High idle at lower altitude or something else?
08-22-2011, 10:44 AM
#1
High idle at lower altitude or something else? I live in Fayetteville, AR which is 1400ft elevation (car was tuned at OKC, OK 1050ft-1300ft).
When I drive home to SE Oklahoma where the elevation is 450ft (but it is much more humid), the car often wants to idle high in gear and rolling. Once the car stops it takes about 20-30 seconds for the idle to drop to normal.
The car normally idles at 800-850 rpm. When it's acting up it idles at 1200-1500+ rpm which is enough to pull the car up on the brakes and the car will run up to 30mph with no throttle input. It does this in gear or in neutral. When the car is started it revs up and holds a 1000-1200rpm idle for about 10-15 seconds before dropping to 850rpm. Once you put it in gear the rpms start to climb.
I have read some about adjusting the throttle followers and crackers, but why would it do this there, but not once I'm back at the higher elevation? Shouldn't the car adjust itself for altitude?
I also cleaned the MAF, IAC, and the rest of the TB. Am I looking for the wrong problem or not?
When I drive home to SE Oklahoma where the elevation is 450ft (but it is much more humid), the car often wants to idle high in gear and rolling. Once the car stops it takes about 20-30 seconds for the idle to drop to normal.
The car normally idles at 800-850 rpm. When it's acting up it idles at 1200-1500+ rpm which is enough to pull the car up on the brakes and the car will run up to 30mph with no throttle input. It does this in gear or in neutral. When the car is started it revs up and holds a 1000-1200rpm idle for about 10-15 seconds before dropping to 850rpm. Once you put it in gear the rpms start to climb.
I have read some about adjusting the throttle followers and crackers, but why would it do this there, but not once I'm back at the higher elevation? Shouldn't the car adjust itself for altitude?
I also cleaned the MAF, IAC, and the rest of the TB. Am I looking for the wrong problem or not?
08-22-2011, 04:53 PM
#3
I will check that.
I did unhook the PCM from the battery to clean a terminal but it did not help. I am just a little confused as to why it started running properly again once I got back up here. It seems to do this pretty often I just paid more attention this trip because I was doing a rear disc swap and it was making it difficult to check the brakes when the engine was pulling against them.
I did unhook the PCM from the battery to clean a terminal but it did not help. I am just a little confused as to why it started running properly again once I got back up here. It seems to do this pretty often I just paid more attention this trip because I was doing a rear disc swap and it was making it difficult to check the brakes when the engine was pulling against them.
