Adjust TPS to fix throttle hang?

[w.neurauter]

I was just diong some searching and found this thread over at corral.
http://www.corral.net/forums/showthread.php?s=&threadid=286522&highlight=hanging+idle

Has anyone every tried this to fix the slow dropping rpms on our cars? I have tried the copper pipe mod but the side affects when it's cold out and the defroster are a killer.

I think I might give it a try. I always forget about it until I drive a friend's car and the revs drop quickly as they should. Thanks in advance for any input.

ford procedure is as follows:
1. get engine to operating tempurature. turn off ac, radio, etc.
2. disconnect IAC (idle air contol soleniod). if engine stalls turn throttle stop in one full turn and restart engine.
3. set throttle stop to desired idle speed (rpm)
4. set throttle position sensor anywhere from .96 to .99 volts. loosen the mounting screws and lightly rotate the sensor till the voltage is within range (use a mutimeter to check as your rotating). you may have to drill out the mounting holes to reach the desired range.
5. turn off engine. disconnect negative battery cable for 15-20 minutes. tap the breaks to ensure all capacitive power is lost.
this will reset the computer to factory defaults.
6. reconnect IAC. then connect battery cable.
7. restart engine and drive for about 15 minutes so the computer can relearn any settings that have been changed since factory.
8. if problem persists, inspect for mas air meter problems and possible vacuum leaks.
you may have to perform this procedure a couple times till the rev down is correct.
the first time i did this my engine would take about 7 seconds to rev down from 2000 rpm. this was due to the throttle position sensor being out of time(range). careful when tightening the screws back down because it will want to rotate in that direction.
also i was told that when you disconnect the solenoid harness and if the car dies, this is a dead give away that your throttle is not set right.
a quick check also is to turn the key to the on position but not starting the engine. then check your voltage on the tps.

 

[svtpower]

Hmm

Both my 99 GT and my 99 had this issue.

You can buy one of these http://cgi.ebay.com/ebaymotors/4-6-...006QQitemZ160065562748QQrdZ1QQsspagenameZWDVW

I just made one with some spare sheetmetal I had and it solved my problem.

 

[w.neurauter]

I've made the adapter out of sheet metal as well, it's really no different than the copper pipe mod. It just sucks when the a/c is on and the motor seems like it is struggling to keep up at idle. I've tried drilling a larger hole but then they don't drop quite as fast. This just looks like a better fix to the problem. I think I'll give it a try tonight. The 2 guys at coral that used it seemed to have pretty good results.

 

[hotpony]

Is this really necessary though? I drive a 96 Cobra and my idle doesn't hang at all, maybe running too rich?

 

[Tape]

svt, what side did you put the large hole and how does it idle with the a/c on?

 

[twogts4us]

Why is your idle hanging to begin with? Unless you've messed with the TPS already, it's likely at the desired setting now.

 

[w.neurauter]

As far as I know it is supposed to hang for a bit between shifts. Apparently ford programmed it into the ECU because it leads to better emissions. The best way from what I have heard to fix it is to re-flash the computer with a programmer. I was just trying to save myself some cash and eliminate it for free.

I've tried taking it in under warranty and all the techs tell me that it is supposed to hang for a few seconds before dropping in between shifts. It's just annoying because it takes forever to shift and can't be good for the clutch.

I'll report back if it works. It's just an annoying problem that really bugs me whenever I drive another car that doesn't do this.

 

[svtpower]

no idea

I can't really comment on with A/C on, because I have never once used the A/C in the Cobra. I always drive with the windows down cause I love the exhaust note. And if it's super hot out I ride my cycle.

My GT had the hanging RPMs before and after my diablosport chip, the Cobra only did it after I got a custom tune via my Predator.

All good now though...

 

[thomas91169]

i never minded the shift-hang, but after i installed the diablo provided tune in the Predator, it got rid of the shift hang.

 

[Mike97gt]

You can try it but I do not recomend this.. the way our TPS works this should have almost no effect since idle is relearned everytime the car is started.. the PCM just takes the lowest TPS reading and assumes thats closed throttle.. anything from .53-1.27 is within range.


You can adjust the dashpot setting in the tune to fix this "problem" the right way.