Fuel Pump Possibly Dying from Heat Stroke

[Ahwahnee]

With the local temps getting into the teens this week I have encountered a recurrence of a problem I had experienced last summer. On lengthy in-town drives (not much speed, lots of stop & go) the engine dies only to restart after a few minutes rest. Listening closely I conclude the fuel pump is not running.

The respite is brief and it stalls again. The only ways to get extended relief were 1) a much longer cool-down 2) filling the nearly empty gas tank 3) wrapping a wet towel around the fuel pump.

Hence my poll question.

I recall that the fuel pump is cooled in part by the gas moving through it, probably also cooled by air moving past it. But when the air is, say, 120° (one foot above hot asphalt) and the fuel is perhaps 90° or so (that's a guess) -- will wrapping some insulation around the pump make things better or worse?

I'm guessing that the pump itself generates heat as it runs.

BTW, it is an '84 WBX, fuel filter (square white one) is fairly new as is the fuel pump.

Thanks for any theories or other things I have missed.

[joseph928]

On my 84 I went with the late model filter, bigger more flow. That seems to help over the little one you use. I did that when in Denver when the temp came close to 100 it helped. Also keep the tank full, with the FPR putting fuel back into the tank mass is good. You could put a small guard under the pump to block radiant heat from the pavement. But air flow around the pump is good!
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1987 syncro westy tin top sun roof , GW2.3, rear locker, decoupler, Gary Lee tire rack & winch mount, lift, south african grill, big brakes , rhein alloy ,15 BFG AT, Fiamma 10 foot awning ,140 watt rear 85 watt front solar , mppt, truckfridge, automatic fire extinguishing system, tencent oil cooler, And a RMW SS exhaust! - 1971 bug convertible 1776 engine- 2010 Subaru turbo - 1993 Toyota 4x4 truck - 1999 Harley 95 CI, big bore, Andrews cams . Also 80-84- vans. Stock 65 sunroof bug.

[insyncro]

We add a fuel cooler if the pumps can't handle the heat at the track.

[insyncro]

If the pump is getting that hot, it may be binding and heating your fuel.

My eBay $39.00 fuel pump now has 80k miles on it and is cool to the touch while running.

Just as a reference, I have brand new Pierburg pumps that are fully covered with a very thick rubber cover.
They cost $300+, go figure?

[Vanagon Nut]

I don't know if this'll help, but my FP gets much noisier in higher ambient temps. My thinking is that the fuel gets warmer. In my case, noise is likely pump cavitating.

Pump et al was new not long ago. Bosch pump, smaller outlet tank, no pre filter.

Neil.
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1981 Westy DIY 15º ABA

1988 West DIY 50º ABA

VE7TBN

[purplepeopleeater]

mine gets whiney when its hot out....I have thought about loosing the prefilter to increase flow, everything is new so my theory is I shouldn't have to worry about rust killing the pump.

[markz2004]

[randywebb]

fuel expands with heat - I forget the coefficient of expansion tho

a new pump is good preventative maintenance
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1986 2.1L Westy 2wd Auto Trans.