Then go up to the engine comp fuse block. Black meter lead to battery negative, red meter lead to the fuel pump priming tab, metr on 20vdc scale, measure during prime cycle.

These last three tests should give us everything we need to know to determine your problem.

George



George

 

did the tests as you asked in this order.

test: pump connector disconnected testing grey wire. Positive lead to pump connector negative lead to shiny frame.

Results 11.8v during priming

Same exact test except with pump connected and red lead back probed in.

results -9.2 mili vdc???

last test. Batt neg to fuel priming tab during priming.

Results 11.8.

 

What this tells us is that you probably have a wiring problem between the relay and the pump connector because you have complete voltage drop in that wire under a load. Pull the fuel pump relay and fuel pump connector and measure the resistance between the connector gray wire and the fuel pump priming tab. It’s probably going to be very high.

George

 

tested and i have 8.3kohms. What do you suggest? Run a whole new wire or can you tell me which loom is the one that runs from the relay box to pump?

 

Bingo!

You can either trace the wire loom and look for the problem or run a whole new wire. To check before all that work you can run a 16 or 18 gauge temp wire from the priming connector to the pump gray wire at the pump and see if it primes/starts. Your ground wire resistance is also too high so we may need to run a temp ground wire to your shiny frame spot to get this thing started.


George

 

Trace the loom backwards from the pump if your going that route.


George

 

Hey George, just wanted to say thank you so much for the help. It was in fact the power wire. I ran a temp to confirm and she started right up! Appreciate all the help.

 

Congratulations, you just performed a proper diagnosis and targeted repair. Always check the wiring and voltage/signal levels before replacing parts and don’t forget to confirm the repair and see what normal voltages look like.

George