6.0 Stumbles When Cold

[Mudddawg]

HI ALL,

 

I HAVE A 2004 2500HD CREWCAB 6.0 AUTOMATIC 4X4. IT HAS RECENTLY DEVELOPED A PROBLEM OF STUMBLING OR CUTTING OUT UPON INITIAL START UP AND DRIVING AFTER SITTING OVERNIGHT. I CAN CRANK THE TRUCK NO PROBLEMS. BUT WHEN I PUT IN DRIVE AND PRESS THE GAS PEDAL IT STUBLES---BAD! IT WILL CONTINUE TO DUE THIS UNTIL I LET OFF THE GAS THEN PRESS THE GAS AGAIN THEN ALL IS FINE. NO MORE PROBLEMS UNTIL AN OVERNIGHT SITTING. IT ACTS LIKE IT JUST RUNS OUT OF GAS LIKE A STICKING FLOAT IN CARB. NEW PARTS ARE FUEL FILTER (2 OF THEM-AC DELCO) AC DELCO PLUGS AND WIRES, AIR FILTER. IT DOES HAVE FEW MODS, 7" SUPERLIFT, TRUE DUAL FLOWMASTER EXHAUST. I HAVE ALSO CLEANED THE MAF PROPERLY WITH NO RESULTS. ANY IDEAS OR INPUT ARE WELCOMED!!!! NO SERVICE ENGINE LIGHT. NO WARRANTY.

[Nice rig]

It still might throw a code without an engine light.

[Draenor]

How is the fuel pressure?

[Mudddawg]

How is the fuel pressure?

 

I HAVE NOT CHECKED THAT AS THERE IS NO PROBLEM AFTER INTIAL START. THE PROBLEM ONLY LASTS UNTIL I LET OFF THE GAS THEN INSTANTLY PRESS THE GAS. AFTER THAT IT RUNS LIKE A CHAMP. THANKS FOR THE INPUT. I WILL CHECK COLD FUEL PRESSURE. MAYBE A FUEL PRESSURE REGULATOR????

[Mudddawg]

It still might throw a code without an engine light.

 

 

THANK YOU FOR YOUR TIME. I HAVE CHECKED WITH OB2 SCANNER, NO CODES.