Fuel Pump or Air leak or Other HELP

[Bascom123]

I have a 66 mustang, 289. I had the factory style fuel pump but started having troubles with starting, specifically after starting and then stopping while the front end was on an incline.

I installed a fuel filter (glass) and noticed that the gas would not come up. So i pushed it so the front end was downhill and voila it starts right up.

I know always park downhill, bet lets be serious here I need to figure this out.

So i replaced the fuel pump with a Holly (new). It does the exact same thing. Also replaced the fuel line from the metal line exiting the fender to the pump, then from the pump upwards to the carb.

When it runs the fuel filter is full, stop it and the gas runs out back to the tank. What can I do to fix this? Do I have an air leak (i dont smell gas or see any leaking), is it the pump, carb? Can anyone help point me in the right direction?

It would seem to me that the fuel filter should stay full and not empty.

Any help at all would be appreciated.

 

[iskwezm]

can a check valve be used????

 

[68 Coop]

How long do you park the car??? Mine will do that too, if it sits a couple days. It vapor locked on me once this summer, took it all night to cool down enough to start right. Truthfully, I don't know what causes it, I've heard it's normal???

 

[Bascom123]

Update

Yeah it could be 10 minutes, like it could be 2 minutes. Does anyone out there have a similar setup with a glass filter. If so does your fuel leak back through the pump to the tank? or does the filter stay full?

 

[jbuening]

I have the cheapo glass filter from autozone and it empties after sitting a day or two. But, my pump pushes the fuel up within a few cranks so i don't have problems starting. Try opening your gas cap and see if that helps at all. It may not be venting right and causing a slight vacuum in the tank??? Never heard of it but you never know.

 

[tos]

It sounds like your pump is worn out. The fact that when you point it down hill helps I think is because gravity and the weight of the fuel in the tank are helping out the pump. Your pump should also hold pressure for quite some time and not allow fuel to bleed back to the tank. I dont know about this pump but some have a one way (check) valve for that reason.

 

[Bascom123]

follow up

yes, its a new Holly fuel pump. I had a new ford knock off prior to that it did the same thing. So i bought a holly.

Anyone know of a one way valve that I could install?

 

[dbm]

Where is the fuel pump located? It should be located as close to the gas tank as possible as it should push the gas not suck it. You might also want to try to hook up a regulator , for like 5-6 psi (I think) If I am wrong someone will correct this and tell you how many psi.

 

[Bascom123]

fuel pump

It is a replacement mechanical fuel pump not a electric pump. i did some looking online for a check valve and have not really found anything that could work. Anyone got a suggestion?

 

[Kriek]

Any updates?

 

[Bascom123]

Updates

None as of yet, I have onmy agenda this week to try it with the gas cap open to see if a vacuum is being created int he tank. however I also noticed my fuel filter was a bit loose (its a glass screw type) yet no gas leaking. So i have tightend that. I will post again later this week once i get a chance to try it out.