Help!

I have a 99 Chevy Tahoe 4 door 4wheel drive with a 5.7 engine. I had replaced my fuel pump with a Airtex pump. After one year of use my fuel pump stopped coming on. So I replaced it with a AC/Delco fuel pump. Now that pump does not come on. I have checked the fuel pump relay, it clicks on. Can anyone point me in the right direction as to what else to check. Right now I am thinking the ECM may be bad. Thanks!

Did you check for voltage at the fuel pump connector, engine cranking, the gray wire is voltage. Black wire is ground. Use a voltage tester.

At the fuel pump relay, there are two voltage sources. One for the load side of relay and one for control side of relay. The voltage for the load/switch side of relay is fuse protected.

I have a 99 Chevy Tahoe 4 door 4wheel drive with a 5.7 engine. I had replaced my fuel pump with a Airtex pump. After one year of use my fuel pump stopped coming on. So I replaced it with a AC/Delco fuel pump. Now that pump does not come on. I have checked the fuel pump relay, it clicks on. Can anyone point me in the right direction as to what else to check. Right now I am thinking the ECM may be bad. Thanks!


when you installed the new ac/delco pump did you cut any wires ? or did it just plug in to the on board connector ?

did you check all fuses with a voltmeter ? check the ground at the frame rail next to the fuel pump.

relay clicking is only the coil control. the contacts are another circuit and this as mentioned needs a voltage check to see if its the relay contacts worn..

WHEN THEY GET THIS OLD REPLACE RELAY AND FUEL FILTER WHEN THE FUEL PUMP IS DEFECTIVE.

prior to replacing did you check out why the Airtex pump was not operating ?

you got 1 year out of the airtex is a very good amount.

Check the "ECM B" fuse, 20a, fuse #11 in the underhood fuse block. This is the power to the pump when the relay is energized. Since you can hear or feel the relay kicking in I would not suspect the VCM at this time.

Replacing an inop fuel pump is about #20 on the diagnostic chart.

Check out this site for affordable and comprehensive service manuals.

http://www.alldatadiy.com/?gclid=CPzVvL-crawCFYwaQgodbTIPIA

Yes I checked the voltage. None at fuel pump when cranking.

When I installed the Airtex pump a year ago, I had to cut the pigtail to hook up the Airtex pump. Had to remove that pigtail and put the one that came with the AC/Delco pump. All connections are clean and tight. I had bypassed the pump relay and still nothing.

Check the "ECM B" fuse, 20a, fuse #11 in the underhood fuse block. This is the power to the pump when the relay is energized. Since you can hear or feel the relay kicking in I would not suspect the VCM at this time.

Replacing an inop fuel pump is about #20 on the diagnostic chart.

Check out this site for affordable and comprehensive service manuals.

http://www.alldatadiy.com/?gclid=CPzVvL-crawCFYwaQgodbTIPIA

That was the first thing I checked was the fuse. It was good.

That was the first thing I checked was the fuse. It was good.

check that you have voltage at the fuse, then relay contacts, jump relay contacts and look for voltage at the pump connector at the fuel tank.

don't forget that a proper ground/return is just as important as a feed voltage.

When I installed the Airtex pump a year ago, I had to cut the pigtail to hook up the Airtex pump. Had to remove that pigtail and put the one that came with the AC/Delco pump. All connections are clean and tight. I had bypassed the pump relay and still nothing.


how did you make these connections ? what method did you use ?