misfire?
Melting Slicks
Joined: Sep 2005
Posts: 3,082
Likes: 0
From: eagle mountain utah
The difference between open and closed loop is the front O2 sensors. I'd look at what the O2 readings are on a scanner when the rpms drop. Also, if you have a wideband AF gauge, what is it showing?
What is timing doing when the rpms drop?
What is timing doing when the rpms drop?
Last edited by leojnknsC5; Apr 29, 2008 at 06:08 PM.
Melting Slicks
Joined: Sep 2005
Posts: 3,082
Likes: 0
From: eagle mountain utah
Its possible that the drop is caused by the Throttle Positioning Sensor or TPS. The computer adjusts timing and throttle position to arrive at an operating idle rpm. The throttle is moving open and closed to maintain engine rpm. If it doesnt cause any other problems, ignore it.
Make sure your BOV boost outlet valve is operating like it should. A bad BOV will wear out a throttle body pretty quick.
Make sure your BOV boost outlet valve is operating like it should. A bad BOV will wear out a throttle body pretty quick.
Le Mans Master
Joined: Aug 2003
Posts: 9,298
Likes: 4
From: American Canyon Lethal Injection
Hi Lucky,
Today I went back to my installer/tuner Robert at Advanced Dyno here in NorCal. (great shop and a great guy)
He got my misfire out by taking out timing. I'm running 14* of timing and that seems to have taken care of the misfire of 100 RPM. My idle is at 650/675 RPM. It idles great for the A4.
This may help your situation.
Good luck
Thanks for all the input on this issue.
SleeperC5
Today I went back to my installer/tuner Robert at Advanced Dyno here in NorCal. (great shop and a great guy)
He got my misfire out by taking out timing. I'm running 14* of timing and that seems to have taken care of the misfire of 100 RPM. My idle is at 650/675 RPM. It idles great for the A4.
This may help your situation.
Good luck
Thanks for all the input on this issue.
SleeperC5
