LSX Fuel Pump not Priming

[89Sport16]

05 5.3 in an 89 C1500, returnless fuel rail with corvette regulator. I did the swap two years ago and used the newer 98 AC Delco pump in the tank. About a month ago, the engine started stumbling on startup, then one day it wouldn’t start and the fuel pump quit priming. I’ve checked the grounds, swapped out relays and fuses, no luck. I’m surprised the pump would die after only two years, but it sure is pointing to replacing the fuel pump.

So before I jack the truck in the air and drop the tank, does anyone have any other suggestions? I plan on checking the voltage before I get another pump, I think I used the stock wiring, so I might be able to check the voltage at the plug near the firewall before I drop the tank.

What about a replacement pump, should I go with a Walbro or something other than the AC Delco?

Thanks!

 

[Busted Knuckle]

05 5.3 in an 89 C1500, returnless fuel rail with corvette regulator. I did the swap two years ago and used the newer 98 AC Delco pump in the tank. About a month ago, the engine started stumbling on startup, then one day it wouldn’t start and the fuel pump quit priming. I’ve checked the grounds, swapped out relays and fuses, no luck. I’m surprised the pump would die after only two years, but it sure is pointing to replacing the fuel pump.

So before I jack the truck in the air and drop the tank, does anyone have any other suggestions? I plan on checking the voltage before I get another pump, I think I used the stock wiring, so I might be able to check the voltage at the plug near the firewall before I drop the tank.

What about a replacement pump, should I go with a Walbro or something other than the AC Delco?

Thanks!

The GM in-tank pumps can't be deadheaded or they burn out. It has to be a recirculating design. Otherwise you need to tap the tank and use an external old school pump that is specified to be deadheaded.

 

[Dropped88]

With corvette filter its not deadheaded it does recirc back to tank

Also I dont know you wired it but you could check at relay. But if you can check power and ground at sending at tank would be best

 

[thegawd]

I had a delphi pump die in my burb after 13 months.... I was pissed.

Al

 

[89Sport16]

The GM in-tank pumps can't be deadheaded or they burn out. It has to be a recirculating design. Otherwise you need to tap the tank and use an external old school pump that is specified to be deadheaded.

The corvette regulator has a return line back to the tank.

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[Busted Knuckle]

With corvette filter its not deadheaded it does recirc back to tank

Also I dont know you wired it but you could check at relay. But if you can check power and ground at sending at tank would be best

Good point about the power and ground. Ground especially. I ground a clean spot onto the chassis and used a stainless nut, bolt, washers for the suburban spiff. Some racers will use a +12V thicker wire. For stock pump the existing wire is OK.

 

[89Sport16]

Well, ended up being pretty simple, after metering and not getting a 12V signal at the firewall, I was a bit relived when I put 12V to the fuel pump wire, I was not looking forward to dropping the tank. I worked my way back and found the ground terminal inside the relay connector was pushed out..

Once fixed the terminal, fired right up.