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TR2/3/3A TR3 fuel pump

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Sumton

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57 tr3 small mouth. has about 7 miles on it. had some transmission troubles, had to remove it, get it fixed, and put it back in. that took about 3 months. fuel pump seems to have failed. no gas to carbs. put in new one, but still same problem. gas gets to the glass bowl, and if you prime the pump gas comes out. we blew out the line between the pump and the carbs and its clear.

did i perhaps not get the lever under the cam when i installed it? is there any way to test that or have i done that?

is there something else? tank is 1/2 full and as i said, gas is definitely getting to the pump. checked the cutoff valve; it is open.
 
Will it start and run briefly after you pump up the fuel pressure? If so, then I'd say there is a definite problem with the pump, perhaps installation.

But if not, you may have one or both float valves stuck closed. For some reason, our modern fuel seems to be much worse about that, especially if the car sits for a long time.
 
the car will run great if we fill the float chambers, until they empty. there is no gas delivery between the pump and the carbs.

i'm not sure what you mean "pump up the fuel pressure." if i use the primer lever, gas will come out of the pump, but never make it to the carbs. we blew the line clear so that is not the problem.

the tank is verified at 1/2 full.
 
What I mean is, can you fill the float bowls by operating the priming lever?

Also, when they are full, you should be able to feel the change in resistance at the priming lever; the pump should stop pumping when the fuel pressure reaches around 2.5 psi.
 
If the lever that actuates the fuel pump is sitting on the high part of the lobe on the cam, you cannot get any movement on the lever at the trigger end where you pull up on the lever. If you givr the engine half a turn (maybe use the hand crank), you should get some fuel to flow when you manually pull up on the lever trigger.

If someone installed the pump with the lever on the wrong side of the cam lobe you may not get any flow with the lever or with the engine running because the inner part of the lever arm may be bent (or broken) if it's on the wrong side of the cam lobe.
 
A month or so ago I ordered two new fuel pumps from Moss and found myself with a similar problem. I installed one of the pumps on my TR4A, hooked up the lines, primed the carbs with the manual lever and everything was fine. The bowls were full. I needed to idle the car a bit while I was doing other things and then it suddenly sputtered and died. I checked the bowls and they were empty so I then used the lever again and they filled up just fine. I also removed the hose at the front carb and there was plenty of gas coming out when using the manual lever. The pump appeared to be working fine. I started the car again and decided to take it around the block. Got a few hundred yards and it died again. Once again the bowls were empty.

After getting the car home, I filled the bowls again but, after doing so, removed the hose from the front carb and then started the car again. It ran fine as before, for about a minute or so, but there was no gas coming out of the hose with the engine running. It was obvious then that the cam-operated lever on the pump was not working properly, although the manual one was fine. I removed the pump and put it side by side with a known good pump. The vertical travel or lift on the new pump's lever was not sufficient to operate the diaphragm.

I tried the same pump on a TR3A with exactly the same results. The other new pump looks to be the same although I did not try it in either car. I plan to send both pumps back to Moss with a description of the problem but wonder if others have had the same issue.
 
I have had the same thing. I bought a pump to carry with me if I needed one on the road. Luckily I never did need that on on the road. But when I did need it after installing found it not working. The lever was not even touching the came. It needs about a 1/4 " to touch the came. This was one reason for installing a electric pump by the tank and carring a blocking plate if I need to remm the pump. I would have contacted who I got that pump from if I knew who and when I got it.

Don
 
Just a note in passing: After rebuilding my pump, fuel was not moving. I put a fuel pump/vacuum gage on line and saw a vacuum! The fix was to re-tighten the knob under the float bowl. I now have about 2psi. also, in the rebuild, it has the cork gasket on the diaphragm shaft and AC stamped on the check valves, 60 plus years? Le
 
2liter4cyl said:
...in the rebuild, it has the cork gasket on the diaphragm shaft and AC stamped on the check valves, 60 plus years?
Click to expand...

I have never had a check valve fail (though I have known them to fall out). When rebuilding an original pump I leave the valves in place if they appear to be operational and secure.
 
today i spent some time on this issue. a pump we received from Moss worked sometimes, but only after pumping the priming lever a few times. then it would run for a little while then die. i grabbed another pump (which i admit was marked bad on the box on my shelf) and it did not work. i then really tightened the hex head screws around the top of the pump of the one that had quit working, and which has no primer lever, and put it in. that one worked. i will be returning the one from moss. and i am now extremely good at R&R fuel pumps!
 
I have a TR4 engine and have had the same problem with the fuel pump. It works okay with the priming lever but willl not work on the car. I have purchased four pumps from differant supplier including Moss and none work. Have you figured out how to fix the problem.

Don
 
i came across a pump without the primer, and it seemed to work. at that point i decided if it weren't broke, not to fix it. i'm selling that car and i need it done and working.
i apologize for suggesting this, but it sure sounds to me like the pump is not the problem. it sounds to me like an issue with the cam. any way you can put one of those pumps in a different car?
 
DonOstmann said:
I have purchased four pumps from differant supplier including Moss and none work...
Click to expand...

Anything's possible but I would be taking a close look at the engine. I have never encountered a camshaft that has lost it's fuel pump lobe and I have never managed to get the lever below the shaft rather than riding on top of it -- but after 4 no-go pumps I would check those things.
 
I just had one one of those times when the fuel pump cam lever apparently got itself underneath the cam lobe during installation. I tried taking it off and putting it back on several times. But could not get it to work until I used a magnet to lift the cam lever while I pushed the pump into place on the two studs. It is an older pump that I have rebuilt. That may be the reason the lever is able to drop down below the cam lobe.
Charley
 
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