Idle Troubles

[Sanctus]

The question:

Does my car have the (05-22-8) WDS COP KIT DIAGNOSTIC TIPS-COIL ON PLUG (COP) IGNITION SYSTEMS-ENGINE MISFIRE OR ROUGH RUNNING TSB? Or is it another problem?

The Symptoms:

You know how upon startup the normal process is that the GT raises it's RPMs to about 1500 or so and then naturally dies down to around 800. Well about 3 weeks ago I noticed that the RPMs would hit that 1500RPM mark but then they would die down to around 4-500, sputter, and occasionally stall. The problem isn't quite as severe after it is warmer, but it's still noticable.

What I've done:

I went on ahead and filled the tank up with 91 and changed to the Bamachips 91 torque tune over the 87 perf tune hoping it was a problem or corruption of the tune somehow. But that yielded no change. I even modified the tune to have the idle at 740, 840, 940, and eventually over 1000. but the idle would always stay between 4-600 after each attempt. I thought it may have been a bad batch of gas but I have since ruled that out.

Other info:

As I mentioned before this came on kind of suddenly without any modifications or alterations to the vehicle durring the past 6months. I can't seem to figure it out. Do you guys think I should take it in? or just not worry about it? It doesn't seem too serious, but it just doesn't sound right when I first turn the car on. There doesn't seem to be a loss of power tho... So i don't think it is a misfiring cylinder but I could be wrong. One friend suggested it may be a vaccum seal leak of some sort? Any advice?


Thanks,

Sy

 

[Sanctus]

Nobody has any thoughts?

 

[tr7driver]

FWIW, You might try a new fuel filter

 

[shooterm1]

FWIW, You might try a new fuel filter

since it came on suddenly, it could be clogged injectors as well .... (bad Gas?)

 

[Sanctus]

Alright cool, that will give me some place to start at least.

Thanks guys. Any other ideas/suggestions are welcome and appreciated. It hasn't stalled this week, but it's come close around 500-600rpms a couple times. But I still think it is abnormal. I guess the next stop is the Ford Dealer

 

[sams66]

the irratic idle as other have called is pretty common. you may want to check out the TMS mustang website www.themustangsource.com as there is many discussions about it.

My 05 gt was in for it as well. never really repaired one of those "we couldnt get it to do it" issues. for me, it is pretty irregular and no particular driving style, time or anything brings it on. take it in to the dealer. many people have told me that it is the throttle position sensor or idle control sensor.

also, doug from Bamachips wrote a post about using throttle body cleaner to clean the throttle body and remedy the situation. i tried that and I still had the irractic idle.

good luck with yours.

Sam

 

[PoopDawg]

Did you try to put the STOCK tune back in to see if it was a tune problem?

 

[Sanctus]

Yes I put it back to stock, and tried the other two supplied tunes (on different batches of gas from different companies even) in an attempt to isolate the problem. But to no avail...

 

[billb60]

+1 on clean throttlebody. Had to do on mine and mom's Taurus. Both would stall out when coming to stop light. What happens is a carbon ring builds up in bore around the throttle blade, starving the engine of air when throttle is fully closed.

 

[Sanctus]

Update: So I took it into the dealership to get this and a set of squeeky brakes looked at. They glazed the pads and machined the rotors for me without asking. And then told me when I got there that they couldn't do anything about the engine codes the ECU was throwing because of the aftermarket intake and the increased ammount of air passing through the MAF. So they told me to put the stock airbox on and bring it back.


So I left with a 69.73 dollar bill, a mustang that occasionally stalls upon startup, and a set of brakes that still squeek.

If frustration solved anything my life would be in such good order right now.

 

[PoopDawg]

If you ever have a driveablility issue, they will always want the stock tune/airbox back in. Having an aftermarket intake/tune can cause these problems, and it's the first thing they would blame it on. Why would you bring it in with an aftermarket tune??? That's just asking for warranty problems. Be thankful they will even look at it now with the stock tune/intake back on.

 

[ski]

++1 on cleaning the TB.
Also, clean the MAF sensor.

 

[CPman]

I had a similar problem except my car would not stall. So I tried cleaning the thottle body at the area where the throttle blades seat when throttle is closed and found both the throttle body and blades to be extremely dirty with kind of a grimmy, gummy substance (not sure if this is the result of using a oiled air filter). I gently opened the throttle blades with my finger and clean this area with a lint free cloth sprayed with some carb cleaner. Started the car up and all my idle issues disappeared! I don't know if this will solve your problem, but for the 5 minutes it takes too do this, what do you have to loose in checking.

 

[Kilmar]

I had a similar problem when I had the JLT II CAI. I had installed it improperly and the intake tube wasn't fully connected with the TB or it could have been the air filter not clamped properly. Either way, I removed everything and reinstalled, making sure not to overtighten and voila, no more stall.

Of course, this was almost a year ago and the JLT II is no longer in my car...