Question"I have had a 98 Chevy 3500 HD truck since new, its a 16000lb gross weight, with 39000 miles, yes 39000. It starts cold very well, when its hot it cranks along
time, maybe 10-20 seconds. It's a 454 auto 2wd [dually). I've had it to several dealerships and a GM truck center, they have replaced the fuel pump 4 times, the
regulator (inside frame rail in front of tank) fuel pressure has always been 60 or above. Not a single technician in over 35 techs I've talked to - no body can figure this out. Also, there is 2 fuel tanks, the front (main) has the fuel pump inside of it, the back has a transfer pump in it. When the fuel gauge in the dash reads half tank, it won't start. Fuel pressure at that time I don't know, haven't been able to get it to a dealership then. Even though I've pulled the fuel pump myself, the main tank has had gas in it. Put a few gallons in it and then it starts. At about 20000
miles a new head gasket on passenger side only was done by the truck center. Please help me out.
AnswerHi Bob,
Your average light truck, the fuel pump should run for two seconds after the key is turned to run.
Yours should have a hot fuel handling module, which causes the pump to operate for about 8 to 11 seconds, in order to circulate more fuel through the fuel rails, and push out any vapors with cool fuel. See if your pump runs that long.
As for the half tank problem, I can't immagine that you or someone hasn't checked the ground connection at the frame near the pump, but the sending unit and the pump use the same ground. If it isn't good at the frame, I can see where the pump ground might feed back through the gas guage, and under half a tank, the resistance in that circuit may be not enough to run the pump. Can you hear the pump run at that time?
Then, there could be a problem with the hot fuel handling module. Were they aware it has one?
That is grasping at straws, and I haven't seen the problem, but just an idea that comes to my mind.
