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MG MGB Technical - Holley fuel pump issue?

My car is set up with a Holley "blue" electric fuel pump to cope w/Weber carb pressure requirements.
All was well until I got stuck in a lengthy traffic jam(about 45 mins) in 80deg. temp. last weekend. The car idled/ran at low speed for a long time, then simply sputtered and died. I noticed at this point that the fuel pump was extremely hot...and I could not find anything else wrong. I conjectured that the super-heated fuel pump was not running enough fuel through, and had somehow created a bit of vapor lock. After waiting about 20-25 mins.,the pump cooled, the car fired and ran great for the remainder of the journey.
Today, same thing happened, only this time the car had been running fine for about an hour. Stopped for breakfast (one hour); started car again, drove about 100 feet, then motor sputtered, stalled, and wouldn't run. Let it rest for about 10 mins, car started, drove 30 mins home with no problem. The temperature today ranged from 60-about 80deg.
So...am I on the right track? Can the fuel pump become "weak" and susceptible to high temps/vapor lock, etc. Note that I drove it on track days/autoxes etc. last summer in 100-plus temps with no fuel delivery problems! Also, the fuel pump is about 7 years old.

Thanks in advance for your help,
Martin
Martin Connolly

I think you are on the right track - but for the wrong reasons. These pumps are designed to push more fuel than is generally needed for SU/weber carbs. That is why most of us who run them use pressure regulators to step down the pressure. Idling for long periods probably did overheat your pump because not enough fuel was moving through the pump to cool it off.

The only way I see one getting vapor locked is if the pickup tube is out of the fuel - tipped on the side of the road for example. Other than that I don't think "vaporlock" is really an issue as the fuel is generally almost directly above the pump.

The other thing it might be is flooded carbs. Idling for long periods might jiggle the inlet seat enough to allow overfilling the float chamber when idling for excessive periods with a higher than recommended pressure pump.

Just my ideas, might be all wrong.
C Holm

C-
Thanks, good suggestions, however, I do have a regulator, set at the prescribed 3 psi for Webers.
Martin
Martin Connolly

I think the "blue" pump is overkill. I use a "red" pump on my V8, as do most V8ers. Have you checked the filters ? Barrie E
Barrie Egerton

Yes, filters appear ok. What is the difference between "blue" and "red" pumps?
Martin
Martin Connolly

The Blue pump(HLY12-802-1) is rated 95 gph @ 7 psi

The Red pump (HLY12-801-1) is rated 71 gph @ 4 psi
C Holm

This thread was discussed between 28/05/2007 and 29/05/2007

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