1955 12 Valve NAPCO Clone

[Luther Grimace]

So I have been thinking about my problem for the past couple of weeks in a state of depression about having to take my pump to a professional, hat in hand ,admitting defeat that I couldn't fix it with common tools. On Friday after work I was CLR'ing the rest of the cab and started thinking about the fuel level in the tank corresponding with the holes on my sending unit that I drilled to act as my return. I had test the fuel pressure earlier in the week and I was getting 3-5 psi after the filter which was in specs.

So with that thought in my head I grabbed (2) 5 gallon gas cans and jumped in my trusty 65 Chevelle and drove to the store. I filled them both up with diesel with my plan being to fill the fuel tank to the brim to elimante any air being sucked into the system.

When I got home, I dumped both jugs in the truck and it didn't overflow it. So I took one jug and ran back up to the store and filled it up. It didn't take much of the second jug to overfill it.

I then took and started the truck. It still had a miss but it was running much better and had a fuel haze. I found the dead miss to be on the #2 cylinder so I am gonna swap the injector with #3 to see if the miss follows the injector. I have my fingers crossed that it will. If it does I am going to get some 5 x .012 hole injectors on the way and replace them all.

I also purchased a new pickup tube to eliminate any air getting into the return side. I think the main problem comes from the bottom of the tank supply outlet. I had checked the fuel flow by removing the hose and I had good flow. I think that when the lift pump pulled a vacuum on it that it was causing a whirlpool effect on the fuel causing me to get air and fuel into the pump. If the truck continues to act up I am going to purchase a bulkhead to add to the top and use the original pickup tube for my supply like my Canadian friend 6BT 56.

I hope this was the problem all along but the fact that my timer piston in my injection pump was locked up still makes me happy that I addressed the pump. I will update as soon as I get some more news.

Also as a side note I started on the wiring and hope to get it finished and installed as soon as I get my new headlight switch. I'm catching a second breath hopefully.