Eddie1966

Ok you chevy guy's here is one for you. I have a 04 calvalier that the fuel pump stop working in. Checked the relay and it was fine. Unplugged the fuel pump harness from the body and used a voltmeter and had power on the plug. So put in a new pump. Now here's the kicker the new pump failed to work. Pulled the tank back out and use test leads and tested the pump and it work fine. rechecked for power at the plug on the body it checked ok. did a continuity check on each wire on the little harness that ran from the body plug to the fuel pump and they all checked out fine. I'm at a loss.

The only other thing that i can think of is i had to take the old sensor (I think it is called a fuel pressure sensor) off the old fuel pump and put on the new one. I don't have a wiring diagram on this car so i don't know if this sensor
has any thing to do with this or not. But guess it possible this was the problem all along.
Any thoughts or suggestions ?
Thanks for any help,
EddieP

Makemyenginerun

Did you find your answer to this? I have the same issue.

Makemyenginerun

I changed the flex fuel pump. It has factory connnectors. I put a voltage meter on the pump connector and I get 12 volts. With the connector on the pump and the gas tank disconnected from the fuel lines the pump will spit fuel only when a jumper wire is placed across the gate of the relay. The relay was changed out with 4 other identical relays in the fuse panel, however none let the pump spit fuel while cranking over the starter. I don't think the ECM is sending a ground signal. I don't get it because the other pump I took out was working. Just not so great under 1/4 tank.

Makemyenginerun

I have to check for a flashing security signal on the dash and codes.

tech2

what year and engine

Makemyenginerun

I have a 2002 vin Z Tahoe 5.3 L

Makemyenginerun

I don't understand why there isn't a fuse for the fuel pump when there is a fuse for even the smallest windshield washer motors unless that circuit is coupled with another circuit and labeled differently. This vehicle has an ignition switch or I should say a new ignition tumbler. I'm not sure if there is something in the steering column I need to check. Nothing can be easy it seems.

tech2

welcome to the forum. fyi this is the cavalier section. in the future post in the Tahoe section.

the fuse for the fp relay is the ecm b fuse 20 amp. if there is not removable fuel pump relay....the relay may be part of a printed circuit board...ie part of the underhood bus electrical center ie fuse box.

oilcanhenry

I have read about many parts, that are now made in China or some other 3rd world country, not working properly or at all. Quality control seems to be almost non-existent. Never should have allowed NAFTA and GATT to be signed into law. lots of American jobs lost and garbage parts and devices sent to the US and other countries.

Heck the working conditions are so bad that employees have been committing suicide by jumping off the buildings there, per Apple/iPhone plants in particular. Working 12 hours, seven days a week 365 days a year is commonplace in countries like China. Why would these poor people care at all about what they were manufacturing?

Eddie1966

Update:
Well after some health issues and some major cursing I finally got the cavalier running again. If I test my voltage at the plug I would have 12.7 volts. but as soon as I plug the pump up
my voltage would drop off to nothing. Some where from the relay to the pump My amperage would fall with the load and drop my voltage to 0. I had never seen this in any vehicle and it
drove me to the point where I wanted to nock the windows out of it. But in stead I continued to try to fine the fault in the hot wire with no luck. I finally ran a new wire from the relay to the
pump and it has been running fine ever since.