Quote Originally Posted by miked50 View Post
got the same situation too (we have the same motor)...priming pump does not get hard even after numerous pumps. yet it pumps fuel. when i replaced the priming pump, it will get hard after about 5 pumps on it. the return line (after the injectors) is plumbed back to the IP via a banjo bolt on the rear of the IP then goes back to the tank. previously i had a loose clamp holding the return line and the engine would cut me off on WOTs.

hth
I've also been thinking the head gasket...but I have no hard evidence other than a hunch. I was hoping to find leakage between two cylinders (i never checked this while I was doing the test, i'll kick myself for being a noobie). the leakage test I performed is pointing towards the rings if anything.

I will have to recheck my return lines..i know its not in the greatest of shape.

the fuel primer pump: I know people have replaced them because the o-ring sealing face was rusted and letting air in the lines, or there was a crack around the inlet/outlet and letting air in, I don't see those problems with mine (and no air in the lines after the primer pump...)