ochinchillas

i got a 89 jeep cherokee and the engine cranks and turns but the fuel pump wont get no power to it, if i by pass the relay the pump starts but the engine still keeps crnking an turning but won't start, what else could it be?

tjwalker

Need to determine if you are missing fuel or spark.

If the fuel pump runs and the engine doesn't start, you should check for fuel pressure at the schrader valve on the fuel rail. Be careful. Best to do it with a gauge and you will need approximately 31 psi to start your 89. If your fuel pump runs and you don't have fuel pressure, your fuel filter is clogged or your fuel pump is toast.

If you have good fuel pressure, verify that you have a strong, blue, snapping spark which is necessary for the engine to fire up.

cruiser54

Got a test meter? Gonna need it to go any further unless you wanna just throw parts at your Jeep.