Intermittent Fuel Pump
#1
06-22-2010, 08:22 PM
Intermittent Fuel Pump
2001 2 Door
Drove it to work and then it wouldn't start - fuel pump didn't run; had it towed to shop. They cleaned the harness / relay connectors at under hood box. It started running. 2 days later, same thing, no fuel pump. This time they replaced fuel pump, although I'm sure it isn't the issue. It works for a couple of days then same thing (its not going back to same shop!). Fuel pump relay is engaging for about 1 second but pump never turns on. No service engine light. Owned truck for 14 months and fuel gauge has always "wandered" when ideling but not when in gear (automatic).
Any help is really appreciated!!
Drove it to work and then it wouldn't start - fuel pump didn't run; had it towed to shop. They cleaned the harness / relay connectors at under hood box. It started running. 2 days later, same thing, no fuel pump. This time they replaced fuel pump, although I'm sure it isn't the issue. It works for a couple of days then same thing (its not going back to same shop!). Fuel pump relay is engaging for about 1 second but pump never turns on. No service engine light. Owned truck for 14 months and fuel gauge has always "wandered" when ideling but not when in gear (automatic).
Any help is really appreciated!!
#2
06-22-2010, 10:58 PM
Fuel pump relay is like $8, replace it for peace of mind if nothing else.
Fuel pump and fuel pressure gauge are one unit, your gas gauge needle should not be wandering with the new pump unit.
Check your oil pressure sending unit, it is tied into the fuel pump circuit. Part of a safety feature, not enough oil pressure and it kills the fuel pump.
Replace your fuel filter, verify it is installed in the right flow direction.
When the truck doesnt start, does the Security light come on? If so, check your ignition switch.
There wont be a CEL for a fuel problem, at least fuel pressure problem. GM doesnt monitor fuel pressure, it does monitor vacuum pressure within the fuel system. Its a closed system.
Hope that helps, post up any other observations or current problems.
Fuel pump and fuel pressure gauge are one unit, your gas gauge needle should not be wandering with the new pump unit.
Check your oil pressure sending unit, it is tied into the fuel pump circuit. Part of a safety feature, not enough oil pressure and it kills the fuel pump.
Replace your fuel filter, verify it is installed in the right flow direction.
When the truck doesnt start, does the Security light come on? If so, check your ignition switch.
There wont be a CEL for a fuel problem, at least fuel pressure problem. GM doesnt monitor fuel pressure, it does monitor vacuum pressure within the fuel system. Its a closed system.
Hope that helps, post up any other observations or current problems.
#3
07-09-2010, 08:58 PM
...I have a 1998 blazer, 110000miles. Replaced fuel pump assembly in 2009. It started out when I went out to start truck and it would rotate but not turn over. I checked the battery and I could feel the pump relay fuse clicking when I turn the key on. but I don't hear the pump priming. Then the next day I drove around town and it was okay again. But after a few days, the truck starts stalling again. I got home and I pulled the pump relay fuse, put it back in, but truck won't start. That same day I replaced the relay but still not working. Some people have told me the wiring harness for the pump could have melted wires in it causing problem. Could this be the problem?
Last edited by michaelross; 07-12-2010 at 10:42 PM.
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