Help diagnose whats wrong with my car.

*madmatt* · 09-02-2006, 09:20 PM

Ok, so heres the symptoms...

Once the car warms up, the rpm seem to hang when coming to a stop with the clutch pushed in.

If you come to a complete stop, sometimes theyll fall back down, but slowly, and hanging, much like what happens with an aftermarket plenum/tb setup, only I dont have one.

I thought it could be something I messed up putting in the clutch, but it only does it AFTER the car is warmed up, so Im thinking its a sensor under the hood. Just wondering if any of you have had this happen before. Dont think its the IAC cause the car will hold an idle, just very high. Let me know what you guys think. Thanks

Matt

MattJ · 09-03-2006, 01:14 AM

check the voltage of it. it should be between .98 and 1.0.

*madmatt* · 09-03-2006, 06:32 AM

Of the tps?

MattJ · 09-03-2006, 06:46 AM

Quote:

Originally Posted by madmatt

Of the tps?

Yep.

dom · 09-03-2006, 08:02 AM

it happens sometimes with plenum and TB installs. i just get lucky most of the time

*madmatt* · 09-03-2006, 10:38 AM

But I dont have a tb/plenum, and the tps was set when we put the stock stuff back on to around 1.00. Maybe the tps itself is bad?

r3dn3ck · 09-03-2006, 12:11 PM

could be a sticky IAC.. it doesn't have to fail to give strange idle quality. It just has to be a little grimy to fail to close properly.

I think you can safely rule out a vacuum leak if it doesn't stumble while idling at a stop.

*madmatt* · 09-03-2006, 12:57 PM

Yea, I may pull that off and spray it down. I just replaced the damn thing like 8k miles ago. I need a new pcv valve too.

stage2roush2002 · 09-04-2006, 10:03 AM

Quote:

Originally Posted by r3dn3ck

could be a sticky IAC.. it doesn't have to fail to give strange idle quality. It just has to be a little grimy to fail to close properly.

I think you can safely rule out a vacuum leak if it doesn't stumble while idling at a stop.

Thats what mine was....I thought it was the tb/plenum but it was the IAC

*madmatt* · 09-04-2006, 10:33 AM

Ill give it a good spritz with some brake cleaner. Thanks guys. Ill let you know if it fixes it.

09-02-2006, 09:20 PM	#1 (permalink)
madmatt Traitor...lol Join Date: Sep 2004 Location: Lexington, SC Posts: 7,929	Help diagnose whats wrong with my car. Ok, so heres the symptoms... Once the car warms up, the rpm seem to hang when coming to a stop with the clutch pushed in. If you come to a complete stop, sometimes theyll fall back down, but slowly, and hanging, much like what happens with an aftermarket plenum/tb setup, only I dont have one. I thought it could be something I messed up putting in the clutch, but it only does it AFTER the car is warmed up, so Im thinking its a sensor under the hood. Just wondering if any of you have had this happen before. Dont think its the IAC cause the car will hold an idle, just very high. Let me know what you guys think. Thanks Matt __________________ RPMPlanets

09-03-2006, 01:14 AM	#2 (permalink)
MattJ Senior Member Join Date: Dec 2004 Location: Racine, WI Posts: 10,243	check the voltage of it. it should be between .98 and 1.0. __________________ 2001 Mustang GT Premium - Mineral Grey

09-03-2006, 06:32 AM	#3 (permalink)
madmatt Traitor...lol Join Date: Sep 2004 Location: Lexington, SC Posts: 7,929	Of the tps? __________________ RPMPlanets

09-03-2006, 08:02 AM	#5 (permalink)
dom whos gonna ban me next? Join Date: Apr 2005 Location: baltimore, MD Posts: 1,268	it happens sometimes with plenum and TB installs. i just get lucky most of the time __________________ 2007 explorer limited procharged 2002gt sold new project: 427w c4 9" fox

09-03-2006, 10:38 AM	#6 (permalink)
madmatt Traitor...lol Join Date: Sep 2004 Location: Lexington, SC Posts: 7,929	But I dont have a tb/plenum, and the tps was set when we put the stock stuff back on to around 1.00. Maybe the tps itself is bad? __________________ RPMPlanets

09-03-2006, 12:11 PM	#7 (permalink)
r3dn3ck Wowbagger hates me too! Join Date: Nov 2005 Location: Magrathea/California Posts: 7,018	could be a sticky IAC.. it doesn't have to fail to give strange idle quality. It just has to be a little grimy to fail to close properly. I think you can safely rule out a vacuum leak if it doesn't stumble while idling at a stop.

09-03-2006, 12:57 PM	#8 (permalink)
madmatt Traitor...lol Join Date: Sep 2004 Location: Lexington, SC Posts: 7,929	Yea, I may pull that off and spray it down. I just replaced the damn thing like 8k miles ago. I need a new pcv valve too. __________________ RPMPlanets

09-04-2006, 10:33 AM	#10 (permalink)
madmatt Traitor...lol Join Date: Sep 2004 Location: Lexington, SC Posts: 7,929	Ill give it a good spritz with some brake cleaner. Thanks guys. Ill let you know if it fixes it. __________________ RPMPlanets

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