Idle Problem

[s13400hp]

I bought a motorset and it had a tuned ecu. But for some reason not turning on. So switched to stock ecu. But engine has 550cc injectors with no tuning. it backfires. So i was wondering would that cause it to idle rough.

[Z U L8R]

a lot of things can cause it to idle that way. you need to do more investigation on your own to at least narrow it down a little. ur post is too vague to say BOOM! I KNOW EXACTLY WHAT IT IS! DO THIS__________

Dave

[punxva]

switching the ecu back to stock then it will idle like ass, since you have larger injectors. I'd try to get a tuner to look at that ecu, or figure out what company tuned it and send it back to them