1987 Chevy 5.7L TBI Fuel Issues

[bbush44]

Hello,
I have a 1987 Chevy, half-ton, 4x4, with 5.7L TBI engine. I have owned the truck since 2000, and it has been my work, hunt, fun vehicle. About 5 years ago, the steering gear had such a bad leak I parked it until I had time to replace it. Well life has slowed down a bit, and I am getting it back on the road. I replaced the steering gear so that problem is solved.
Next problem, while it sat the passenger side tank rusted through and leaks. I never put a lot of miles on the truck so don't really need dual tanks. I removed the passenger side tank and plugged the lines at the cross over switch. When I put a battery in the truck, and turned the key I do not hear the fuel pump build up pressure in the driver side tank. I checked connections and fuses and all was good. I ran 12v directly to the pump, and still nothing.
I dropped the driver side tank, and it appears the fuel pump rotted away the years it sat. I found an aftermarket fuel pump and replaced it. I also replaced the fuel filter while I was at it.
I put the battery back in, and turn the key still nothing from the fuel pump. I check connections and fuses again, and all is good. When I turn it over there is no fuel at the throttle body. If I spray fuel in the throttle body the engine will run until the fuel is gone.
Did I get a bad aftermarket fuel pump?
Is there something I can check to confirm this or not?
Any other suggestions? I am stumped.
Thank you in advance.
Brian

 

[foamypirate]

First thing I'd try is running 12v to the red test lead on the firewall next to the FP relay. If the pump runs, then you potentially have a bad relay, or issues with the wiring to the pump. Also, a silly question, what position is the Fuel Tank selector switch at in the cab? Make sure it's on the correct tank.

 

[bbush44]

First thing I'd try is running 12v to the red test lead on the firewall next to the FP relay. If the pump runs, then you potentially have a bad relay, or issues with the wiring to the pump.

Thanks foamypirate, I will need to try running 12v to the test lead on the firewall. Just 12V right from the battery, does the key need to be on, etc?

Also, a silly question, what position is the Fuel Tank selector switch at in the cab? Make sure it's on the correct tank.

Not a silly question, but yes it is on the correct tank.
Thanks
Brian

 

[foamypirate]

Thanks foamypirate, I will need to try running 12v to the test lead on the firewall. Just 12V right from the battery, does the key need to be on, etc?


Not a silly question, but yes it is on the correct tank.
Thanks
Brian

12V straight from the battery will do the trick, no need for the ignition to be on. That lead is a straight connection to the 12v+ side of the fuel pump.

 

[bbush44]

12V straight from the battery will do the trick, no need for the ignition to be on. That lead is a straight connection to the 12v+ side of the fuel pump.

Thanks Foamypirate, I will give that a try this weekend when I am back home.

 

[bbush44]

I didn't get as much time this weekend as I planned to look into this issue, but I did run 12V to the test lead, and they pump did not run.
So where do I go from here?
Check the connections at the pump?
Any other connections to check?
Has anyone ever had a aftermarket fuel pump show up bad?
This is the pump I purchased.
http://www.ebay.com/itm/191000689964?_trksid=p2059210.m2749.l2649&ssPageName=STRK:MEBIDX:IT
Thanks in advance.
Brian

 

[foamypirate]

I didn't get as much time this weekend as I planned to look into this issue, but I did run 12V to the test lead, and they pump did not run.
So where do I go from here?
Check the connections at the pump?
Any other connections to check?
Has anyone ever had a aftermarket fuel pump show up bad?
This is the pump I purchased.
http://www.ebay.com/itm/191000689964?_trksid=p2059210.m2749.l2649&ssPageName=STRK:MEBIDX:IT
Thanks in advance.
Brian

The aftermarket pumps have a pretty spotty reputation. First thing to check though would be the wiring. There are grounds from the sending unit to the frame. I can't remembe if they tie into the pump or just the fuel gauge circuit, but probably not a bad idea to check and make sure they are solid. From there, I would check the 12v+ wiring. You should be able to disconnect the plug going to each pump and check the brown or gray wire (depending on the side) for 12v+ when you have the battery hooked to the test lead on the firewall. If you still don't have 12v+, you have a wiring issue. If you DO have 12v+, you either have a bad pump or a bad jumper harness.

If it ends up being a bad pump, I'd go with a new ACDelco from RockAuto. I've been running two of them (one in each tank) for about 2 years now without issue. They really aren't terribly expensive for the peace of mind.