how to test fuel pump?

[keasling]

how would you test a mechanical fuel pump for a 97 ford diesel 7.3? we think it went bad and want to find out before we drop the money into a new one. thanks

[pipelayerjdh]

Put a fuel pressure gauge on the schrader valve on the side of the fuel bowl and crank the engine. I think minimum pressure is 40-50psi.

[gbear]

My shop manual says 40 psi on a 95, I don't have a manual on the 97 but they are most likely the same.

Jim

[keasling]

we have no fuel pressure on the schrader valve on the side of the housing but on the low pressure on the fuel line side any ideas what we need to do?

[keasling]

before all this we kept losing pwoer it just had no get up and go. I posted the problembefore in my other post. just trying to figure all this out. Now the truck wont start it will turn over though.

[Jeff_Northon]

Look for an air leak between the tank and the schrader valve. Pump may be good, just sucking air, so no fuel pressure.

[nu2diesels]

i also seem to be having the same problem. my truck gives me a hard time when i try to start it after a few days of non-use and when i try to drive it, at times it will loose all power yet wont shut off. i'm not trying to highjack your thread by the way, just sharing similar experiences. good luck cause i know i'll need some.

[ronhauser]

have you checked your hpop for good pressure? Sounds like low fuel pressure or low oil pressure. I justed replaced my hpop due to low pressure, should max out around 3000 psi under load. Fuel pressure should idealy be around 55 to 70 psi.

[ronhauser]

Also need to check fuel volume and not just pressure.

[coaltrain444]

This sounds dumb but how much fuel is in the tank?