98 Chevy 4.3 Engine No Fuel Pressure

marvinteck · March 20, 2011

I just recently bought a 98 Chevy 1500 and it wont start due to only having 7psi of fuel pressure. I replaced the fuel pump and fuel pressure regulator with no improvement. The fuel filter is good. The injectors arent leaking. Its almost like the fuel injection spider has a internal leak. any suggestions?

tbhuge · March 20, 2011

How many miles on the truck?

GMstrong · March 20, 2011

Could be a bad wiring to the fuel pump.or a weak sending unit.miles doesn't have anything to do with this problem

marvinteck · March 20, 2011

I ran my own little test and i am not getting any fuel pressure from the tank. I just replaced the fuel pump and sender assembly not even 24 hours ago. Im purplexed why the new pump would be doing the same thing as the old one. I will keep yall updated.

Update on sunday night: I think I narrowed down my fuel pressure problem. The old fuel pump was a cheap generic airtex one. The rubber piece that the fuel pump outlet sticks into on the sender unit rotted away. The pump was running but was just recirculating the fuel within the tank. This would explain the gradual decline from hard starts into a no start condition with no fuel pressure but some flow.

Why wasnt the new one working. I dropped the tank again and the pump was pumping perfectly. I got into a rush last night when I put the fuel tank back in last night. The rear tank strap wasnt all the way tightened up making the tank sag in the rear. I added two or three gallons of fuel last night to the tank. I had hardly no fuel pressure. I think the most of fuel was sitting in the rear of the tank and the sender was sucking air along with fuel producing the same result as the old pump (no pressure but some flow).

I am planning on reinstalling the tank monday after work and filling up the tank to see what fuel pressure I get up at the fuel rail now. I feel fuelish for making such a dumb mistake. I would much rather be red in the face than have to pay another $250 to $400 for a new spider. I am crossing my fingers hoping I found the soulution to my problem

marvinteck · March 22, 2011

Monday night. Still fighting this thing. I got it all back together today after work. I need to get the battery charged up tuesday at work because it wont crank the engine right now. Currently I have 65PSI Key On Engine Off. As soon as the pump shuts off the pressure bleeds back down . Will continue to fiddle with it tommorrow. Hoping I can get it at least running tommorrow and then I can chase down why its not maintaining pressure.

marvinteck · April 2, 2011

Monday night. Still fighting this thing. I got it all back together today after work. I need to get the battery charged up tuesday at work because it wont crank the engine right now. Currently I have 65PSI Key On Engine Off. As soon as the pump shuts off the pressure bleeds back down . Will continue to fiddle with it tommorrow. Hoping I can get it at least running tommorrow and then I can chase down why its not maintaining pressure.

Its right as rain now. Been driving it 3-4 days now and it hasnt missed a beat yet. Runs a whole lot better than my previous daily driver which was a 1986 f150 with over 200k on it.