Greetings! (non F-Body related....)

I have an '89 truck with the Holley 670 TBI, that runs really rich when cold. By rich I mean, rough idle, blue/black smoke. After it warms up, it runs excellent! I've tried some adjustments suggested by Holley Tech, to no avail (adjust TPS, reduce fuel pressure). Truck is stock otherwise, except free flow exhaust (no cat) and open element air cleaner. New, or recently replaced - O2 sensor, cts, fuel filter, fuel pump. No codes displayed.

'89 Suburban 4x4 5.7, Turbo 400, 225k miles.

Thanks, all suggestions appreciated.

 

Are you running the Holley injectors if so swap them out with the stock injector pod and see if that helps any. Just a thought.

Steve