Logo
FULL SITE MENU

Fuel pressure for 94 OMC 58 l cobra EFI

  • Thread starter David Burington
  • Start date
D

David Burington

Guest
I just bought a used boat with

I just bought a used boat with a 94 omc cobra 5.8 liter FI engine. My low pressure pump was working but my high pressure pump was dead. I replaced it and the motor still doesn't run unless I squirt gas in the intake. It will run for a few seconds until the gas is gone. I have 40 psi of pressure at the rail and not sure what it supposed to be. Any help will be greatly appreciated.
 
40 psi should be enough. Is th

40 psi should be enough. Is the relay working?
It's been awhile but I do not recall this system having two pumps and see no reason why it would.

I guess you need to find out if the pump is running when the ignition is turned on. The pump should run for a second or two when you first turn on the key just as a vehicle with efi does.

Then after the engine starts depending on the system either the distributor sends a signal to the relay to start the pump or a signal is sent by the oil pressure sending unit. Could be both.

If you loose oil pressure the pump should shut down so the engine is not damaged or enter limp mode.

As I said I'm not sure of this two pump system and see no reason for it but that doesn't mean it is not there.

If you have 40 psi on the rail the engine should run. Check the pressure while cranking the engine and see if it drops.
If it does the relay may not be turning on the pump for some reason.

You can bypass the relay for testing the pump but do not run the engine for longer than needed to tell if this is the problem.

Also check the temp sender for a false reading leaving the circuit open.

There could be many reasons the system is not working these are just a few of them.

Could be the regulator etc.

Hope you find it.
 
"i have a 1996 ford 5.0l efi a

"i have a 1996 ford 5.0l efi and have the same problem only i thought it was the low presser pump, just replaced it and still have the problem/i've noticed that the engine seems to heat up so i replaced the water pump guess now i need to change the thermosat too ...."
 
Back
Top