Misfires at 3800rpm only

[Crab Spirits]

Misfires only at 3800rpm. Runs great any other time. Full throttle, idle, whatever. I have a bunch of sensors and stuff I can swap out to pinpoint, but I figured someone here might have experienced this and can point me in the right direction.

 

[rbruso]

Could be a bad spot on your TPS. Are you sitting in the car and slowly revving until the problem happens, or are you driving around with the car?

Just a thought.

 

[Crab Spirits]

This happens at any throttle position under load. Once you climb north of 3800, it runs normally.

 

[Off Road SHO]

Your computer also commands the solenoid on the back side of the runners to dump the vacuum that was holding the secondaries shut, at 3950 rpms. Might have something to do with it.

Tom

 

[mrecoolgar]

I agree with Tom.
Rpm's are just prior to the secondaries opening.