Need TBI help

[chevyjeff]

My 350 tbi has a problem that has me stumped. First I am getting no ses light (no codes). What it is doing is when I go to start it (cold) like after it has sat overnight or all day at work the truck wont start unless I put the gas pedal to the floor (acts like it flooded). It will briefly fire then nothing. Hold the pedal to the floor and it will start but run rough and put out lots of black smoke. Its acting like whatever controls the increase in air flow during open loop is not functioning. After it has warmed up (closed loop) it runs great and will start every time. I guess what I need to know is what controls the increase in airflow during open loop operation and what to look for as a solution? Its getting plenty of fuel on cold start but not enough air.

 

[HarryH3]

Hook up a scanner and see what the ECM thinks that the engine temp is. It sounds like the coolant sensor circuit is whacked, causing the ECM to think the engine is VERY cold. That will cause it to dump in a lot of extra fuel during cranking. /forums/images/graemlins/eek.gif