electric fuel pump quits in hot weather.

Posted By: cornucopia

electric fuel pump quits in hot weather. - 07/12/12 03:21 PM

I have a brand X truck with EFI and a rail mounted pump. it was a new,NAPA brand pump I installed 500 miles ago. all has been well till yesterday; we got a HOT bunch of weather! with the air temp at 102 degrees.

I drove it about one mile and noticed that it was a LOUD buzzing noise. 2 miles later it quit all together. I went to retreive it this morning with the outside temp now around 68-70, and it works fine! why would the heat make it quit? just a crappy pump?

Posted By: Mopar_Rich

Re: electric fuel pump quits in hot weather. - 07/12/12 03:43 PM

Full return or dead-head fuel sysyem?

Posted By: Andrewh

Re: electric fuel pump quits in hot weather. - 07/12/12 04:32 PM

I have had that happen when I had the pump too close to the exhaust. would take a dump, then after the car was off 20 to 30 min, it would work again.

something inside just can't take the heat and kills some tollerance is all I can figure out.

I replaced it but moved it away from anything hot, and it has been fine since.

could just be a crappy pump, but I would look around and see if something is too close to it.

my problem was I installed the pump before exhaust and the exhaust shop decided to see how close they could route the exhaust to it.
never noticed or looked till the car died.

Posted By: cornucopia

Re: electric fuel pump quits in hot weather. - 07/12/12 04:39 PM

Quote:

Full return or dead-head fuel sysyem?

return to tank.

Posted By: cornucopia

Re: electric fuel pump quits in hot weather. - 07/12/12 04:41 PM

Quote:

I have had that happen when I had the pump too close to the exhaust. would take a dump, then after the car was off 20 to 30 min, it would work again.

something inside just can't take the heat and kills some tollerance is all I can figure out.

I replaced it but moved it away from anything hot, and it has been fine since.

could just be a crappy pump, but I would look around and see if something is too close to it.

my problem was I installed the pump before exhaust and the exhaust shop decided to see how close they could route the exhaust to it.
never noticed or looked till the car died.

this rig is a straight 6. exhaust is on the OTHER side. totally stock rig. the original pump went 125K this one is kaput at 500 miles.

Posted By: Andrewh

Re: electric fuel pump quits in hot weather. - 07/12/12 05:21 PM

then, just a crappy pump.
might see if it is under warranty. otherwise msd sells a generic that works quite well. also walbro.

Posted By: cornucopia

Re: electric fuel pump quits in hot weather. - 07/12/12 07:38 PM

yeah, thats what I thought...crummy pump. I thought NAPA had better parts? oh, well. live and learn. thanks guys!

Posted By: Challenger 1

Re: electric fuel pump quits in hot weather. - 07/12/12 07:49 PM

I bet it's not the pump, it's the plumbing. It don't have a large enough inlet line to feed the pump during hot weather. The inlet should always be bigger than the discharge on any pump. Even if your inlet is bigger than the discharge now, it's either not big enough still or the pump is mounted wrong.

Gas is one of the most difficult things to pump and most people don't understand that and blame the pump.

Make sure if possible that the pump is gravity feed with a large inlet line and it won't do that. Is that always possible? No not always without a custom tank.

Posted By: Challenger 1

Re: electric fuel pump quits in hot weather. - 07/12/12 09:01 PM

Quote:

I have a brand X truck with EFI and a rail mounted pump. it was a new,NAPA brand pump I installed 500 miles ago. all has been well till yesterday; we got a HOT bunch of weather! with the air temp at 102 degrees.

I drove it about one mile and noticed that it was a LOUD buzzing noise. 2 miles later it quit all together. I went to retreive it this morning with the outside temp now around 68-70, and it works fine! why would the heat make it quit? just a crappy pump?

I forgot to mention gas vaporizes real easy when the temps go up and the plumbing becomes very important. Gas can not be under a vacuum, it will turn to vapor and the pump can't pump vapor, that's why the sound changed. All this is why the fuel pumps are in the gas tanks nowadays.

Posted By: RapidRobert

Re: electric fuel pump quits in hot weather. - 07/12/12 09:08 PM

Quote:

I forgot to mention gas vaporizes real easy when the temps go up and the plumbing becomes very important. Gas can not be under a vacuum, it will turn to vapor and the pump can't pump vapor, that's why the sound changed.

Good info. I wonder if he eases the restriction on the inlet side if that will take care of it

Posted By: Challenger 1

Re: electric fuel pump quits in hot weather. - 07/12/12 09:42 PM

Quote:

Quote:

I forgot to mention gas vaporizes real easy when the temps go up and the plumbing becomes very important. Gas can not be under a vacuum, it will turn to vapor and the pump can't pump vapor, that's why the sound changed.

Good info. I wonder if he eases the restriction on the inlet side if that will take care of it

Yes