Fuel filter keeps running dry, car stalls

[Sonny]

I’ve had this issue for a month now since getting new carb. First sign: I went to accelerate over an inclined road (train overpass) and all of a sudden air fuel gauge goes way lean, car is stumbling, I’m pedaling it the whole way up, levels out and clears up. So I thought-fuel delivery issue- added a 3/8” tee, a second 3/8” line and made the Edelbrock avs2 650 a dual feed Carb. Problem happens again on flat road and I notice the fuel filter is bone dry. Took 30 min to restart and prime line. Next logical assumption- failing fuel pump, so I buy and install a new edelbrock fuel pump. Happened again today, took 30 minutes to reprime the system again. Same thing, no line pressure or fuel in filter. So I have the following new stuff:
Fuel pump
Avs2 carb
Rpm air gap intake
ignition system
fuel hose and filter
Fuel tank and sender
Original stuff:
5/16” fuel lines from pump to tank
Original tank vents
Also thought fuel gauge was lying, it wasn’t. Happens at 1/4 tank and at full.
Here is fuel line chart:
5/16” sender line in tank
5/16” fuel hard line (old)
5/16” adapter on “in” side of pump
3/8” pump outlet and 3/8” all the way to carb. It’s been a rough car month. Open for any suggestions.

 

[1967coronet440]

Sounds like the fuel could be boiling?

 

[Jcharger]

Have you checked the pushrod that drives the fuel pump?

 

[WileE]

How is the sock on the pickup ? Are the vent tubes clogged ? What type gas cap are you using ?

 

[Sonny]

How is the sock on the pickup ? Are the vent tubes clogged ? What type gas cap are you using ?

Sock is brand new. Original rusty cap. I think the vent tubes are rough. Gonna pull those off and check.

 

[Sonny]

Have you checked the pushrod that drives the fuel pump?

It’s a small block 360. It doesn’t have a rod, just an offset cap bolted to the cam/timing gear.

 

[hashmaker]

Vapor lock or boiling fuel is something to consider, other things could be: tank vent plugged or not sufficient, hole worn into that original line (or any where)allowing air to be sucked in, fuel sending unit screen plugged or restricted, fuel pump push rod worn and unable to keep the pump working fast enough.

 

[threewood]

Have you verified pressure loss with a pressure gauge?
I would suspect the fuel pump pushrod. (Just read 360, no pushrod...disregard )
Checked float levels?
I had to return an Edelbrock high volume mech pump because my 800cfm carb was running dry at wot.

 

[hashmaker]

If it does not have a fuel pump push rod then the cam lobe or what ever drives it is worn??

 

[PP1RT]

Piece of hose on the suction side of the pump collapsing internally?

 

[Sonny]

Vapor lock or boiling fuel is something to consider, other things could be: tank vent plugged or not sufficient, hole worn into that original line (or any where)allowing air to be sucked in, fuel sending unit screen plugged or restricted, fuel pump push rod worn and unable to keep the pump working fast enough.

Wondering how fuel boiling would cause an empty fuel filter ? Not being rude, just an honest question.

 

[Sonny]

I just drove the car 30 min ago and filter is bone dry.

 

[WileE]

Assuming the fuel pump is good, it's not getting fuel from the tank from air leak in line, clogged sock, clogged vent, bad vented gas cap. Pickup could also be cracked, allowing suction of air.

 

[moes]

I would disconnect the fuel filter hose on the carb side, put the hose in a gas can (get someone to turn the motor over and you can watch) to see how much gas is flowing in to your filter and out.

 

[dieseldazzle]

Id install a pusher pump back at the tank but its probably pin holes in hard fuel lines Crack in the plastic fuel filter and or cracked or loose hose fitting etc on the pickup side or just plain and simple bad fuel pump on the suction side.

 

[Sonny]

View attachment 575307
Wondering how fuel boiling would cause an empty fuel filter ? Not being rude, just an honest question.

Well I just tried to start the car and it’s “flooded”. Fuel splashing out AND I can hear it boiling! I have a 1/4” gasket I’ll put on the base and see if that helps. Good call “hash maker”.

 

[Ron H]

Not to state the obvious, ok I will, and as has been posted...the filter getting dry means no fuel reaching it so a pressure check should be done and could do with the front end raised up on a jack (following that you said it happens on an incline only)? That filter looks unusual to me anyway pretty small as is its location...is that the stock setup? Seems the typical arrangement is horizontal nearer to the carb. Did you try putting in a different fuel filter? Hose should be fuel grade. Check the line from the new tank to the pump ensuring there are no kinks or hard bends. I reckon the sending unit was sealed fine when you put that in? If not you would likely have smelled gas around the rear of the car.

 

[lewtot184]

I installed a return line and the fuel filter isn't dry anymore. also look to make sure the tank has a good vent.

 

[dadalis]

I have done the similar replacement strategy on my jeep and in the end found the line from tank to the carb was plugged like an artery full of cholesterol.

 

[BBishere2]

I’ve had this issue for a month now since getting new carb. First sign: I went to accelerate over an inclined road (train overpass) and all of a sudden air fuel gauge goes way lean, car is stumbling, I’m pedaling it the whole way up, levels out and clears up. So I thought-fuel delivery issue- added a 3/8” tee, a second 3/8” line and made the Edelbrock avs2 650 a dual feed Carb. Problem happens again on flat road and I notice the fuel filter is bone dry. Took 30 min to restart and prime line. Next logical assumption- failing fuel pump, so I buy and install a new edelbrock fuel pump. Happened again today, took 30 minutes to reprime the system again. Same thing, no line pressure or fuel in filter. So I have the following new stuff:
Fuel pump
Avs2 carb
Rpm air gap intake
ignition system
fuel hose and filter
Fuel tank and sender
Original stuff:
5/16” fuel lines from pump to tank
Original tank vents
Also thought fuel gauge was lying, it wasn’t. Happens at 1/4 tank and at full.
Here is fuel line chart:
5/16” sender line in tank
5/16” fuel hard line (old)
5/16” adapter on “in” side of pump
3/8” pump outlet and 3/8” all the way to carb. It’s been a rough car month. Open for any suggestions.

When it runs dry at the filter, have you tried removing the gas cap and seeing if there is vacuum at the tank?