or idling rough? - Page 14 - Ford Mustang Forums

 

[DanmMh]

The Hoses look on a Ok condition, I inspect them all and they seems to be ok, and the PCV valve i bought it but i could not find it hehehe so i did not replaced it, can somebody show me how to replace it ? or where is it located ? or a link on how to change it ? so, you dont think it would be the TPS ?

 

[wmburns]

Might be handy to know the model year of your car.

Did you read the information in the link? If so, you would know that this problem could be a vacuum leak, bad TPS, bad IAC, loose or worn TB linkage, bad or missing throttle return spring. The post gives information on how to narrow it down.

Seems very silly to me to have a PCV valve of unknown age and not replace it.

The TPS question is easily answered by monitoring the TP-MODE PID for a value of "C/T" whenever the throttle is closed. The TP-MODE should go to "P/T" whenever the throttle is depressed. If not, suspect a TPS problem.

The attached picture is from the V6 97 MY. For the V8 SOHC, the PCV valve is on the top center right hand valve cover. The 2001+ uses a high interference fit that has a 90 degree turn to remove.

 

[DanmMh]

yeah i Red it , its a 2000 Mustang GT, Manual with 96K , i dont know this it a small issue but hard to troubleshoot, it could be a lot of things !i was reading on the link that you gave me that It could be the coil packs , ii started it doing the basic and ill have to keep moving foward until i find the probleM! ! ! GRRRRRRRR..... =(

 

[DanmMh]

I did the test, i Disconected the Electrical cable of the IAC and the engine shut down, i guess it will be a vacuum leak, ill take it tomorrow to do a vacuum test and ill see what the results are... or ill change the TPS sensor and see if it gets better. Thanks =D

 

[wmburns]

If you are going to revert to "parts changing", IMO it makes far more sense to replace the IAC. Since you stated the IAC was cleaned and the 2000 GT has a black vented IAC, there is one possible issue.

The black vented IAC has internal valves that need to close off the vent when the motor runs. Cleaning damages these vents which trades one problem for another.

A bad TPS is usually associated with a high idle.

Your reported symptom is idle "hunting". This is usually associated with a bad IAC, bad PCV valve, or loose TB linkage. The basic IAC functionally test indicates the IAC is working at some level.

Just to be sure, confirm that the cooling fans work on both speeds.

But the facts are that IAC's fail at a fairly high rate. So if the other usual causes have been partially ruled out, changing the IAC is not a bad plan of attack.

 

[Doomedfailure]

I had a similar issue with my stang about 3 months ago I figured it was a vacuum leak. Anyways I did not find anything but I recently did a tune up new plugs wires and coils since they were old. And the problem was gone.

 

[DanmMh]

How much did you pay for all the parts for the tune up ? ? and did you buy only the coil wires and plugs ? or something else ?

 

[BraggStang]

Seems like your IAC Is bad. I had the same problem. My car would idle normal with the AC off and when I put a load when the AC was turned on it would die. I replaced the IAC and it corrected the problem. Go to Auto Zone and order one for 63 bucks.