98 ecm on heads/cam car idles high - sometimes
10-19-2011, 01:18 PM
#1
98 ecm on heads/cam car idles high - sometimes Ok, I figured id throw this thread on here and see if anyone has any ideas about it. Im running a 98 ecm in my 98 z28. Its a new ecm. Basically a stock short block with ported heads and 236/242 cam. Now, I purchased the car a few years ago, and with the tune it had on it from TSP, cam only, it would idle high when I reached stop lights. This is only intermittently. I wrecked the car last year, and after building it back to it's former glory, installed ported 5.3 heads on it. I had it tuned by a different shop, and even installed a brand new 98 ecm. Now, it acts the same way. Im thinking it's just the fact that it's a 98 ecm, as I've heard they are inferior to the 2002's. I've checked for vacuum leaks, I know the throttle body is adjusted correctly, and the IAC is new. The spark plugs are a bronze color, and as far as I know, the tune is up to par from looking at the dyno numbers. Any opinions would be greatly appreciated. Thanks!
Last edited by 98Zheadsncam; 10-19-2011 at 01:56 PM.
10-20-2011, 07:39 AM
#4
Ok, thanks for the input. When I'm able to get my buddy with EFI live over, I'll have him make a copy. I'm assuming the timing is pulled back a bit though, the highest we have around here is 91 octane. When I start the car for the first time in the morning, I can hear the IAC sucking in air, and the rpm's lope up and down a bit, but eventually even off.
