I've replaced the fuel pump twice and the wiring harness that connects to the pump this last time. It worked great for about 5 hours, then wouldn't kick on. After sitting a couple days it started for about 10 minutes and quit again. is this a sensor or wiring issue? Please help
Chevrolet Q&AAsk Your Question
2001 Chevrolet Blazer Question: Please help me with my fuel pump issues?
Answer #1G. T. Service Center (4142 Answers) , Stephenville, TX - (254) 638-3236ProfessorG January 05, 2014, 12:35Master
That's a loaded question; First I need to ask, What kind of fuel pump module are you buying and where did you buy them. 2nd how did you and what did you use when you spliced the wires when replacing the connector?
Replymartinlakewylie, January 05, 2014, 13:22Rookie
first one bought at Autozone and don't remember the brand and the one I just put in was a Herko I believe. I used the butt connectors that came with the wiring harness
ReplyProfessorG, January 05, 2014, 14:05Master
What kind of crimp tool and did you solder them.
Replypushrod, January 05, 2014, 14:10Master
IT IS PROBABLY JUST AN IGNITION PROBLEM AND THE PUMP IS OK ANYWAY!!
Answer #2pushrod January 05, 2014, 12:38Master
Security light flashing while cranking?
Replymartinlakewylie, January 05, 2014, 13:27Rookie
Security light is not flashing
Replypushrod, January 05, 2014, 13:30Master
Just wondering, that can cause no pump operation. How about the RELAY? Are you sure the pump is not running for the 3 second prime and when key is cycled to start and that it IS the problem?? Fuel pressure is....???
Replymartinlakewylie, January 05, 2014, 14:19Rookie
The pump is not running and I've tried a new relay. Thanks for all your help.
ReplyProfessorG, January 05, 2014, 14:25Master
The 2000 up GMs will usually have to be cranked momentarily before the pump will reprime for 3 seconds.
Replypushrod, January 05, 2014, 14:26Master
Ok but i have installed a truck load of these GM pump modules without any problem when the pump was at fault to start with!!
So good luck with it! (Wow pg must have hit send same time) I'm done here. Catch ya on the flip side.
Replymartinlakewylie, January 05, 2014, 14:31Rookie
I'm beginning to believe that the pump wasn't the problem
Answer #3cardocIII from Gillespie's Auto Service, January 05, 2014, 15:28Master
The fuel pump grounds to the frame rail just under the drivers left foot. The frame gets its ground through a braided strap that goes from the right front to the engine block. These are known for losing that ground connection. Take a voltmeter connect it to the battery negative and the other lead to the ground eyelet for the fuel pump and try and start the truck. If you measure a voltage more than .3v there is a problem in the ground circuit.
Replypushrod, January 05, 2014, 15:40Master
That would be the black wire with a white tracer if my memory serves me correctly, dont have online repair guide just thoughts! That wire can be grounded at a point that is easily accessed to see IF there is a problem ground! I've done it before!
Replymartinlakewylie, January 17, 2014, 11:50Rookie
if I unhook the battery overnight it works and runs for about 10 minutes. Could this be a sensor or the computer?
ReplycardocIII, January 17, 2014, 14:58Master
All that is would be the kind of information on which to base the testing that needs to be performed. During the ten minutes that it is running, you should be able to get some baseline "known good" testing results, that way the moment that it stops working you can test for what is now missing efficiently. An example would be the fuel pump relay is commanded on by the PCM. If you lose fuel pressure and the pump isn't getting any power then you need to know if you lost the command from the PCM to the relay, or if you just lost the output from it. If the relay is operational and there is power there, but not at the pump, then you have to find where the circuit failed in-between those two points. That's the only way any of this gets done efficiently.