Nagrom22

95/f150 /5.0 (running lean on right side is original problem)
just did pressure test.20 psi engine on,35-37 psi at idle.
New pump? If so whole unit or just pump?
Also, replaced fuel filter week before test
Let me know what you think
Thanks

16IngotFX4

What about the pressure regulator?

Steve83

I think: not enough info (too short sentences) more details needed.

raski

Are you having a problem? Specs call for 30-45 psi at idle.You can go one step further, pull the vacuum line off the regulator and start the engine. Pressure should go up and be fairly steady when you work the throttle. If you have a brief large drop in pressure before the pressure builds back up, the pump is weak. Do not change the regulator unless raw fuel comes out of the vacuum port of the regulator.I don't think that is the case as the engine would be running poorly and extremely rich.

fomoco998

Just happened to me in the past two weeks problem lean condition . My 95 5.0 only has one o2 sensor so lean condition is not related to a side of engine . Your fuel pressure should jump up with vacuum hose disconnected or when you wide open throttle . I have two different gauges and they read different . After all the testing I did I had to clean MAF and all is well . No code for MAF but to clean it I had to remove the plate protecting the elements to clean it properly .Codes and tests are important before throwing parts at it ..

Nagrom22

Thank you for your info on checking the pressure regulator,
just found small air leak in vac line to regulator, maybe the problem?what do you think?
Will replace and let you know if check light goes out
Thanks again

fomoco998

A vacuum leak will cause lean condition and check engine light from o2 sensor .