Help...Rough Idle

[js23881]

Someone help me with this. I have just installed a 402 forged engine with D1 blower. I have 60# moltron injectors. Car runs well except for idle which is ok but generally sucks. It surges someone at idle and also at highway speed when I'm basically just cruising almost at idle rpm (really about 1500 rpm). Is it true my stock throttle body on ls6 intake probably is not giving it enough air at idle and I need to drill a small hole in it to fix?? If so can someone lead me to a thread that discusses this...thanks-

[SSpdDmon]

Originally Posted by js23881

Someone help me with this. I have just installed a 402 forged engine with D1 blower. I have 60# moltron injectors. Car runs well except for idle which is ok but generally sucks. It surges someone at idle and also at highway speed when I'm basically just cruising almost at idle rpm (really about 1500 rpm). Is it true my stock throttle body on ls6 intake probably is not giving it enough air at idle and I need to drill a small hole in it to fix?? If so can someone lead me to a thread that discusses this...thanks-

It might be the injectors. I'd bet money you're runnig rich down low and that is partly leading to idle trouble. You may have to play with or increase the injector timing (ie the injector offsets and min pulse widths) if they aren't opening/closing as fast as the stock injectors were. Typically, 42# injectors and up begin showing idle issues when supporting injector tables are left untouched.

The other possibility is the timing. If it's bouncing all over the place when the surging occurs, that's not going to help matters much.

[95BlueBomber]

I had this problem as well, reduced the minimum injector pulse width down to 1.003 and it took care of it. Hope that helps!