Have a good friend with a 03 2500 48re 2wd.133k towing about 8k 90% of the time.ON COLD START it starts and dies two or three times.Once in a while on hot restart it does not idle smooth(hunts)and drives 50 or 100 feet and stalls.On restart will have smooth idle and also run ok.No smoke on cold or hot start.Fuel filter new(2 in a week just in case)Just started doing this about 10 days ago.No check engine light.Advise please.

 

Something in the fuel system, either the control valve on the main pump (only electrical connector on the main pump) or lift pump. Probably lift pump. You can check pressure or do the actual lift pump test (must have at least 500ml in 10 sec.)

 

Thanks for info.He'll do his own volume check.He DID change fuel filter AGAIN this afternoon and said new one was somwewhat black and felt gritty/rough and NOW its not doing it! I said pump could be getting weak and not drawing fuel through a somewhat dirty filter.He needs to test it.

 

A fuel pressure guage will tell him alot.