vettekid1985

Hello all, i have a 1985 which i have new GM crate long block modified with all the typical performance intake parts ie Performer heads, Arizona Speed runners, BBK throttle body, ported plenum, Big mouth manifold, deleted cold start injector as well as a fairly aggressive Comp camshaft 229/245 .510/.540
custom chip from Harris on ebay

All is well performance wise except for cold starts. It starts well but idle is low (650 +/- low for this size cam) and very choppy until temp gauge reaches 140 then idle picks up and it idles nicely @ 1200rpm or so in park. Until that time i have to constantly work the throttle to keep the rpm's up to reach that target temp, i read online that the coolant temp sensor in the front of the intake is used by the ECM to establish idle rpm, i assume its functioning fine because when i disconnect the harness/plug the cooling fans come on constantly
any thoughts would be welcomed!!

John A. Marker

I would suspect the chip. The cold start injector does nothing more than add a little more fuel at start up. Then your running off the tables in the chip until it is warmed up and you start to run off the sensors feedback to the computer.

blackozvet

I would suspect Harris chip,
the reality is it will cost more to get a better one.