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Discussion Starter #1
Okay, so I have been having issues with a high idle at start up, really high. Yesterday I went to start it after double checking my firmware, and reloading my tune, and the instant it started it went to 4500 rpm before I could catch it. What happens is, it rev the crap out of its self untill I hit the gas, then it comes down.. Only does it when its cold, and after I hit the gas pedal, it doesn't try to rev way up.

Ive checked for intake leaks/redid intake twice, check for exhaust leaks, have tried a bunch of tunes, did datalogging, cleaned TB. Still does the same thing, currently Im waiting on a tune from VMP to see if that will fix it.

So I tried something this morning, I went out, turned the car on, didn't start it, but while the car was turned on, I pushed the gas about 1/8 throttle, then started it, and the thing worked.. It started, went to about 1700 rpm then feel down to 750 or so after 3 seconds.. no more revving..

So, Im just guessing here, but could I have a bad sensor somewheres in the TB? or maybe the spring in the TB is weak?? I don't know. But I find this strange being that once the TB moves, it doesn't try to rev up.

Any help on this would be great, Im kind of at a loss, but atleast Ive found something that has worked.. I know it still isn't right (shouldn't have to hit the gas before you start it).

Thank you all
 

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I would try that a couple more hundred times. It could of just been a fluke, a placebo if you will. I would wait to see if it does it with the tune from VMP Tuning. Have you replaced the TPS?
 

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sounds like the signal that the tps is sending to your ecm at startup is wrong...i would replace that and go from there. i haven't looked but it can't be too expensive.
 

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Discussion Starter #5
Nope haven't replaced the TPS or TB. Ill see what the tune from VMP does, and if that doesn't do it, Ill try replacing afew things.

Just strange.. I went back out this afternoon and tried it again, and it did work again..

The thing acts like it has a carb on it.. Seriously like you need to kick the choke off of it, if you start it, it revs, and you hit the gas and it comes down, just like kicking the high idle off of it. And if you hit the gas before you start it, it only goes to 1700, then right back down..


Thank you for your help.
 

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I had similar problems after putting in my E-Force. And...I fixed it.

Do this...with the car idling, go wiggle all the wires leading to your throttle body, including the TPS. If wiggling these makes your car do strange things like rev, increase idle speed, or decrease idle speed - then you've just got a bad harness.

Well the harness isn't bad, but its not pinching the wires very well which makes a poor connection.

So if this fits you, do what you have to do to make a more solid contact. PM me if needed and I could give you more tips.
 

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PM me anyway and I can send you some electrical debug steps from Ford which I used to narrow down my problem.
 

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Discussion Starter #9
Thank you!, Ill give this a shot when I get home today!
 
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