96 Trans Am WS6 T-Tops 81k.....CHEAP
11-05-2006, 05:26 PM
#21
Originally Posted by slick1851
***Now the bad: the car has a misfire from the 2000-3000 rpm range ONLY when it has warmed up. It runs PERFECTLY until it has reached operating temps. [U]
I had the same damn problem with my transam!!!!!!!!!!!!!!!!!
It pissed me off so much, I never could find out what it was either!
I had the same damn problem with my transam!!!!!!!!!!!!!!!!!
It pissed me off so much, I never could find out what it was either!
So, if the problem only happens in open loop, then obviously one of the sensors is failing. $10 says it is an o2 sensor or perhaps a MAF. Often those things will go bad and yet not set an SES light for another 500 miles or so. I had a misfire so bad that the car couldn't move out of its own way, and never showed a check engine light for it even though the o2 sensor was no longer reading anything!!
11-13-2006, 06:19 PM
#28
Launching!
Originally Posted by keliente
When the car first starts up, it is in open loop, which means it is running based off some predetermined values in the PCM. When it reaches operating temperature/etc, it is in open loop, which means that it starts taking readings from the other sensors into account.
So, if the problem only happens in open loop, then obviously one of the sensors is failing. $10 says it is an o2 sensor or perhaps a MAF. Often those things will go bad and yet not set an SES light for another 500 miles or so. I had a misfire so bad that the car couldn't move out of its own way, and never showed a check engine light for it even though the o2 sensor was no longer reading anything!!
So, if the problem only happens in open loop, then obviously one of the sensors is failing. $10 says it is an o2 sensor or perhaps a MAF. Often those things will go bad and yet not set an SES light for another 500 miles or so. I had a misfire so bad that the car couldn't move out of its own way, and never showed a check engine light for it even though the o2 sensor was no longer reading anything!!
