My Car has a Mind of It's OWN!

[7upstang91]

My car has idle issues now it idles way to high. On top of the when I push the clutch in the RPM's scream way to high. It seems as if the throttle is stuck. I have to down shift to drop the RPMs. When going down a road it will drive at 50mph(in 5th gear with 3.73s) with my feet away from the pedals, I am NOT touching the pedals at all. When I come to a stop I have to turn my car off to avoid of revving. I have no clue what the problem is. This is the second time it has gone to the shop in two days. Help please! I did put on a new distributer.

Thank you!

 

[tannerc91gt]

I'd go through the idle check list, the rest is pretty weird but check the tps

 

[time only]

Might want to take a close look at the throttle cable linkage. Start from the throttle body first.

 

[7upstang91]

None of this happened until the car died last thursday when I came to a stop. It just now started doing it when I replaced the distributer. Thank you I will check it tommorow.

 

[Nicoleb3x3]

When you lose power the computer must "relearn" how to idle properly.
you say the car almost revs itself...to what RPM?

I JUST went through this myself, car would drive down the road at 1500 rpm without any throttle in 4th gear at 45-50 mph cruising speed. Sometimes when shifting to reverse it would rev up to 2200 rpm! then slowly come back down again...to like 1200! At start up it would rev to 2500 rpm and slowly come down to 1200...ish.

I think it can take up to 100 miles for the computer to go through enough stop/go and start ups to figure out what is best for idle. Let the computer re-learn by itself if you didn't have trouble before- BUT; I would make sure you throttle cable isnt obstructed first!

you can always resent your idle...check stangnet has that proceedure somewhere- or; do what i do...just turn the idle screw on the throttle body and see if you can get it happy sooner (that's what I did, I had set a specially high idle at 1000 rpm after my rebuild which was before I got a tune for my new cam) I got a tune now but never fixed the idle before my battery ground came loose and my computer lost power long enough to lose it's memory, so it has to relearn again the idle settings...so after 100 miles my computer could only get a 1100-1500 rpm idle which totally sucked!...so then I just turned the idle screw back down to match what it should have been from the start)

I'm now idling at 900 rpm...which is ok for my cam! lower I might have issues running my alternator with underdrive pullies anyways.

 

[tannerc91gt]

When you have disconnected the battery, start the car and let it idle for 5-10 minutes, that allows time for it to relearn idle, no need to drive 100 miles, and yea the car will act all whacked out if you don't allow the ECU to relearn idle

 

[Nicoleb3x3]

Ford says...100 miles before it's perfect- probably depends on how long you let it idle the first time..and if you run accessories etc etc

100 miles MIGHT be nessasary in those cases; how many poeple actually keep the radio off when they first start the car?

 

[Nicoleb3x3]

oh yeah, and the odds they let the car idle a full 10 mins without accessories before driving off = slim
that's where the 100 miles comes in...

...or reset the battery again and do it right

 

[Celeb]

+1 for tps did you pull out the spout connector when you replaced the distributor?

 

[2000xp8]

I agree with checking the tps.
I had a similar issue way back.

As far as driving it 100 miles. I'm not buying into that.
My buddy owns a shop and i've been there plenty of times for cars that have been apart for months even years (including mine) and each time if the car was reassembled properly, the cars start and run perfect, including the idle.
They really don't need to relearn how to idle.

 

[Celeb]

if you loosen the screws for the tps, even though it only moves a little, if you have the engine running and move it, you'll notice it will greatly increase or decrease the idle rpm. Check for less than 1.0 volt at idle (.98 to .99 Volts range)

 

[HISSIN50]

What codes are stored?

What happens when you restart the car? If it idles ok for a little while and then acts up again, put a spare TPS in the car.

Make sure you don't have any massive vac leaks.
See if it has a normal (non-sticking) hot idle with the IAC electrical connector disconnected (don't drive it like this - just see how it idles).

As far as moving the TPS and having the idle go up and down from that alone, that should not happen, nor would it be a permanent means of adjusting the idle. The ratch function baselines the reading continuously.

 

[jrichker]

See the "Surging Idle Checklist for help with all your idle/stall problems. Everything you need to find and fix idle problems is in there.

The first two posts contain all the updates to the fixes. At last count there were 24 possible causes and fixes for surging idle/stall problems. I continue to update it as more people post fixes or ask questions.

 

[7upstang91]

Ok I figured it out. The set screw on my throttle body was spinning and then stopped when the RPM's were high. I reset it and made sure it was in place. Ran it slow, then hard, the normal for several miles. No problems.

 

[time only]

Glad you did..