Triumphgt6 Posted June 9, 2023 Report Share Posted June 9, 2023 Further to my post last Monday I forot to mention that I did fit a new fuel pump , bought from a reputable supplier (No, not R.....s) in January and the engine ran in the garage without a problem while getting it tuned. Soon after it was tuned it has started to flood in the rear chamber. Fitted new floats and needle valves, no change. Even swapped over the floats, still floods. I am beginning to think it could be the fuel pump or is the tuning to fault. I can soon start that again (Although it was done by a friend who tunes Formula 1 cars). With it unable to get out of the garage safely I am missing this lovely weather. My other Triumph is a saloon. Link to comment Share on other sites More sharing options...
johny Posted June 9, 2023 Report Share Posted June 9, 2023 First before blaming anything is your fuel clean? If theres debris coming from the tank, fuel lines or hoses then the float valves can fail to seal. A filter would help once the carbs have been cleaned... Link to comment Share on other sites More sharing options...
Pete Lewis Posted June 9, 2023 Report Share Posted June 9, 2023 overpressure from the new pump has to be a good culprit they are well known for this doesnt matter where you buy from most are just a nasty copy with no respect for specifications Pete Link to comment Share on other sites More sharing options...
johny Posted June 9, 2023 Report Share Posted June 9, 2023 I wonder if its a combination of poor sealing float valves and then a new pump makes it worse. I know I had a new pump from Paddock and it was fine until a load of junk came through the system☹️ Link to comment Share on other sites More sharing options...
Wagger Posted June 10, 2023 Report Share Posted June 10, 2023 Somewhere in this section there is information on fuel pressure gauges. I have one that does pressure and vacuum. They cost about £15 to £30. Well worth the investment, or maybe borrow one. The pressure needs to be 1.5 to 2.5 psi. I removed an electric pump that provided 5 psi. That, in conjunction with all sorts of crud and slivers, caused major flooding. My old glass bowl pump provides 1.75psi. Some new ones produce over 5 psi. Then you have to muck about with changing springs. My BMC Riley amd Morris minors used an SU electric pump. In the 1970's I never had any problems with them but they do not switch off if the engine stalls. You need some complicated pressure switches and electronics (Window comparators) to make these 'Safe'. Check your float levels too but note that not all of them are easy to adjust. Link to comment Share on other sites More sharing options...
AlanT Posted June 10, 2023 Report Share Posted June 10, 2023 I had loads of drama like this. New viton valves, floats etc. 2x culprits a. Rubber slivers behind the needles from pushing fuel lines back. Take the valves out and blow through b. Floats set too high. Don’t assume it’s the pump if it was running ok for a while before the problem arose. Link to comment Share on other sites More sharing options...
Triumphgt6 Posted June 11, 2023 Author Report Share Posted June 11, 2023 After all your replies and advice, the rear carb float is still overflowing. Changed floats over, changed needles and seat. Maybe it is this newer fuel pump with too much pressure. It is supposed to be a 208493 part but has a domed roof. The old original one had a flat roof. Unable to repair as top bolt thread stripped. Before I buy yet another pump, can anyone recommend a low pressure pump for me. I do have a few other mad ideas to reduce the fuel pressure. (Good idea the car is insured for £18k) Link to comment Share on other sites More sharing options...
Pete Lewis Posted June 11, 2023 Report Share Posted June 11, 2023 domed pumps seem to be the normal crap available some just cut a bit off the pump spring or add a 3mm or so of gasket to reduce the cam travel. more have problems with the micky mouse equipment and few have found any recomendation a low psi hucco electric seem a good quality solution Pete Link to comment Share on other sites More sharing options...
johny Posted June 11, 2023 Report Share Posted June 11, 2023 48 minutes ago, Triumphgt6 said: Before I buy yet another pump, can anyone recommend a low pressure pump for me. I do have a few other mad ideas to reduce the fuel pressure. (Good idea the car is insured for £18k) Really you need a way to measure the pressure youre getting more than another pump. This pressure is set by the spring in the pump and, as Pete says, if you move the operating arm further away from the cam the spring is compressed less resulting in it applying less pressure to the diaphragm and so fuel. Using packers is what Triumph recommended in one of their workshop manuals so not a new problem.... Link to comment Share on other sites More sharing options...
Paul H Posted June 11, 2023 Report Share Posted June 11, 2023 I had similar issues so went the Huco route . Paul Link to comment Share on other sites More sharing options...
GrahamB Posted June 11, 2023 Report Share Posted June 11, 2023 I had an old fuel pump with failed valves. After removing the top half of the pump body, 4(?) screws, you can twist the diaphragm to disengage the actuating rod from the lever and gain access to the spring. I did the same with the new pump and swapped over the springs. The spring from the new pump was noticeably stronger than the original. So far the new pump with the original spring is operating without issues. 1 Link to comment Share on other sites More sharing options...
johny Posted June 11, 2023 Report Share Posted June 11, 2023 Yes designs will always vary between after market manufacturers and why Triumph indicated that adjustment may be necessary... Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now