im gona hang myself

[88mustangGT]

well this is geting really anoying. it all started after i put my lower ported on.

today my rpm would hang at 2500 it would pull the car to that rpm while driving. so i pulled over and moved the trottle body cable thingy to see if it was just stuck but it wasnt. i unhooked my iab and tps and it didnt do any thing so i had to just drive it the rest of the way to school.

what finaly made it stop sticking at 2500 was wot for a few gears.

my idel doesnt drop to 800 till i come to a compleat stop while im movign its at 1100 or so.

what is causeing this? is it the tps or iab or somthing else?

thanks.

 

[dastang2]

tps

 

[CobraWannabe]

I think the idle always does that on fuel injected Stangs. Did you disconnect your battery? Maybe the computer needed to relearn everything.

 

[88mustangGT]

yup i have tryed adjusting the tps and disconected the battery overnight. i couldnt get the volts high enogh if i remember right the highest i could get it was .7

 

[jerry beach]

Is your engine stock otherwise?

It all started when you put on the ported lower, or after you had driven it for a few miles?

Hook a vacuum guage to it, sounds to me like you have created a vac leak. Did you torque the bolts in sequential steps? check the torque on them again.

 

[noslow5_0]

mine will hang at 1100 while driving, then drop to 750-800 when stopped.... i think thats just how it is....

 

[88mustangGT]

ive found all the vacume leacks and i did do the cris cross tightening of the lower.

but it doesnt hang all the time it happens whenever it wants to. thats whats throwing me off.

 

[CManT1914]

The idle hanging is normail. When I push in the clutch and am coasting to a stop, it always hangs at about 900 rpms. When I stop, it goes down to 650 or so.

 

[88mustangGT]

im talkin like 2k

 

[L8 MUSL]

The idle hanging is normail. When I push in the clutch and am coasting to a stop, it always hangs at about 900 rpms. When I stop, it goes down to 650 or so.

No, it's not.
And, 650rpm is too low.
sounds like TPS is wrong or perhaps you need to clean your IAC.

 

[CManT1914]

No, it's not.
And, 650rpm is too low.
sounds like TPS is wrong or perhaps you need to clean your IAC.

Then how come everybody else in here has a hanging idle too? I always thought 650 seemed like a low idle, but I checked with Ford and they said it was nothing. 2k is a high rpm for it to hang at, but I'm talking about like 900 or so.

 

[L8 MUSL]

Then how come everybody else in here has a hanging idle too? I always thought 650 seemed like a low idle, but I checked with Ford and they said it was nothing. 2k is a high rpm for it to hang at, but I'm talking about like 900 or so.

By "everybody else in here" I guess you mean everybody in THIS thred.
Mine doesn't "hang".
I set my idle at 900rpm.

 

[willys1]

when mine is warm,and in gear,its at 650

 

[ComfortablyNumb]

Drill one of the screw holes in the TPS a little larger so you can rotate it more and set it between .97 and .99 Volts. My car used to hang around 2000rpm too and it turned out the intake seals were bad, so you may be leaking air in through an intake gasket or something.

 

[Idwitheld-1`]

The problem is NOT your tps.

You probably have unmetered air entering the motor.

I had a vac leak in a vac hose under the upper plenum. It was cracked and the idle would swing between 400 and 1500. It all depended on the hose. If I touched the hose, it would jump to 1500, let go and it falls to 400. Damn hose would leak based on vibration and temperature...I swear I set the idle a dozen times but it was all dependent on the condition of the hose.

Pulled a few hairs out on that one. Also, check the PCV hose and make sure its in good.

 

[88mustangGT]

ill recheck my hoses, what one was it, the one in the front? cause i would suspect that one for me if its any of them.

when you say leaking air i take it this is between the upper and lower?

 

[HISSIN50]

for the record, if not already stated, i believe the stock idle setting was 652 RPM.

as ID said, really check the vac lines under the plenum (upper intake). they really get toasted. you should have 15-20 inches of vac at idle. did you use a new gasket on the plenum to lower intake?

good luck.

 

[88mustangGT]

no i didnt, it is the same felpro one that has been on there sense i got the car, the upper has came on and off more times than i could count without a problem.

 

[88mustangGT]

ok if there is un metered air geting into the system ie threw a vac leack or seal between upper and lower, that would just cause it hanging at like 1100 before car comes to a stop rigght? i dont see how that would cause it to idel at 2 or 3k and just stick there. if anything it would make the idel more loopy and less smooth.

 

[sublime29]

Get some throttle body cleaner and start spraying all areas that could cause a leak.All vacuum lines around upper and lower intakes.I mean every where and listen for a idle chamge and if you hear one that is one of your leaks.