[LuckyBoy]

I am days away from being able to drive my baby again after 5 long years since I purchased it. I am running into problems with the fuel pump. This is the original pump off of the 255 that came with the engine when it was running. (original was stolen due to an engine shop going bankrupt) I bought the appropriate size fuel pump rod, made sure that the fuel pump was pressurized and free moving, installed, but when the engine turns over I get no fuel.
I was told by my friend, its in his garage, that he took the fuel pump off and turned the engine over to see if the rod was moving, he said no.....is there any special installation notes for the rod that I am unaware of? I assumed you put it into the receiving hole in the block, pushed the pump down on top of it and the pressure held it in place.
Any help would be amazing.

[oldracer]

First, check the fuelpump pushrod for wear on the bottom where it contacts the cam. If it doesn't show wear, probably the eccentric on the cam is worn
out. I've seen this many times before. You have an option of replacing the cam or using an electric fuel pump. If you use an electric fuel pump, be sure
to use a fuel pressure regulator set to about 1 1/2 lbs pressure. Flathead
carburetors don't tolerate too much fuel pressure, particular Strombergs.

oldracer

[LuckyBoy]

The engine is a fresh rebuild from Precision Engineering in Texas so I would hope it wouldn't be the cam. The fuel pump rod was still in the packaging when I got it.

[techinspector1]

We used to shim the pump rod with the tongue out of an old leather shoe. Cut a piece to fit, shim it and see what happens.

[LuckyBoy]

Shim the pump rod even though it is apparently not moving with the engine turning over?

[cobalt327]

Originally Posted by LuckyBoy

Shim the pump rod even though it is apparently not moving with the engine turning over?

It would be odd for the pump eccentric to be totally gone. If the push rod is against the cam, it should show SOME movement- even if it's inadequate.

I'm wondering if the rod is the right length and may not even be touching anything...

There are three different p-rod lengths available for flatties:

7-7/8", 8-7/8" and 10-1/16". You may not have the correct one.

In case you need it, there's a diagram for the FUEL PUMP.

[LuckyBoy]

I have the right length as when I placed it into the cam, and then went to attach the fuel pump i had to compress the pump just to get it attached, my question I guess would be why wouldn't the pump rod be moving?

[alittle1]

Originally Posted by LuckyBoy

I have the right length as when I placed it into the cam, and then went to attach the fuel pump i had to compress the pump just to get it attached, my question I guess would be why wouldn't the pump rod be moving?

1. The rod has slipped off the pump fulcrum.

2. The rod's too short.

3. The cam is worn.

4. The pump is worn and the pushrod is not activating the pump diaphram.

Try pulling the pump out, hold your finger on the tip of the pushrod and have someone bump over the engine. Feel for lift on the push rod. If there is lift on the pushrod, go to the pump and work the fulcrum back and forth and measure pump pressure with a vaccum guage. If there is pressure, try priming the pump with fuel and re-install, making sure that the fuel pickup has fuel. ( Clear plastic tubing in a gas can will tell you real quick if it is sucking. ) and a clear plastic tubing after the pump will tell you if it is pushing the fuel to the carb.

Sometimes its just the little things that cause the biggest problems.

ALSO: Even though you had to compress the rod to put the pump on, it doesn't mean that the rod isn't OVER COMPRESSED and that is the reason it is not pumping fuel. Try putting two or three gaskets on to get the correct pumping action and subsequent pressure ( read fuel) to your carb.

[bigdog7373]

Or you could just not worry about it and use an electric pump. I had a similar problem, my pump wouldn't prime and when it did it would lose prime as soon as you shut the engine off. I bought a mr gasket electric pump from autozone, hooked it up, bypassed the mech pump but left it in place, and now i don't have any problems. Cost me 20 bucks. You will need a pressure regulator though.

[LuckyBoy]

I appreciate the feedback, and I should be able to tinker around with it again on Saturday morning. I will try to get the original working, and if all else fails, Autozone is around the corner anyways.
Thanks for all the help and I will let you guys know if/when its running. (Might take a week to let you know as I will be giddy as all hell driving it everywhere!)

[LuckyBoy]

Bought the Mr. Gasket fuel pump, not quite sure what regulator to go with, my buddy is saying he ran it without a pressure regulator and it has been working fine. I should be aiming for 4Lbs right? Also I could not find one for 6V application, only 12 V, I am assuming I can probably get it to work on 6V regardless, is this what you did?

[LuckyBoy]

Thanks to all who helped! And just so that anyone who had the same problem that reads this, I used a Mr. Gasket 40 dollar fuel pump that says it is rated 12V and works just fine on 6. Used a toggle switch as it likes to flood the engine at start...but she purrs now!
Thank you to all who replied, I feel like I just had a kid or something!