The motor idles fine when parked but, once the car moves the idle sits at around 2k rpm until the vehicle comes to a complete stop then it drops back down to 1k rpm. It does not matter what speed, 5mph or 65mph put it neutral rpm will sit at around 2k until complete stop. I can drive it to 30mph leave it in 3rd gear take my foot off the pedal and cruise rpm will sit around 2k. I have checked all vacuum lines and IAC which is the only thing that I can think of that cause idle issues. The motor was tuned on crome and runs really good other than this. Also since this idle problem happen the car went from 290 miles on a full tank of gas to about 240 miles.

Setup is: B18a/GSR
68mm tb
blox IM
pro 1 cams
p30 pistons
stock fuel system

Any input or opinions is appreciated. Thanks.

 

Checked valve lash, compression, and timing all seems good. When I get a better header I'll get it re-tuned and hopefully it will solve this problem.

Is this the characteristic of the pro 1 cams or upgraded cams?

 

i'm having this same issue too. bump for an answer.