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Posted by: akellym May 11 2007, 02:47 PM

Okay, so last week the car starting running crappy. checked the fuel pressure, was jumping around then dropped to 0(I have carbs running at 3lbs). So yesterday I installed my brand new back up pump. I was tunning the carbs, everything was going great. After 20mins the car start running crappy again, look at the fuel pressure it was doing the same thing again. Car died, fuel pump wasn't making any noise, checked and it was flaming hot! I have a primary and secondary fuel filter both are clean. Called Mallory they said it must be a bad pump, send it back. Fine, so overnight a new pump install it, this time checking it often. It starts getting hot, what the flip! I can hear the pump changing in pitch, so I think must be elec. I'm getting 13.5v at the pump. My volt reg is rather hot so I put in a new one, now I'm getting 14.2v at the pump. Still getting hot, change the relay( it was hot also) still getting hot!

some pics of the set up.

Any suggestions?


Attached image(s)

Posted by: TROJANMAN May 11 2007, 02:52 PM

Out of curiosity, do you have a stock pump you can compare to?

Posted by: akellym May 11 2007, 02:54 PM

FI pump? Yes I do have, not sure what you mean thou....

Posted by: Travis Neff May 11 2007, 03:09 PM

Maybe you have a kinked fuel hose or clogged filter/sock in the tank?

Posted by: akellym May 11 2007, 03:21 PM

Just check tanks is clean and so is sock. I'm running brake line for fuel except where you see the stainless.

Posted by: akellym May 11 2007, 04:19 PM

just tried running a ground direct, was using a harness ground wire. Still no change.

Posted by: yarin May 11 2007, 05:08 PM

Just a wild ass guess, but try to lower the elevation of the pump to tank level. This way the pump has to do less pulling. no?

Posted by: Demick May 11 2007, 05:23 PM

Fuel pumps aren't really capable of pulling at all. It needs to be gravity fed from the tank to the pump. If your fuel level in the tank drops below the level of the pump, it will starve.

Fill your fuel tank and see if the problem goes away.

Demick

Posted by: Demick May 11 2007, 05:25 PM

....and since most fuel pumps that I am familiar with are cooled by the fuel ----- no fuel, no cooling.

Posted by: akellym May 11 2007, 05:26 PM

The photo doesn't show it, but the pump is in the front trunk about 1" off the bottom.

This problem is recent.

Posted by: So.Cal.914 May 11 2007, 05:47 PM

QUOTE(akellym @ May 11 2007, 02:21 PM)

Posted by: akellym May 11 2007, 06:30 PM

3/8 and the stainless braided hose is -6 which I think is a little bigger than 3/8(not sure).

I just ran it 20 miles(hard) stop at around 10miles check the pump seemed normal as far as heat goes. Got back and it seem about the same. If it's not raining tomorrow I'm going puts some miles on and see how it does. My concern is if it run at normal temps on the hwy, what will happen if I were stuck in traffic?

These are the things I have done to try and correct the promblem.

1. new pump and made sure all fuel filters were clean-didn't help
2. new volt reg-didn't help(I'm showing an increase in volts from 13.2 to 14.5)
3. new fuel relay-didn't help
4. cleaned all grounds-didn't help
5. ran new ground direct-didn't help
6. checked fuel flow and carbs

Posted by: Aaron Cox May 11 2007, 06:38 PM

-6 means 6/16" or 3/8"

just for what its worth

Posted by: TROJANMAN May 11 2007, 06:39 PM

good luck

Posted by: Aaron Cox May 11 2007, 06:39 PM

QUOTE(TROJANMAN @ May 11 2007, 05:39 PM)

Posted by: TROJANMAN May 11 2007, 06:49 PM

you're quicker than i am. i edited that when i realized my mistake, and before your last post
you must have quoted me during my edit.
and given the fact both of our posts have the same time stamp, i'd say your pretty damn quick

Posted by: kwales May 11 2007, 07:07 PM

Heat means more work than expected, more DC power supplied than expected, too small of a power line, or a failing motor.

Gotta load of crap gas?

I had a Vanagon take on about 3/4 of an inch of crud in the bottom of the gas tank in one fillup.

Pump motor heated up and whined due to excess work pulling through the filter. Took over 45 mins at the car wash to finally blow out all of the crap. That was when our ever faithful oil companies knew they had screwed up the gas mix so it would ruin the fuel tank sensors and shipped it anyway.

Can you rig up a bypass and pump the the gas right back into the tank filler without heating up the pump? If you can, the problem is between the pump and the carbs.

Ken