Results 1 to 17 of 17

Thread: TR3 fuel pump

Discussions of Triumph motor cars

  1. #1
    Senior Member
    Join Date
    Jun 2015
    Location
    dallas, tx
    Posts
    79
    Thanks Thanks Given 
    0
    Thanks Thanks Received 
    0
    Thanked in
    0 Posts

    TR3 fuel pump

    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.

  2. #2
    Great Pumpkin TR3driver's Avatar
    Join Date
    Aug 2003
    Location
    Sunny So California
    Posts
    18,989
    Thanks Thanks Given 
    4
    Thanks Thanks Received 
    72
    Thanked in
    69 Posts

    Re: TR3 fuel pump

    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.
    Randall
    56 TR3 TS13571L once and future daily driver
    71 Stag LE1473L waiting engine rebuild
    71-72-73 Stag LE2013LBW waiting OD gearbox rebuild

  3. #3
    Senior Member
    Join Date
    Jun 2015
    Location
    dallas, tx
    Posts
    79
    Thanks Thanks Given 
    0
    Thanks Thanks Received 
    0
    Thanked in
    0 Posts

    Re: TR3 fuel pump

    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.

  4. #4
    Great Pumpkin TR3driver's Avatar
    Join Date
    Aug 2003
    Location
    Sunny So California
    Posts
    18,989
    Thanks Thanks Given 
    4
    Thanks Thanks Received 
    72
    Thanked in
    69 Posts

    Re: TR3 fuel pump

    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.
    Randall
    56 TR3 TS13571L once and future daily driver
    71 Stag LE1473L waiting engine rebuild
    71-72-73 Stag LE2013LBW waiting OD gearbox rebuild

  5. #5
    Senior Member
    Join Date
    Jun 2015
    Location
    dallas, tx
    Posts
    79
    Thanks Thanks Given 
    0
    Thanks Thanks Received 
    0
    Thanked in
    0 Posts

    Re: TR3 fuel pump

    no gas comes out of the fuel line at the carbs when operating the priming lever

  6. #6
    Darth Vader Don Elliott's Avatar
    Join Date
    Dec 2004
    Location
    Montreal, Canada
    Posts
    2,690
    Thanks Thanks Given 
    0
    Thanks Thanks Received 
    0
    Thanked in
    0 Posts

    Re: TR3 fuel pump

    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.

  7. #7
    Freshman Member
    Join Date
    Sep 2010
    Location
    Houston, TX
    Posts
    3
    Thanks Thanks Given 
    0
    Thanks Thanks Received 
    0
    Thanked in
    0 Posts

    Re: TR3 fuel pump

    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.

  8. #8
    Jedi Warrior donbmw's Avatar
    Join Date
    May 2002
    Location
    Monroe LA
    Posts
    479
    Thanks Thanks Given 
    0
    Thanks Thanks Received 
    0
    Thanked in
    0 Posts

    Re: TR3 fuel pump

    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
    Don
    1959TR3A,2006 Soltice
    1975R90/6,1980R65 & 1982R65 BMW motorcycles

  9. #9
    Senior Member
    Join Date
    Nov 2014
    Location
    Biggsville,IL
    Posts
    81
    Blog Entries
    1
    Thanks Thanks Given 
    3
    Thanks Thanks Received 
    0
    Thanked in
    0 Posts

    Re: TR3 fuel pump

    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

  10. #10
    Yoda Geo Hahn's Avatar
    Join Date
    Sep 2001
    Location
    Mt Lemmon, Arizona
    Posts
    9,324
    Thanks Thanks Given 
    0
    Thanks Thanks Received 
    8
    Thanked in
    8 Posts

    Re: TR3 fuel pump

    Quote Originally Posted by 2liter4cyl View Post
    ...in the rebuild, it has the cork gasket on the diaphragm shaft and AC stamped on the check valves, 60 plus years?
    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.

  11. #11
    Senior Member
    Join Date
    Jun 2015
    Location
    dallas, tx
    Posts
    79
    Thanks Thanks Given 
    0
    Thanks Thanks Received 
    0
    Thanked in
    0 Posts

    Re: TR3 fuel pump

    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!

  12. #12
    Freshman Member
    Join Date
    Mar 2009
    Location
    Missouri
    Posts
    9
    Thanks Thanks Given 
    0
    Thanks Thanks Received 
    0
    Thanked in
    0 Posts

    Re: TR3 fuel pump

    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

  13. #13
    Senior Member
    Join Date
    Jun 2015
    Location
    dallas, tx
    Posts
    79
    Thanks Thanks Given 
    0
    Thanks Thanks Received 
    0
    Thanked in
    0 Posts

    Re: TR3 fuel pump

    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?

  14. #14
    Yoda Geo Hahn's Avatar
    Join Date
    Sep 2001
    Location
    Mt Lemmon, Arizona
    Posts
    9,324
    Thanks Thanks Given 
    0
    Thanks Thanks Received 
    8
    Thanked in
    8 Posts

    Re: TR3 fuel pump

    Quote Originally Posted by DonOstmann View Post
    I have purchased four pumps from differant supplier including Moss and none work...
    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.

  15. #15
    Jedi Knight
    Join Date
    Apr 2013
    Location
    redding,ca
    Posts
    969
    Thanks Thanks Given 
    1
    Thanks Thanks Received 
    2
    Thanked in
    2 Posts

    Re: TR3 fuel pump

    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

  16. #16
    Yoda Geo Hahn's Avatar
    Join Date
    Sep 2001
    Location
    Mt Lemmon, Arizona
    Posts
    9,324
    Thanks Thanks Given 
    0
    Thanks Thanks Received 
    8
    Thanked in
    8 Posts

    Re: TR3 fuel pump

    Just re-read the original post and saw this:

    Quote Originally Posted by Sumton View Post
    ...did i perhaps not get the lever under the cam when i installed it?...
    Just to be double-darn sure you know this -- the lever goes on top of the cam.

  17. #17
    Senior Member
    Join Date
    Jun 2015
    Location
    dallas, tx
    Posts
    79
    Thanks Thanks Given 
    0
    Thanks Thanks Received 
    0
    Thanked in
    0 Posts

    Re: TR3 fuel pump

    thank you. yes, i mistyped. but that car is running, that problem is solved . . .

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •