TR6 1973 TR6 fuel pump

[sundown]

What is the best way to check the fuel pump pressure and what should it be?

 

[poolboy]

In the manual I have it says 1.5 to 2.5 psi
Pressure is not that important as long as it's less than 4 psi, all the pump has to do is keep enough fuel in the carbs' float chambers.
If you want to check the pressure though use a vacuum gauge. The needle swings one way for vacuum readings and swings in the opposite direction for pressure readings.


Just connect it where I have the cutoff valve. If the float chambers have gas in them, the engine will start and run for a while as you look at the gauge.

 

[Geo Hahn]

If you ever have occasion to watch the fuel coming out of a line you might be more likely to call it 'spitting' than 'pumping'. It emerges as spurts rather than a gentle stream.

The pump's job is just to keep the bowls full, hence the low pressure -- high pressure would risk overpowering the needle & seat valve that is closed by the float in a full bowl.

 

[TR3driver]

If you want to check the pressure while fuel is flowing, use a tee to connect the gauge and the carbs at the same time. Lots of problems show up as a loss of pressure at higher flow rates. I've even been known to use a hose long enough to bring the gauge out and prop it under a wiper, so I can read it while driving at high speed.

PS, the 'spurting' is because the pump only outputs fuel during every other engine revolution. The rest of the time, it is sucking fuel from the tank.

 

[Tybalt]

If you are trying to diagnose a potentially bad fuel pump, bear in mind that the fuel level in the tank will have an impact. With the fuel tank mounted as high as it is in these cars having a full tank can mask a dying fuel pump on the suction side. I've limped more than a couple of these cars home by keeping the tank relatively full and avoiding steep uphills in order to keep the fuel flowing.

You might consider doing the test with the car level and then with the front end elevated and note any differences in the results.