fuel pump troubleshooting

[LRflip]

1) Sorry, don't know

2) It's the black box on the passenger fender. It's about the size of a pack of cigarettes.

3) Don't think so but not sure.

4) Fuel pressure?

The black box is the Multi function unit...that thing is for all sorts of stuff.

The fuel pump relay is on the passengerside kick panel...I think its like an aqua color.

The fuel pump is the same as a Chevy 350 Fuel pump at autozone...

 

[LRflip]

And the harness is an easy fix...You can check the power to that from where it runs off of the main vehicle harness....

Its just a PITA to get to.

 

[ethanrover98]

okay..........hopefully my last question regarding my fuel pump dilema......

Will the Airtex E3270 pump work in lieu of the Master E3270 pump when performing the pump rebuild that boulderbear so graciously outlined in a previous post....

thanks in advance for the help.........

 

[ptschram]

Flip and Joey-review your wiring diagrams, the only fuel pump relays on GEMS trucks are in the multi-function relay, referred to as Z207 in the ETM.

I no longer even suggest the CB fuel pump repair after having personally experienced a failure when the hose barb broke from the fuel pump. The hose was close enough that you'd get some fuel pressure, but as soon as you accelerated, it would fall on its face and fuel pressure fell to zero as soon as the key was turned off.

When diagnosing fuel pump issues, it is a really good idea to keep an eye on the current. When the pumps finally go bad, the current can increase to the point that the measured voltage falls to zero. I chased one of these for a year before realizing why it was failing on a regular basis.

We have aftermarket fuel pump assemblies almost as cheap as the pump alone.

 

[peter sherman]

Flip and Joey-review your wiring diagrams, the only fuel pump relays on GEMS trucks are in the multi-function relay, referred to as Z207 in the ETM.

I no longer even suggest the CB fuel pump repair after having personally experienced a failure when the hose barb broke from the fuel pump. The hose was close enough that you'd get some fuel pressure, but as soon as you accelerated, it would fall on its face and fuel pressure fell to zero as soon as the key was turned off.

When diagnosing fuel pump issues, it is a really good idea to keep an eye on the current. When the pumps finally go bad, the current can increase to the point that the measured voltage falls to zero. I chased one of these for a year before realizing why it was failing on a regular basis.

We have aftermarket fuel pump assemblies almost as cheap as the pump alone.

Don't be shy Paul post the price!
I had mine slide off the barb ran ok. 2 hose clamps seems to have solved the issue for now.

 

[ptschram]

Don't be shy Paul post the price!
I had mine slide off the barb ran ok. 2 hose clamps seems to have solved the issue for now.

I'm embarrassed to say that things have gotten to the point where I'm not aware of the price. LOL

I just sell the jobs and do the hard work, Gary sells the parts.

 

[peter sherman]

I'm embarrassed to say that things have gotten to the point where I'm not aware of the price. LOL

I just sell the jobs and do the hard work, Gary sells the parts.

Hey are you wheeling with us next weekend in the north woods!

 

[ptschram]

Hey are you wheeling with us next weekend in the north woods!

No, we have a social engagement with a bunch of friends of ours, going to see some guitarist that plays with the Dave Matthews Band.

My Disco is in the garage attached to the house with no front body panels on it in anticipation of either repairing the holes in the floor of finding another body to put the mods onto.

Have faith, even SWMBO has been Jonesing for a trip to the UP. I got the 4.2 shortblock done, I'm getting closer.

 

[ethanrover98]

My saga continues.........I replaced the pump (which was bad, only producing 18psi at the rail), but my initial problem still exsists......the pump will only run while hot wired. Here is the frustrating part.....I have 12v at the connector pins for the pump and 5 volts on the two pins for the fuel gage. When I turn the key to the 2nd positon I have 12v for about 20 seconds and then it goes to zero (just like it should). When I hook the connector to the pump....NOTHING!!!!

I cut the cover off of the multifunction unit and noticed that when the truck is running only 2 of 3 relays are energized (the two together are energized, the one by itself is not). If I hold the contacts on the one that is not energized nothing happens.

I jumped the emergency cutoff switch and again...nothing.......

All fuses are good (replaced all of them anyways)

All grounds and the harness connection in the wheel well are good......I think?!

I'm stumped..............any thoughts would be greatly appreciated......