'00 GTS, sometimes revs high at idle. Thoughts?

jdeft1

Enthusiast
Joined
Jul 9, 2008
Posts
2,401
Reaction score
1
Location
Metropolis
I'm thinking MAP or IAC but it's not my car and I haven't driven it. Seems fine while cold but starts idling up to 3k while warm... No CEL.. Apparently the high idle is intermittent. What is it???
 

dave6666

Enthusiast
Joined
Jul 18, 2007
Posts
14,975
Reaction score
0
Location
Explaining Viper things to you
Clean your IAC with throttle body cleaner then hose the inside with WD40. Drain the WD, then reinstall. It will take a few laps for the car to relearn. Meanwhile, grab an adult beverage and enjoy your accomplishment.
 

bluesrt

Enthusiast
Joined
Nov 17, 2008
Posts
5,011
Reaction score
3
you forgot to mention to hold the pedal to the floor till the pistons hit the spark plugs:drive:
 
OP
OP
jdeft1

jdeft1

Enthusiast
Joined
Jul 9, 2008
Posts
2,401
Reaction score
1
Location
Metropolis
I didn't quite get a feel for it .... I only had a short ride in it while we drove to the bank (a small transaction for some rims/tires)... The freaking thing was reving at idol. My spidy senses said MAP or IAC but I'm not a tech. I told him to swap the MAP ( it's cheap and easy...) and see what happens. Was I wrong?
 
Last edited:

Allan

Enthusiast
Joined
Mar 7, 2009
Posts
2,546
Reaction score
0
Location
La Junta Colorado 81050
MAP sensor will not cause high idle symptom.----straight up. I am a driveability tech ( for a living ) problem more likely to be TPS or IAC related. Here's an ugly truth we face everyday, not all driveability problems set a code. (most don't -that I see).
 

slitherv10

Enthusiast
Joined
Jan 23, 2012
Posts
517
Reaction score
0
I had an idol problem a month ago as well. Mine used to start fine and a few minutes later even at idol it would rev up and down. Not quite hitting 3000 rpm but would basicay have an irregualr idol. Up and down up and down. It ended up being the TBS sensor. My Tech unplugged my IAC and it was still doing it. As soon as he unplugged the TBS teh code reader read the idol fine. Process of illimination. Take it in to a guy who has the reader and it will save alot of thoughts and questions as well as headaches.

I think so anyways
 

Allan

Enthusiast
Joined
Mar 7, 2009
Posts
2,546
Reaction score
0
Location
La Junta Colorado 81050
F Y I, Chrysler IAC's for the most part, are very reliable. Occasional cleaning is not a bad idea though. Chrysler TPS's on the other hand, I've had to replace a few. (usually have a 'wandering voltage' condition that makes the idle erratic intermittently) On vehicles with automatic transmissions, you also get erratic shifting.--have seen this alot with "no codes".
 

Solid Red 98

Enthusiast
Joined
Oct 25, 2007
Posts
427
Reaction score
2
This may sound weird, but I tried all of the above, and it still came back intermittently. I also had periodic high temperature readings that didn't seem to make sense. Finally the temperature gauge need pegged and forced me to replace the temperature sender. The problem has not resurfaced in over a year of driving.
 

Allan

Enthusiast
Joined
Mar 7, 2009
Posts
2,546
Reaction score
0
Location
La Junta Colorado 81050
Wow, that's more of a rare case. Have seen it before, but not to often...False input of CTS temp high will cause high idle.-PCM stategy is to attempt to cool the motor down by spinning the water pump faster to increase coolant flow, radiator fan on high as well. Interesting how you figured that out. (they use the same sensor for the PCM input and the gauge input via multi-plexing) That's why the gauge reading high led you to fixing the idle concern. Lucky you!
 
Top