M20 b25 fuel pressure

[RossDavies]

Hey all,
When I put a fuel guage inline I get 2.5 bar. I only get 3 bar when I remove the vacuum line from the pressure regulator. Is this normal?

[paultv]

Correct, you have to take into account the vacuum in the inlet...so 2.5 bar is correct between fuel and atmosphere....which is outside the engine...whilst fuel to inlet manifold pressure is 3bar but that's not what you are measuring. Removing the vacuum line does the job of allowing the lnlet to become atmospheric pressure which then shows 3 bar. So your engine is fine!

Paul

[RossDavies]

Thanks!