I have been having a weird issue with my RPM's lately. When I hold the car at a specific RPM in neutral the RPM will jump up and down about 500rpms. When I drive it and hold it at a specific RPM it will sort of stutter. I looked for vacuum leaks but couldnt find any, I'll check again. I've also noticed that with the car off but the key in 1 click the VAFC reads -26 vacuum. Is my map sensor bad? Anyone care to comment?

 

bump

 

check your iac sensor, clean it out with brake clean, then see if it still does it.

 

Mine used to do this same thing, I dont know if it matters but I have my throttle body skipped for the coolant line path. I would stage and hold my RPMs at 3000 and about every 3 seconds the RPMs would drop to 2500 or so. It would just repeat that over and over.

 

What did you do to fix the problem?

 

It just went away one day, sorry.

 

damn, I wish mine would do that.

 

I have the same problem ever since I got my JG manifold and throttle body. The check engine light would come on for the IAC and my car idle would jump about 600 or so and sound like a damn heartbeat and would jerk when I pushed the gas. I have to reset the ecu every now and then to make it stop. I have never heard of cleaning it though. Does anyone have any other solutions to this problem?

 

Check your crank angle sensor and plug...

 

How would I check/test this? Any help please, this problem is driving me nuts.