Fuel Delivery issues

[85MustGT]

Just pulled out the gas tank. Yanked the sending/pickup/unit. Everything looks good. The filter on the end of the pickup is brown and looks OK, is it suppossed to be brown? There doesn't appear to be junk in the tank as I expected.

My car runs out of gas intermitently. It runs for great for about the first 10 or 15 minutes then stalls. I paid to have an electrician check it out, at first I thought it was electrical. I put a glass fuel filter on and everytime it stalls the filter is bone dry. Otherwise it is 75% filled with gas.

I replaced the fuel pump and gas filter. I have 6.5 psi. I have a new Holley 80457S. (it had this problem with the old carb as well)

What next? Why is my car running out of gas? I will replace all of the hoses, If the gas line on top of the tank had a small crack could the fuel pump been pumping air rather than gas?

I was thinking of buying an electric fuel pump, mounting it low and near the tank so it pushes rather than sucks.

Any advice?

1985 Mustang GT
5speed
8.8 rear with 3:55s
Holley 600

[PKRWUD]

Your last idea is your best. If there was a crack in the fuel line, you would smell fuell, and it wouldn't ever be able to build up sufficient pressure. You might have debris in the fuel line, and it would be wise to blow the line out with compressed air. The charcoal cannister and fuel return lines may be clogged, which could lead to vapor lock symptoms, similar to what you describe. Anytime the tank is down, always change the in-tank filter. It's cheap and practical. I would look into installing an in-tank electric pump with an external regulator.

Lastly, you should install an inline fuel pressure gauge, as close to the carb as possible. This will become an excellent tool for future fuel system diagnosis and tuning.

Take care,
-Chris

[85MustGT]

Thanks PKRWUD the car runs great. I did not get a chance to install a fuel pressure gague however gauges are in the future.
It is amazing how much performance I can get cheap.
1985 Must GT 1500.00
8.8 rear 3.55s 250.00
Holley Carb 210.00
Struts/shocks 250.00
Brakes 100.00

For less than 2500.00 I have a nice looking well performing vehicle. I live in San Diego where there is lots of rice burners and I would be hard pressed to find a better performing car for the money.

BTW gears are so awesome!