Dead fuel pump.?

**JRSully** · #1 11-29-2009, 01:13 AM

Went out out fire up the Ol L78 and it was no go,specifically, NO FUEL to the carb (ran fine 2 weeks ago and at leasts 10 gallons of fuel in tank). 1st thought, dead fuel pump,(but they really don't go bad like that.?). Had another used pump laying around, bolted that on, still nuthin. Blew out the line to the tank and the carb, ok there. Only possible scenarios I can think of:

1. Both pumps are bad (remote at best)
2. Problem with the fuel pump shaft.?

Anbody have this issue with an L78.? Thx in advance

**markjohnson** · #2 11-29-2009, 01:27 AM

Yeah, there's a possiblity that you installed the new fuel pump with the spring-loaded arm on top of the pushrod instead of the end of it. It's actually pretty easy to do by mistake. Be careful with a bad fuel pump, if that diaphragm is ripped, it can fill & dilute the engine oil with gasoline.

**JRSully** · #3 11-29-2009, 01:41 AM

I thought I had that pushrod up there high enough to get the FP arm under (used the old grease trick) going to play with it again tomorrow morning.Thx

**MosportGreen66** · #4 11-29-2009, 02:09 AM

Jim, do you check your fuses?

**JRSully** · #5 11-29-2009, 02:45 AM

I should check the fuses, but that would not stop the mechanical flow of fuel through the line/pump/carb. The pump and carb are bone dry after repeated cranking

**Mr70** · #6 11-29-2009, 03:00 AM

My L-78 has to be cranked for along time after sitting for a long time,to get gas back up in the system again.
5 minutes or more sometimes..
Have you adjusted/messed with your Holleys float to needle valve lately?

**JRSully** · #7 11-29-2009, 03:07 AM

Car has run flawlessly for a while, didn't mess with anything,no need to. Last ran it 2 weeks ago, no problems at all, puzzling to say the least

Verne_Frantz · #8 11-29-2009, 03:19 AM

Sully,
I assume it ran fine when you shut it down the last time. You've tried 2 fuel pumps and blown out the lines to the tank. Try isolating the delivery problem to the carb by removing the fuel line from the carb and crank it with a catch can to see if fuel "wants" to enter the carb. At least you'll know if it's something in the carb or in the path from the tank to the carb.
Verne

Verne_Frantz · #9 12-02-2009, 07:11 AM

Sully, what the heck is going on with your fuel delivery problems?

njsteve · #10 12-02-2009, 07:17 AM

Check the short sections of rubber fuel hose that connect the steel lines by the subframe, by the tank and from the steel lines to the pump inlet. I have seen some old rubber hoses delaminate/seperate internally and then collapse when suction is applied from the pump. They may look fine from the outside but could be completely blocked inside.

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