Ol'blue

Had a leaky fuel tank. Replaced with used one that I vacuumed out before install. Rig ran fine. Then the crank no start happened. Tested fuel pressure and it was 44psi with key on and dropped to 40psi when turned key off. Swapped out fuel pump relay and no go. Sprayed carb cleaner in to the intake and started up and I drove to work. After work got the no start again. Bought new fuel pump, emptied and dropped tank. Lots of debri found on bottom of tank along with bebri in / on the filter at the bottom of fuel pump assembly. Wow thought I had cleaned the tank, guess not. Proceeded to totally wash and dry inside of tank and set the new pump assembly in. All installed and about 18 gallons of fuel back in tank. Sweet now to go home!!! NOT A CHANCE. The dreaded crank and no start again. Now getting 0 pressure reading. Changed fuel filter and still 0 pressure. Dropped tank and double checked wiring. Pump does turn on and cycle when I turn the key on but not getting any pressure.

Any ideas? Sorry for the long post but trying to get every bit of info I can on here. Thanks guys!!

warthogcrewchief

Is it possible you have a clogged line? Since you said you had all kinds of debris on your filter, I wonder how much, if any, was sucked up beyond the filter. Another possibility would be clogged injectors... but that's a long shot as I don't think all eight would be clogged.

Something that doesn't make sense is that you sprayed carb cleaner into intake and it started. Most carb cleaners retard RPM, as it chokes out oxygen. My only thought is that maybe the carb cleaner might have damaged the mass air flow sensor.

Ol'blue

I actually saw someone else do this to get their 5.7 running. Would it actually ruin the MAF beings I sprayed it on the throttle side of the MAF? I could see it could damage it if I had sprayed it in where it would end up getting sucked into the MAF. not saying that this is not a possibility. Just wondering.
After I installed new pump and it did not start, I did lower the tank enough to reach in and check connections. The smaller line sprayed fuel like it was back pressured when I took it off to check it. That is the return line isn't it? So thinking I had the pump in reverse, I swapped the 2 pump wires. No dice so I reconnected how I had originally had the wires connected.

Ol'blue

Oops!! I actually typed in a reply in the last post between first and last paragraph. Make sure you read the middle quoted paragraph cause it is part of my reply. My bad

Ol'blue

I meant to ask, does a new pump need to be primed? I don't think I put enough fuel in the tank to enable fuel to fill the canister

in2pro

The new pump should prime all on its own as long as there is an inch or so of fuel in the tank....
What brand of pump did you get? I would be suspicious of the new pump....
If you still have access to the old one, you could do a sanity check to see if you get the 40psi back.... if so they you have a DOA new pump....

Ol'blue

The new pump is Airtex. I do have the old pump in which I am tempted to clean up and stuff it back in to see if it will do the trick again. The old one is an AcDelco that has been in the tank for the last 4-5 years.

in2pro

I would recommend going back with the AC-Delco, but I can understand the cost concerns, but in all likelihood, you will be replacing the airtex again real soon...

Ol'blue

That's the plan already, to drop the tank again and return the hunk of junk. Far as I can tell its not working properly. I doubled check all connections and I can hear it run but it won't even push any fuel out right at the port. My guess is faulty right from the get go. The old pump at least registered pressure and gave me some fuel.

Anyone have any similar experiences with a fuel pump? Maybe I'm missing something. Far as I can tell, the 2 smaller wires are for the sending power and ground and the larger 2 wires are for pump ground and power.

Thanks for the replies. I'll go pull out some more hair