Fuel control system?

[dwm0121]

Have a 94 Merc. 175 XRI with no power to the fuel pump. The + side from the selenoid has 12V, the - side has no power. Turns over, have verified spark on all 6, took fuel pump off and verified it is good. Fuel control system? What else coud it be? thanks for your help. Dave

 

[Faztbullet]

Re: Fuel control system?

Fuel driver board in ECU is bad, replace the ECU with a Brucatto ACU about $500 cheaper than a Merc one.

 

[dwm0121]

Re: Fuel control system?

Thank you Faxtbullit. Not questioning your expertise, but it is a $1000 part. Should I/ can I have it tested first? I would hate for it to be a groung or something simple. I see you are in Tenn, I've been fishing Watts Bar for 30 years, love it.

 

[dwm0121]

Re: Fuel control system?

Thank you Faxtbullit. Not questioning your expertise, but it is a $1000 part. Should I/ can I have it tested first? I would hate for it to be a ground or something simple. I see you are in Tenn, I've been fishing Watts Bar for 30 years, love it.

 

[CharlieB]

Re: Fuel control system?

The fuel pump has a constant power supply, the ECU grounds the pump to operate. Disconnect the ground side wire tape it off, test that pump terminal for power, you should get a reading thru the motor, if none, verify power supply to the other pump terminal, if good supply then the pump is bad.

If you have power thru the pump, rig a temporary ground wire and attach it to the ground side of the pump, listen, does the pump run now? If no, the pump is bad.

 

[Faztbullet]

Re: Fuel control system?

took fuel pump off and verified it is good

Earllier in post.....

 

[CharlieB]

Re: Fuel control system?

Perhaps the pumps works fine on the bench with an EXTERNAL power source but it needs to be verified that there are good connections everywhere supplying the pump power once installed.

We have seen poor connections in strange places that have left many of us scratching our head until we started over and rechecked.

But you're right, I should have pointed out that if the pump does NOT run with a ground wire attached, to verify power supply before condemning the pump.