the Saga continues......Not enough fuel getting to my carb on my 68 big block., so I replaced the mechanical fuel pump with a new one. oddly enough it worked "intermittently" sometimes there's fuel in the filter, sometimes not enough...this could be a push rod problem i realize or a problem with the cam that drives the push rod, but I went ahead and put a 3-7psi electric fuel pump (edelbrock) on it thinking that this will fix the problem for good......No Such Luck! Initially it looks like it's great, fuel fills up the clear filter.....then I drive it and it's hit or miss... Sometimes it works just fine. Sometimes too much fuel pushes through the carb and I end up with gasoline pooling on my intake. Other times the carburetor runs out of gas because not enough is being pumped through the filter to even see. I have blown the line from the pump back to the tank with an air hose and it's clear. The "sock" filter in the tank looks perfect, and when you disconnect the pump, gas runs out of the hose everywhere. The frustration of this is killing me. I am in the process of having Lars rebuilt a quadrajet for my car, but If I can't get fuel to it, it's not going to matter anyway. It seems like it should be a simple thing......electric fuel pump, pumps gas to the carburetor, right? Does ANYONE have a clue as to what might be the problem here? Has anyone experienced this before?? Any help at all is appreciated!

 

Other than the filter doing strange things, what exactly is wrong with how the engine runs?
What carburetor is on the car now?
Have you done a fuel pressure test?

 

I think I would disconnect the fuel line to the carb right after the filter connection. Then using a couple feet of hose, connect that and run that hose into a gas can. With battery fully charged, see if that pump can do its thing for 60 seconds and fill your gas can. Is it steady pressure? Clogged? Hesitant?

 

runs out of gas when I step on the throttle. I've not done a pressure test. I could find an inline pressure gauge and see what it is. Im not sure what it's supposed to be.

 

I'll try this and see what happens

 

Do you have the canister filter with in - out - return connections? - I'd be inclined to check this out for blockages (a piece of crud moving around inside?). Has the rubber section of fuel line over rear chassis rail perished?

 

I realize those glass or plastic see-thru fuel filters are very helpful in situations like yours. But I just cringe every time I see one. I don't trust them due to the fire hazards and I don't trust them for 100% fuel delivery. I believe the glass distorts how much gas is REALLY going through it. Not as much as one thinks sometimes.

 

If you mean it hesitates, you could have a bad accelerator pump in the carburetor or you have a float problem.
You still haven't mentioned what carburetor is currently on the car?????
A stock pump should put out about 6 PSI.

 

so this is a non #'s matching car. The ONLY filters in the syster are the "Sock" filter in the tank, and then the filter right up by the carburetor. The only rubber line is where it goes into the fuel pump and out of the fuel pump to the carb. There IS a 6" section of rubber line in the rear of the car by the frame. Looks like it would be a good place to put a filter.

 

YOur vent in the gas cap could be plugged preventing gas from moving, then burping and getting too much gas. IF you can replicate this in your driveway try openning the cap while you are experiencing the problem. I had your same symptoms on an old motorcycle

 

More then likely, the mechanical fuel pump is simply not keeping up....and trying to flow THROUGH the pump with an electric really doesn't work well. If its a stock type pump from a part store, then ditch it.... Either get a factory AC Delco pump (if you can find one) or go to an aftermarket mechanical.

I just went through this same crap on my dad's 355" 70' Nova, new build, new fuel pump, new lines... It would roll over at 4800 rpms in 2nd gear... I T'd in a fuel pressure gauge and ran it into the car (temporarily) and it would drop to 0-2 psi at 4800 in 1st, then 0 at 4800 in 2nd. Went to a Summit brand mechanical pump that is 80 gph, no regulator or return line needed... Now it holds 4-5 psi into 3rd. I've had it as high 6300 rpms in 2nd. No issues so far.

 

thanks...I might just have to do that.