Pro Comp fuel pump

[PeteF]

Today I used AAA for the first time in my life. The ProComp mechanical fuel pump that I installed about a year ago on my 351W gave up about two miles from my house. Upon disassembly, I found the diaphragm rod severely worn through about 95% of the way, then snapped in two. No other obvious signs of wear or misalignment to the engine, so the problem looks completely within the pump. I installed a new Holley pump, and we're on the road again. I read somewhere (maybe here) that ProComp products are made in China. I can't tell if this was a misassembly problem or just a poor design. It does look cheaply made, based on the internals, compared to other pumps I have seen in the past. Beware ProComp fuel pumps......this type failure gives no warning whatsoever. Fuel pressure gage reading zero made diagnosis easy though.

[bobcowan]

As far as I can tell, ProComp is off shore copies of American products. I don't buy anything from them.

[Tommy]

Wait a second. Today's not April 1st is it? How could your mechanical fuel pump have failed after all the posts I've read here on the forum describing them as simple, reliable, fool proof and highly superior to electric fuel pumps? You don't suppose the quality of the pump matters more than whether or not it's mechanical or electrical, do you?

[Ralphy]

Tommy,
What pump and where did you mount it, if I may ask?

Ralphy

[Tommy]

Ralphy,
Let me start by saying that my car was optimized for track use and is not as civilized as some. For example, it sits lower than most and the trunk is not finished for looks. That said, my fuel pump, pressure regulator and large fuel filter are all mounted in the trunk. The pump is a Holley Red that I modified when I added the pressure regulator. I put a much stronger pressure relief spring in the Holley Red so it's internal pressure regulator would not open before the external pressure regulator could work. ... I've had the car configured like this since 2005 and run it at several open track events with no problems.

You may be interested to know why I added an external pressure regulator with a return line to the fuel tank. Without it, I discovered that on hot days at track events, the Holley Red would get hot enough to vaporize the fuel circulating through its internal pressure regulating system, causing vapor lock. The external regulator lets fuel pass thorugh the pump so quickly it won't vaporize even on very hot days.

[Ralphy]

I know you race, however I didn't think about your trunk being gutted.

Thanks,
R