Mechanics

CHEVY NO POWER TO FUEL PUMP

1999 Chevrolet Blazer

Electrical problem
1999 Chevy Blazer 6 cyl Four Wheel Drive Automatic 140000 miles

just installed a new fuel pump because I thought the old one was bad. When I try to start my truck im not hearing the pump come on. Ive checked all the fuses and checked the filter to see if it was clogged. My pump is not working is all I can figure because there is no gas makeing it to the filter. Ive heard that there is a low oil pressure fuel cut off valve on this model of blazer, could this be the problem?
Avatar
Rlmk1109
November 19, 2009.



Welcome to the forum, thanks for the donation. Did you check voltage circuits at the fuel pump relay? Voltage to load side of relay should be hot all the time. Voltage to coil side of relay goes hot for a few seconds, key on, and hot with engine cranking. Voltage to the coil comes from pcm. Can you check for codes?

JDL
Nov 19, 2009.
I have power to one of the 4 fuse entry ports, but after that nothing with the key in the on position.

Tiny
Rlmk1109
Nov 19, 2009.


http://www.2carpros.com/forum/automotive_pictures/170934_blazer_fuel_pump_1.jpg



The green wire with the white tracer is voltage for coil side of relay, hot for a few seconds when you you turn key on, no crank. Engine cranking, should be hot all the time. If nothing there, take circuit loose at both ends, check for continuity, if no continuity, replace wire. If continuity ok, check for pin voltage for that wiring circuit at the pcm. It may not be 12 volts, it maybe 5 or 6? If no voltage when there should be, you need to check the pcm.

JDL
Nov 20, 2009.
What is the PCM and where is it?

Tiny
Rlmk1109
Nov 20, 2009.
On your vehicle, it may be called vcm, vehicle control module. Under the hood, passenger side front. You need to do some testing, before replacing anything.

JDL
Nov 20, 2009.
Do all of your dash lights and radio come on when you turn the key forward?

Tiny
Hilfiger_676
Nov 25, 2009.
Yes, I am getting power to my dash. But to let you know, I did get the thing running. After going back and checking all the fuses and relays, I found that a celnoid on my injection sustem was grinding and makeing a bunch of noise. I took the thing loose from the side of the injection system and cleaned it, put it back on and Bin-Go power went to my fuel pump and the truck fired up. Im going to replace this old celnoid with a new one. Thanks for your help. You got me headed in the right direction and the rest was just back tracking. Thanks again.

Tiny
Rlmk1109
Dec 1, 2009.