[TR] Fuel pump gone wild

[DAVID MASSEY]

 Dunno.  What model fuel pump is it?  Is it one of those pulsing models?  Those I think just use the spring to determine the pressure.  The only thing that could cause those to over pressure would be a piece of debris caught in the spring.
A rotary style most likely has a pressure relief valve.  If the valve gets clogged the pressure will be uncontrolled.
 
Dave 

 
 
-----Original Message-----
From: Bud Rolofson <levilevi at comcast.net>
To: Triumphs <triumphs at autox.team.net>
Sent: Fri, Feb 25, 2022 1:15 pm
Subject: [TR] Fuel pump gone wild


Listerati,

What could happen to make my Spitfire mechanical fuel pump start pumping excessive fuel pressure? I tried two different vacuum gages inline to the fuel line between the pump and the carbs and they both showed over 10 psi (maxed the gage actually). That overwhelms the float needle valves and makes the carbs flood making the engine barely idle and die if I try to increase the rpm’s.

I guess I don’t know enough about how fuel pumps limit fuel pressure internally. Is there something internal to the pump that could fail? Maybe one of the round valves?

I also tried inline fuel pressure regulators (three different ones) but it didn’t seem to faze the high pressure. That was puzzling also.

Once it warms up a little I’ll try a spare pump.

Thanks
Bud


Sent from my Commodore 64 Sent from my Commodore 64
** triumphs at autox.team.net **

Donate: http://www.team.net/donate.html
Archive: http://www.team.net/pipermail/triumphs  http://www.team.net/archive

Unsubscribe/Manage: http://autox.team.net/mailman/options/triumphs/dave1massey@cs.com
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://autox.team.net/pipermail/triumphs/attachments/20220225/1deda871/attachment.htm>