after my truck sits long enough for the engine to get cold - it starts up fine.. but if i try to go it bucks and sputters something awful... HOWEVER if i start it and let it idle for 10/15 minutes and get warmed up it runs like a dream and continues to run nicely when its warm. I've tested the IAC, MAP, and coolant temp sensors which all seemed O.K., the truck was storing a code for an oxygen sensor which we also replaced. we have also tried plugs AND wires, replaced the throttle position sensor, and a new tank of high octane gas. any ideas what else to try? im stumped.. 1992 s-10 Blazer 4.3 vortec CPI

 

It is possible that the connector on the injector inside the intake is a bit loose and the heat tightens things up a bit...

 

My more recent 2000 4x4 4dr LT does the same thing IF once I start it up like right after I go then it gives me a hard time. But I just let it sit there for a min or two let the car's juices go flowing so to say. I just never though it was a problem I just let it heat up for a few minutes like I just said. I replaced plugs and wires also but I don't run premium.

 

I am a firm believer in letting a truck warm up before running it anyway.

 

Just a thought but maybe you have fuel leaking in your plenum when it is cold. After it warms the leak may be stopping. The fuel lines and and the injector are notorious for leaking and it will make it run as you described.

 

kind of late reply, but turns out the 6 point injector was leaking when cold costing about $500 parts and labor, thanks for the help all

 

thanks for the follow up, its never to late to let us know how it went. It could help someone else later on.