Nextelbuddy

when i use a p72 ecu engine runs perfect. when i use one paticular p28 ecu chipped runs fne too but when i use the one i got off ebay the ecu runs great hard and strong, and idles fine when i first start the car but after i get on it like doggin on it it idle surges between 800 rpms and 1500 rpms. i thought about the IACV but if that was it then the gsr ecu would do the same thing.. any ideas?

STEV3-O

i had same prob but with my p72. im running b16 stock with p72 in my eg. my idle went up and down and i cleaned the iac and it still surged. i then unplugged the hose on the top of the manifold next to the tb that connects to the charcol canister and plugged it up. idle is beautiful now. I aint shure what motor or setup u got but hopefully this will work for u as i know that i hated my idle going up and down. thats my .02 peace [img]surge[/img]

Mike_C

i'm having the same problem, gonna try cleaning the IACV tomorrow.