Fuel pump losing prime

[J Lee]

my 79 blazer has had this problem ever since I bought it. It had been sitting for a while when I bought it but you could fill the carb bowls with gas a couple times and it would prime up and run but would lose prime if allowed to sit overnight. I assumed this was due to the junk Edelbrock carb that was on it and the fuel pump going bad. I have now changed the carb to a new 600cfm Holley and replaced the fuel pump but the problem is still there. once it is primed in the manner described above it is fine and will run and will crank again after sitting a short period but the pump is still loseing prime if it sits overnight. All the lines are tight and it is not leaking gas anywhere so I can't figure out what could be causing it now. any help would be greatly appreciated.

Jeff Lee

[AsianBlazer]

Jeff,

Check your fuel line hose running from the tank to the pump, it may have cracks in the hose small enough you don't catch with a quick visual, but enough to cause fuel not to pull from the tank consistently. I had the same issue with mine, drove me crazy, turned out to be old, cracked hose from the tank to pump, after I had replaced the entire fuel system. Good luck with that.

Mike

[1955 mancave]

Originally Posted by AsianBlazer

Jeff,

Check your fuel line hose running from the tank to the pump, it may have cracks in the hose small enough you don't catch with a quick visual, but enough to cause fuel not to pull from the tank consistently. I had the same issue with mine, drove me crazy, turned out to be old, cracked hose from the tank to pump, after I had replaced the entire fuel system. Good luck with that.

Mike

X2 i also had the same issue and also had to replace every bit of hose.

[68Timber]

My 79 was doing the same thing, it was cracked hose at the pump.

[kwin]

My suburbans all had detorated fuel pump hoses, one had turned to jelly, two had cracked up, the two with cracks would start if you primed the carb, but would not fire after sitting.

[J Lee]

Ok I will try the hoses and let ya know in a couple days.

[J Lee]

Problem solved! I changed out the lines from the tank to the pump and also the lines from the pump to the carb re-primed it and today after 2 days of not being cranked it fired off with just a few pumps of the accelerator. Thanks for the help. As a side note the main rubber fuel line from the tank to the pump literally crumbled in my hand when I was removing it from the hard line on the frame.

Jeff Lee