• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

TR4/4A Fuel pump won't pump

Share this page

doughairfield

doughairfield

Jedi Trainee
Offline
Hi,
I have the standard mechanical fuel pump from Moss Motors with the priming handle and it seems to have stopped working, yet I can't find the cause. I can get 1 good pump from the priming handle but after that, I basically get no suction on the fuel tank side and no fuel coming out the exit side of the fuel pump. If I wait a minute I can get another good pump with some fuel moved but after that nothing. It's like the diaphragm and rod are getting stuck in one position.. I've taken the fuel pump apart and everything appears to be in working order. The diaphragm appears to be ok and I don't believe there is anything clogged internally.

Any suggestions on where to look next?

!964 Triumph TR4
Doug Hairfield
 
Did you try pumping the fuel pump by hand off of the engine? That is you would need to hook up a line on the intake side going into the pump and see if you can pump any fuel out of a container. What I am shooting at here is that it could be a blockage in your fuel line or fuel tank outlet. My son had this problem when somebody dumped a toy in his TR3 tank and one of the stickers on the toy came loose and partially plugged the tank outlet. He thought it was the fuel pump as well, but a new pump did not correct the problem. Besides a plug in the fuel line you could also have a restricted line caused by something that has crushed your fuel line.
I use a locking gas cap on my TR4's!
Charley
 
I was thinking that there could be a clog in the fuel line so I filled a small bottle with gas and with the fuel pump removed, I put the intake end in the bottle. Same deal, I could get one good pump but after that nothing. Fuel also seems to be flowing freely from the fuel line come from the gas tank when it's disconnected from the fuel pump.
 
Then the best fix is a new fuel pump. Or rebuild an old one-- not suggested on the newer pumps. Sometimes we just don't know why the darned things don't work. But the evidence is that they do not. Best to just move on. But you might not want to get another of the same source that you just had. You might contact Moss, maybe they will send you a new one if your was not to old.
Charley
 
Thanks for the advice, I'm going to go for one from BP NorthWest this time, they were a bit cheaper that Moss.

I have heard from some of the guys in my club around here that the mechanical fuel pumps are hit or miss on reliability. Hopefully I'll have the new one here by the weekend and I can change it out.

Thanks again.
 
I think the lack of reliability on mechanical fuel pumps refers to the aftermarket replicas being
sold these days. My advice is try to find an original AC pump, rebuild it or have it rebuilt, install it
and keep the aftermarket one as a spare. Email this guy in Mass., The Cellar @ then-now.com
He is an expert on AC fuel pumps. He can tell you the AC part number(s) for a pump for
your year TR4. Armed with that information, find one for rebuild. The Cellar @ then-now.com
also sells the correct rebuild kit once you source the pump itself. He rebuilt my original 22 years ago.
Still going strong.
FRank
 
Last edited:
Back
Top