Fuel System Bench Testing

Today my dad stopped by to drop off the new rear floor panel and to take the nose parts off to paint. We took a few minutes to assemble a rig to test out the new HPD Kit's in tank fuel pump and regulator.

Good thing we did. After a few minutes of head scratching to figure out how to easily and safely apply power to the pump, we got it working nicely. The pump ran and developed pressure (too much - but more on that later)...

After a brief pause to get everything tight and leak proof, we found that the pump was working, and that the bypass was questionable. It seemed to go into bypass mode at about 68-69psi. I could hear fuel cycling back into the tank, but the pressure was not setting at the correct 55psi.

So I took it all apart (several times) and took out the regulator from the housing. I reseated it and tried again. Same result - 69psi.
So e-mails off to HPD. The good thing is that the cell is not installed in the car yet, and I can figure this out over the next couple of days. This would really suck if I was at the track...

Pictured above is how I did the test. I used the HPD wiring harness to supply power. Plugged in the fuel pump connector, and jumped the red wire labeled "Fuel Pump" to the positive battery terminal. Then I connected the ground wire on the harness to battery ground and 'buzzz" the pump powered up and begin to do it's thing.

To test the pressure I made up a short hose with AN4 fittings on each end. I connected this to the HPD supplied inline filter assembly. In place of the fuel test port, I screwed in a Marshal 0-100psi pressure gauge. (This same exact gauge has been used on my father and Steve Oseth's cars and read 55psi, so I am fairly sure it is accurate).

If you have any thoughts on the excess pressure please send me an e-mail (smaisey@cwf.org) or post a comment here.

Thanks,
Sean