NEW BUILD ISSUE WITH FUEL PUMP LOSING ITS PRIME

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I'm late to this thread, but I had something similar happening to my Dart. It would run just fine and then would starve for fuel and quit. I finally found it: the end fitting of the strainer sock on the fuel pickup in the tank was being sucked flat against the pickup line. Removed sock and no more problems. This is likely not your problem since you said you had a filter at the pump so I'd guess you don't have the strainer on the pickup, but thought it might help you just in case.
 
JUST WANTED TO UPDATE ALL

I removed the fuel filter I had installed at the tank. Problem still exists.
I install a sperate tank vent. Problem still exists.
I drove without the fuel cap. Problem still exists.
I confirmed none of my fuel line is against anything hot. Problem still exists.
I believe the mechanical fuel pump being so close to the hose etc. "could" be a problem.

Today, I ordered an electric fuel pump, relay kit, and block off. I hope this works.

Will report back soon.
Thanks all!!!!!
 
johnnydemon said:
JUST WANTED TO UPDATE ALL

I removed the fuel filter I had installed at the tank. Problem still exists.
I install a sperate tank vent. Problem still exists.
I drove without the fuel cap. Problem still exists.
I confirmed none of my fuel line is against anything hot. Problem still exists.
I believe the mechanical fuel pump being so close to the hose etc. "could" be a problem.

Today, I ordered an electric fuel pump, relay kit, and block off. I hope this works.

Will report back soon.
Thanks all!!!!!
Click to expand...
If you have a problem in the tank with the sending unit/sock/pick up then a new electric fuel pump won’t solve it. Check that out before replacing parts.
 
I forgot to point out, the pick up line where the sock minutes on it was notc cut on a diagonal. The particular strainer sock had a plastic end that was flat. Since the end of the two was also flat, and the strainer could move up the tube, then the plastic end basically block the tube.Apparently that’s how they make them now. All you have to do is cut the pick up tube at an angle so the plastic end cannot get sucked flat against it. On mine when I pulled it out of the tank after trying everything else, the flat plastic strainer end had moved up the to to where it completely shut off the fuel.
 

TT5.9mag said:
If you have any pressure drop on the INLET side of the pump it becomes very easy to vapor lock with a little bit of heat. Check the sock in the tank and the filter on the inlet side. And maybe ditch that filter. Make sure the lines aren’t collapsing or sucking air while the pump is running.
Click to expand...
If you're sure your tank is clean you shouldn't need rear filter. But an electric fuel pump pushing thru filter might enable leaving it, if fuel quality is an issue. People put 'Priming Pumps' on when they have this problem, so find one the mechanical pump can draw thru when it's turned off, after priming. Or research to set up a 2 pump system & run it anytime key is on.
 
ANOTHER UPDATE!!!

Replaced mechanical fuel pump with Holley Electric (red)
Fuel tank is newer, Holley and others suggested pre filter which I reinstalled.
Ran car for about 25 miles straight with 0 issues.

Brought it back to the garage and let it cool, ran it again for another 5 miles with 0 issues.

It appears that the problem is resolved.

I really appreciate all of your inputs!!!!!!

John
 
johnnydemon said:
The fuel lines are not against anything hot, however, I really think the lower radiator hose is too close to the fuel pump (3/16") but that's factory. I am just running standard high test pump gas.
Click to expand...
Switch to non ethanol and see if that helps.
 
johnnydemon said:
ANOTHER UPDATE!!!

Replaced mechanical fuel pump with Holley Electric (red)
Fuel tank is newer, Holley and others suggested pre filter which I reinstalled.
Ran car for about 25 miles straight with 0 issues.

Brought it back to the garage and let it cool, ran it again for another 5 miles with 0 issues.

It appears that the problem is resolved.

I really appreciate all of your inputs!!!!!!

John
Click to expand...

Are we to assume the mechanical fuel pump was the issue?
 
Jeremiah (jd) said:
Are we to assume the mechanical fuel pump was the issue?
Click to expand...
Yes, we would have to assume that the mechanical pump was the issue. I truly think that the pump was getting way too hot being only a 16th" from the radiator hose. I do have an aftermarket radiator that may have place the lower radiator hose slightly closer to pump??

I never changed any fuel line routing, only broke the existing line in rear of car for new electric pump. I basically reconnected the inlet and outlet fuel lines at the existing mechanical pump.

I just drove about 25 miles tonight, burning some rubber and having fun. No issues at this point.
 
Fuel tank needs that vent , install a hose above the tank then put a one way valve on the end of the hose so air only goes in and fuel won't come out when you fill up with fuel.
 
johnnydemon said:
ANOTHER UPDATE!!!

Replaced mechanical fuel pump with Holley Electric (red)
Fuel tank is newer, Holley and others suggested pre filter which I reinstalled.
Ran car for about 25 miles straight with 0 issues.

Brought it back to the garage and let it cool, ran it again for another 5 miles with 0 issues.

It appears that the problem is resolved.

I really appreciate all of your inputs!!!!!!

John
Click to expand...
How about a pic or description of where you mounted the pump? Getting ready to convert my 340 Sport to an electric pump and looking for mounting suggestions.
 
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