4g63 idle problems

[tubbedtalon93]

I got a 93 talon with the 4g63. when the motors cold it idles to about 2900rpm and drops to 1000rpm continuously until it warms up. I have an air fuel gauge hooked up , and it jumps up and down while i'm cruising along. when i let out the gas it drops pass lean and backfires a little. Someone told me it might be the mas, but i wanted a pro opinion.

 

[92AWDHX40]

Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)
start here. check cels if any.

 

[GRAVEDIGGER]

Sounds like normal operation to me. When the car is cold it should idle high and gradually come down lower as it warms up. The air/fuel guage will show a flutter, or back and forth reading when it is cruising with light to mid throttle and under idle conditions. The only time it will become steady is with a full throttle application and under decel it will read full lean... This is all normal.

 

[tubbedtalon93]

Thanks for the link. But i just replaced all my sensors except mass air when i rebuilt the motor. It only does it when its COLD, and when it warms up it runs fine. Except for the air fuel gauge riches out when i heavy throttle it and leans out when i let off.

It dosent just idle high it surges constantly untill it warms up, and then it runs fine.

Sounds like normal operation to me. When the car is cold it should idle high and gradually come down lower as it warms up. The air/fuel guage will show a flutter, or back and forth reading when it is cruising with light to mid throttle and under idle conditions. The only time it will become steady is with a full throttle application and under decel it will read full lean... This is all normal.

 

[slayer450]

Sounds like normal operation to me. When the car is cold it should idle high and gradually come down lower as it warms up. The air/fuel guage will show a flutter, or back and forth reading when it is cruising with light to mid throttle and under idle conditions. The only time it will become steady is with a full throttle application and under decel it will read full lean... This is all normal.

Yes it should idle high at start up but 2900 is a little much, 1500 max. I say check for a boost leak and make sure tps is adjusted right.

 

[tubbedtalon93]

Haha its non turbo, i will try and post a video to show what its doing.

 

[DSM1G90]

ISC and BISS out of adjustment.

1G BISS Adjustment

 

[slayer450]

Haha its non turbo, i will try and post a video to show what its doing.

Then check for vacuum leaks.

 

[Rsawd95dsm]

Its your BISS or the throttle body might need a rebuild