Rough Idle on startup, Rich exhaust, warms up and then all is well...?
06-27-2007, 05:31 AM
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Rough Idle on startup, Rich exhaust, warms up and then all is well...?
Any BTDT's for the following?
93 S4 with 109K on the clock. Start up on cold, either overnight or after a day of sitting the parking garage at work. Runs rough like on 4 cyl and strong unburnt fuel smell from exhaust. Let it idle like that for 5 minutes maybe and something changes and it idles fine, runs fine. My thoughts are obviously it is temp related but what? Coolant? Oil? I really think coolant related but I don't know of a sensor that would read either coolant or oil temp and feed that info to the ECU to tell it to run rough like that when cold. Am I looking at another Multi Function Coolant Temp switch under the intake replacement?
Just want to narrow down my "buy a switch and replace" repair bill. I know I could run all kinds of temp and ohm readings from various spots but really don't have that kind of time or money for the indy to spend that time under the hood with all the probes.
Thanks
93 S4 with 109K on the clock. Start up on cold, either overnight or after a day of sitting the parking garage at work. Runs rough like on 4 cyl and strong unburnt fuel smell from exhaust. Let it idle like that for 5 minutes maybe and something changes and it idles fine, runs fine. My thoughts are obviously it is temp related but what? Coolant? Oil? I really think coolant related but I don't know of a sensor that would read either coolant or oil temp and feed that info to the ECU to tell it to run rough like that when cold. Am I looking at another Multi Function Coolant Temp switch under the intake replacement?
Just want to narrow down my "buy a switch and replace" repair bill. I know I could run all kinds of temp and ohm readings from various spots but really don't have that kind of time or money for the indy to spend that time under the hood with all the probes.
Thanks
06-27-2007, 06:43 AM
#3
Dude, you need to check out the FAQ. The info you need is there. (Link to exact info inside)
<ul><li><a href="https://forums.audiworld.com/s4s6/msgs/150040.phtml">G62 coolant temp and MFTS info link(s)</a></li></ul>
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