Fuel Pump Blues

If all else looks good, I bet one of the check valves inside the pump has fallen out of its place.
Needs to be staked in tightly, had this happen on mine a few years ago.
New pump, ran for a day, then just quit pumping fuel.
Took it apart and it was laying in the bottom cavity.

 

Pulled the pump and it passes the “one way blow” test. When I disconnected the ‘out’ line, fuel came out. So, it seems like it’s trying. I reinstalled it without the spacer. I didn’t have time to test it this evening. Hopefully tomorrow.

 

Well . Still no good!

If a check valve fell out, would the air still be restricted when blowing through it the wrong wayKnowing myself, this is some small, stupid thing that I’m not seeing.

Not giving up here, but getting frustrated. I’m a donkey on the edge!

 

Yes. Both valves prevent reverse flow.

When you test by having it mounted, and cranking the engine, is the pump's output line disconnected from the carb? In other words - are you sure the carb float valve is not stuck shut?

 

I’ve been running the line disconnected from the carb, disconnected at the carb. I put a cup to catch anything. There is fuel getting to the line to carb, just not pumping any quantity out.

Am I not wrong in assuming it should be delivering a measurable quantity of fuel out the top of the fuel line at carb (disconnected) when cranking and running with starting fluid?

 

Well, I guess I’ll open the new one up and see if there’s anything obvious. Worst case scenario, I buy another.

I can’t stop thinking that there’s gotta be something I’m missing. The original worked “when parked”. I get a new one and it doesn’t work. I’ll figure it out.

 

Yes. Literally 'measurable' and the FSM specifies how much.

It also specifies (separately) the output static pressure the pump should demonstrate.

If you don't have an FSM, you should.

 

It’s in my cart, haven’t checked out yet. I’ve got a Haines,…I know it’s not the same. I did download the FSM, but I’m old school. I like a hard copy.

Regardless, I don’t need the FSM no measurable fuel is bad.

Another FP is on the way.

 

I feel your pain, been there and at times still doing it.

 

This sounds similar to a problem we had trying to start my dad’s mustang after 20 years of sitting. No fuel flowing into the carb when cranking the engine.

To isolate the pump, I pulled the fuel hose off the carb, and pulled the fuel inlet hose off the pump. Then I ran a hose from the pump inlet and into a full Jerry can sitting next to the car. Cranked the engine and within a few seconds we had a solid flow of fuel coming out the carb line. So then I hooked everything back up correctly, cranked it again, and it fired right up. Still not sure what the problem was. I assume there was some sort of vapor lock that we needed to overcome by bypassing the lower fuel hoses.

 

I’ve got virtually the same system hooked up to the Jeep now. Still fuel pump flatline.

 

Take it apart and check the valves inside. While you're in there check the diaphragm.
What've you got to lose except $$ on another pump?
Thats the same one I had the issue with I mentioned earlier.
Took 10 min to fix, been running for 3 years since.

 

Sure, I’ll check it out. I’m dying to play with it, but I’ve got a busy week ahead. I’ll get back after I’ve had time to take the big hammer to it.

 

It’s been a few weeks since I’ve had opportunity to work on this problem, but I’m happy to report, the problem is SOLVED!

I did three things differently, and one or all worked.

1. I was listening to Turnpike Troubadours instead of R. L. Burnside.
2. I as smoking Lane 1-Q instead of half and half.
3. I used the glass bowl type pump instead of the flat kind.

The failed fuel pump was the flat kind, so that’s what I initially replaced it with. I couldn’t get that replacement to work. I almost went electric, but I thought I’d try glass bowl style first. When I received it, I could tell it was different. Working the lever, it seemed much ‘suckier’. I slapped that puppy on, and the combo of the right music, tobacco, and fuel pump started spitting out fuel after a few cranks. Hallelujah!

 

Glad you got it solved.
Now, with all the free time you have now that your rig is running,
take your old pump (and the replacement) apart and see why they failed.....

 

Before I bought the latest one (glass bowl), I pulled apart the other new one. I couldn’t find anything wrong with it. It’s a good idea to pull apart the original. I also felt inside for the cam that the arm rides on. It was perfectly smooth, no scoring or sign of wear.