98 Tahoe with a 5.7 “sputters” when accelerating only when engine is cold. “Sputter” symptoms feel like engine or transmission is skipping or jumping erratically. This only occurs when engine is cold and when accelerating. Engine idle feels okay and it starts fine. Runs great after about 10 miles of driving and engine gets warm. Originally, sputter was only felt only during acceleration from 1<SUP>st</SUP> to 2<SUP>nd</SUP> but now “sputter” is getting worse and is felt up through 2<SUP>nd </SUP>gear. Problem seems to be worse after truck sits a couple of days. I already installed new fuel pump and intake gasket fairly recently (not related to this problem). Intake gasket problem did cause antifreeze to leak through exhaust system, so I’m thinking the cats might be internally rusted causing back pressure and backfiring through throttle body which could be a “sputter” symptom. My only other thought based on reading other forums is the spider injectors. Question: could blocked cats or internal fuel leak be the culprit for cold/acceleration problem if all is well after everything is warmed up? Any help would be greatly appreciated.

 

Welcome to the forum.

Check fuel pressure. Did you replace fuel filter w/ new pump? Also several have said that now OEM fuel pumps don't last long.

 

first replacement fuel pump and filter around 80k. Recent new fuel pump and filter at 105k. Second one came with new pigtail with larger conductors. Soldered everything together. Seems to be fine...no winding noise and runs fine.

 

I know someone that had a problem that sounds like yours. After replacing all kinds of stuff, he was told it could be the distributor pickup coil. Replaced the distributor and the problem was solved. Not sure if it was the pickup coil but that was about the only part on the distributor that was not new.

 

Hmmmmm. New cap and rotor about 5k miles ago. Pick up coil seems unlikely since all is fine after truck warms up. Will remove and inspect cap and clean though. I did replace ECT sensor from another lead and I still have the cold stutter. Any other thoughts???

 

Thanks for the distributor advise. I pulled one from the bone yard for $30 and reused my old cap and rotor. The pick up coil and main distributor were replaced. The old distributor gear was significantly worn. I haven't had the problem in the last two days so I think the problem was resolved. THANKS AGAIN.

 

Glad that you got it taken care of. hope that takes care of the problem.