Preventing vapor lock

[J-440]

I can drive the car for about 20 minutes with about 10 gallons in the car and then she sputters then dies. Let her sit for 10 minutes and she fires right up. Vapor lock. With 5 gallons it takes about 5 minutes and the car dies. Here's the setup: 440 iron block with EFI, jet hot coated headers, Aeromotive A1000 EXTERIOR mounted pump lower than the tank. -10 feed, -8 return, 2 filters, pressure regulator set at 59psi. All lines insulated starting at the header collectors. After 10 minutes of idling, my headers are close to 600 degrees, and the sending line, return line and fuel rails are 250 degrees. Fuel boils at 205 degrees. I'm ordering some header shielding and maybe some fuel rail shielding. Last resort is ordering an in tank pump. I know most of ya'll are running aluminum blocks but do ya'll still have a ton of heat shielding around your motor? And are fuel coolers worth the money? Thanks.

[Oleyellar]

How did you vent the tank? Do you have an adequately sized vent, You could be drawing a vacuum on the tank causing the pump to cavitate.

[BBC71Nova]

Tried a controller for the pump to slow it down? That's a lot of pump and circulating the fuel isn't helping the heat issue.

[dhutton]

Bad choice of pump imho. That pump isn’t built into an extruded aluminum heat sink for no good reason. It generates a lot of heat. Insulating the fuel lines might actually be making things worse if the pump is heating the fuel.

I would get rid of it and go Vaporworx PWM controlled in tank fuel module. You will never look back.

Don

[J-440]

I’ve got a 1/2” vent line from the top of the fill tube exiting through the trunk floor. I’ve also got a fuel pump controller so the pump isn’t going full blast during cruising. Anyone take a temp reading of their fuel rails? Just curious about the differences in iron and aluminum blocks.

[dhutton]

Originally Posted by J-440

I’ve got a 1/2” vent line from the top of the fill tube exiting through the trunk floor. I’ve also got a fuel pump controller so the pump isn’t going full blast during cruising. Anyone take a temp reading of their fuel rails? Just curious about the differences in iron and aluminum blocks.

What cutback rpm did you set that Aeromotive controller for? What is the reduced pump voltage?

Don

[GregWeld]

One year on the HOF tour we had a Mustang with an externally mounted fuel pump -- fuel would get hot and the car would start acting up or leave her stranded...

Someone suggested filling the truck with bags of ice until a real repair could be done. BINGO --- problem solved.

What am I saying here?? It was all about the pump overheating.... Period. Nothing else wrong with the system.

[J-440]

The controller is set to go full blast at 3500rpm. Voltage is fine. Forgot to mention that the pump temp was at 175 degrees when everything else was at 250.

[dhutton]

Originally Posted by J-440

The controller is set to go full blast at 3500rpm. Voltage is fine. Forgot to mention that the pump temp was at 175 degrees when everything else was at 250.

So you don’t know what your reduced voltage is? Haven’t you measured it?

If the heat sunk exterior of the pump is 175 you can bet the internal pump components are considerably hotter. If I had to guess I would say in excess of 300 degrees. This is based on 35 years of hardware design and countless thermal analyses and calculations....

Don

[J-440]

Voltage is right at 9. I used the instructions on the Aeromotive website.