Ok. To make a long story short, my old fuel pump began to spew oil & gas all over my freind's parents driveway, so I replaced it.

Now when the engine is cold I hear thumps from the engine that speeds up when the rpm's increase(slows down as rpm's decrease). When I installed the new pump, I didn't lubricate the pump arm. The fuel pumps operates fine. But, could this be causing the problem.

I thought it was a bottom end problem, but maybe it's the new pump. Also, I have never heard this noise until I replaced the pump.

I changed the oil a week after replacing the pump, with Synthetic Mobil-1 15/50 + a Powerpunch additive. My engine is a 1978 350. The puel pump has a short arm.

Maybe someone can help me :hail:

 

anyone?

 

Joe,

There's usually no need to lubricate the pump arm for normal replacement, although a little dollop of grease on the end of the pump shaft never hurts when assembling a new engine. The pump shaft is pretty well-oiled, and the pump pivot and arm itself get plenty of oil, as your failed unit revealed. You may have a faulty replacement pump, or may have the push rod out of position somehow, although if the pump is operating, it can't be that far off. It's also possible that the new pump has a different lever and/or spring that doesn't return the pump push rod fully.

 

I think it's a floating pushrod. The pump may be a defect or the rod could be out of position. Hard to do because theres not much clearance, but it could happen I suppose.

 

The noise occurs randomly, so I don't hear it all the time. I also have bad lifters, maybe that has something to do with it . I was thinking about rebuilding the top end, but I will be trying to sell the car soon. I'm hoping on getting at least $1000 for it. Here's its best picture: