fuel questions

[sgt1022]

I have a 71 c10 w/350ci edelbrock carb Holley 110 gph blue pump through regulator at 4 psi. With braided-6 line. After I drive for an hour or so in traffic my regulator starts dropping pressure when I'm at idle. The problem has left me stranded twice. I can loosen a fitting and in a couple seconds fuel starts flowing again and truck starts immediately. My fuel lines are a fair distance away from exhaust heat. I do not have a return line.

[dwcsr]

several things come to mind
How are you checking pressure if its liquid filled gauge under the hood get rid of it and use a dry gauge then re check the pressure.
Clogged pickup intermittently collapsing the fuel line. when you loosen the line the vacuum is released.

bad pump.
bad filter. where is the filter in the system? before the pump or after. Temporarily run it with out the filter after you make sure you don't have trash or a rag in the tank.

[sgt1022]

I have an Autometer sport comp dry gauge mounted on my cowl. fuel tank and pick up is brand new. Steel line coming out of tank into braided steel -6 line. Fuel filter is between tank and pump. Fuel pump is only a month old powered through a relay.

Could the fuel be heating up because there is no return line and causing a vapor lock?

[geezer#99]

Do you have a vented gas cap?

[Dustint]

Assuming your fuel pump is electric, where is it located? Having the pump located too far from the tank or closer to the engine could cause your problem, pumps are designed to push the fuel, not pull. Have seen several cases where this causes a vapor lock type of situation when things start to get warm or on a really hot day.
May not be what you have going on, but certainly an easy fix if it does need relocated closer to the tank.

[Speedbumpauto]

IMO, you would be better off with a red pump and 5-6 pounds of pressure if you're not using a return. That 18 psi pump is working pretty hard for the 4 pounds of pressure, but that's probably not the problem. Like said above, pump location is very important.

[Sean714]

I've heard with some fuel pumps if they are close to the exhaust they will heat up and make the pump turn off or do weird stuff. If this is the case just get some exhast wrap and wrap it up where it's close the the pump. Problem solved, this happened to my uncles roadster, not sure if this applys to your case, just a thought I had.

[OrrieG]

Are you using ethenol fuel (10% around here)? We had an Accord when they first started using the e fuel that would vapor lock when the temps went over 95 and the engine sat hot. Switched back to regular gas and did not have any problems. That was in the 90's. New engine computers are set up to manage the fuel better.

[sgt1022]

I/M still running the stock fuel tank behind the seat. the pump is no more than 12 - 14 inches away from tank. my exhaust is run outside of my framerail. The pump is mounted on a fabbed bracket to allow air to circulate between the rail and the pump.

I went with a blue pump to build a fuel system to handle increased HP in the near future.

Gas cap is the stock style. I do have the tank for Evaporative emission control (EEC).

Would a return line help to maintain and even fuel temp?