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Discussion Starter · #1 ·
My Bullitt has recently developed a fast idle. I have a canned tune on it and I am wondering if that might be the problem. The tune has been on it for several years and the only other mod is a cold air intake. Any ideas?
 

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Discussion Starter · #3 ·
No lights I wonder if I have a bad O2 sensor. I was going to try restoring the ECM back to stock to see if that did anything.
 

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Huh... Yeah I would definately try restoring the ECM. I think your programmer should read trouble codes. Bad sensors should trip the Service engine light... Again, I would check for vacuum leak just in case.
 

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O2 sensors aren't the culprit... I'd almost bet on an IAC going bad in some way.

Take it off, clean it and try again.

Mine does this from time to time... It's becoming more common on "older" Fords. :)
 

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Charles
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Bullitt664 said:
Huh... Yeah I would definately try restoring the ECM. I think your programmer should read trouble codes. Bad sensors should trip the Service engine light... Again, I would check for vacuum leak just in case.
I had one confirmed and but probably two bad front O2 sensors. I did finally get a code. Replaced them and the car ran like new. It had not run that well in a loooong time. That tells me the sensors were degraded for a long time before the code showed.

I think its probably the TPS or IAC.
 

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Discussion Starter · #7 ·
Thanks I will investigate this weekend. I have a 96 Ranger and for years it had a check engine light. I kept going to AutoZone and pulling the codes and replacing this and that including the O2 sensors. Finally took it to Ford and one of the replaced O2 sensors were bad. I bring this up because off and on it would idle fast.
 

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Discussion Starter · #8 ·
Well I restored my ECM back to stock on Sunday and the car is running normal again. I had that tune on it for years with not trouble so I am not sure what happened. I am going to put it back on after I drive the car for a while.
 

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Yeah strange it should give you trouble after so long... Oh well at least it was something "simple". Cheap fix too! Cool....
 
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