Overheating Fuel Pump?

[darylfelsberg]

I drove my D about 30 miles had lunch then started back. It was about 95F outside. Then on the highway it had trouble as if it was running out of gas but you would stomp the pedal and it would be fine. Got into town, and it would barely go the it died. Hauled it home on a wrecker. It sat for a day then for fun I started it up and took it for a short spin. Everything was fine.

I have Hervey's fuel pump, new filter, and accumulator. My question is can the heat pump just over heat not work?

[DMCMW Dave]

What's a heat pump?

Sometimes the OEM-style pickup hose will pull shut when very hot, but most of Hervey's fuel pump setups don't bother with one.

[darylfelsberg]

Forgive me. left out the word "fuel" and was thinking heat. And you're right it doesn't have a pick up hose.

[Delorean Industries]

Do you have a heat dam installed to keep the heat from the tank?

[darylfelsberg]

Josh I did not install one......don't think the PO put one in.

[Delorean Industries]

I would say your fuel is getting too hot. Some say it isn't possible but it happens.

[darylfelsberg]

Ok so where can I find a heat dam?

[Delorean Industries]

John Boy is the only seller I know of.

[kings1527]

I had a similar experience a few weeks ago but at the time I was running an OEM fuel pump setup with pickup tube. Same thing as you described, but I'm confident my pickup line was shutting down. After I let it sit for 20 minutes, everything was fine. I have Hervey's dam set up in front but I'm not exactly sure that's the cure, or the cause of the problem. I'm near positive that it's fuel being pre-heated at the hot engine and then being sent back via the return line and dumped back into the tank and heating everything up in there.

I was driving for about 2 hours, some of it uphill on a steep grade (Interstate 5's Grapevine, for anyone who knows) with an ambient of at least 100 degrees and an engine temp consistently 210-220 and AC on Max at 4. Everything was fine until I got off the freeway and cut down on my airflow keeping things as cool as can be. That's when my fuel system wasn't interested in doing that anymore. I picked up the new DMCH pump/sender combo and I'm not anticipating anymore problems. When I got my old baffle system out of my car, I noticed that my pickup line wasn't original to the car but I'm sure it still overheated and flexed. It looked to be in way too good condition to be original.

If you don't have a pickup line, I'm not sure why your car would do what it did.

[Delorean Industries]

I had a similar experience a few weeks ago but at the time I was running an OEM fuel pump setup with pickup tube. Same thing as you described, but I'm confident my pickup line was shutting down. After I let it sit for 20 minutes, everything was fine. I have Hervey's dam set up in front but I'm not exactly sure that's the cure, or the cause of the problem. I'm near positive that it's fuel being pre-heated at the hot engine and then being sent back via the return line and dumped back into the tank and heating everything up in there.

I was driving for about 2 hours, some of it uphill on a steep grade (Interstate 5's Grapevine, for anyone who knows) with an ambient of at least 100 degrees and an engine temp consistently 210-220 and AC on Max at 4. Everything was fine until I got off the freeway and cut down on my airflow keeping things as cool as can be. That's when my fuel system wasn't interested in doing that anymore. I picked up the new DMCH pump/sender combo and I'm not anticipating anymore problems. When I got my old baffle system out of my car, I noticed that my pickup line wasn't original to the car but I'm sure it still overheated and flexed. It looked to be in way too good condition to be original.

If you don't have a pickup line, I'm not sure why your car would do what it did.

The pumps heat up and the cars electrical system doesn't have enough juice to push any harder and the system shuts down via the car stalling out and the rpm relay loosing the tach signal.

[kings1527]

The pumps heat up and the cars electrical system doesn't have enough juice to push any harder and the system shuts down via the car stalling out and the rpm relay loosing the tach signal.

Ah ha. I think I just read something along those lines on a recent thread. As something that's electrical powered and heats up, it requires more electricity to function due to resistance that's created; sometimes beyond the capabilities of the car's system. Thanks for the info.

[Bitsyncmaster]

I've not had the engine shutdown but did have the very loud fuel pump when the gas in the tank gets above 120 deg. I had the hot air dam and the spring in the pickup line so I think it's just cavitation of the fuel when it gets hot. I'm hoping the new DMCH pump does not have that problem.

[dmc4087]

Has anybody heard of a fuel cooler being fitted to a Delorean on the return side of things?

I saw it on a forum before but cant find it now.

[Bitsyncmaster]

Has anybody heard of a fuel cooler being fitted to a Delorean on the return side of things?

I saw it on a forum before but cant find it now.

That would be my post. It was a lot of work so I'm hoping the new DMCH pump cures the hot fuel problem. I have not done any long drives in hot weather yet but since installing that cooler have never heard the pump buzz.

[BABIS]

I'm tryin to develop a fuel heat exchanger to put on the return line of the AC (after the accumulator) in which passes the return line of the fuel...

[Bitsyncmaster]

I'm tryin to develop a fuel heat exchanger to put on the return line of the AC (after the accumulator) in which passes the return line of the fuel...

Here is what I did.

http://dmctalk.org/showthread.php?1560-Fuel-pump-buzzing-cure&highlight=heat+exchanger

[BABIS]

Here is what I did.

http://dmctalk.org/showthread.php?1560-Fuel-pump-buzzing-cure&highlight=heat+exchanger

yes I already knew your setup ;)