Ok, I figured out what happened to the fuel pump. I broke it, but not the way I thought in last post.

I now believe that the pump was not leaking when I first tested it. To minimize fuel spillage and to keep from having to remove the entire assembly to tape the pressure gauge threads, I used the ubiquitous ViceGrip pliers to pinch off a line in the spot where I would presumed the majority of drain-back fuel would have come from. After I powered the pump up, pressure did not come up and I noticed the ViceGrips still in place and powered it down again. I noticed the wetness from the leak when I was removing the pliers. With the pliers off, pressure came up as it should, but with fuel pouring from the pump.

I removed the pump today and have found the culprit. It’s a feature, not a bug. Pinching off the line where I did meant that the pump pushed full pressure without the benefit of the regulator to bleed off the excess. There is an over pressure relief valve on the pump and that is apparently where the fuel is leaking out.

It looks like a ball held down with a spring. I probed at it and now in operation it just seeps a little fuel, but it still leaks. I’m guessing that there is some debris in there keeping the it from fully reseating.

To get the project going while I have the time off work, I have decided to plug the over pressure valve port. I won’t be pinching off a line like that again and I will be shopping for a replacement pump because the over pressure valve really should be there, but for now I need to get this thing running!

I used brake cleaner, followed by acetone to clean and degrease the port. I mixed up some JB Qwik, the fast setting version of JB Weld and dolloped a bit in the port. I used a thin rod to stir and push the epoxy into the port and applied more, repeating until I was pretty sure there were no more bubbles in it. As I write this, it is sitting upright waiting to cure. JB Qwik is set in just a few minutes, but it says four hours to cure. It will be a loooong four hours.

One thing I will do during those hours is cranking the engine watching the coil leads to see where I need to connect the tach input. Hopefully. I may even try to run it on starter fluid enough to verify that MegaSquirt sees it spin.