Mercrusier 5.7 no power to injectors!

[toddsallee]

I have spark, fuel pump working but no power to the fuel injectors. Any thoughts much appreciated! Injector fuse looks good!

 

[alldodge]

Which Merc 5.7?
Have a serial number?

 

[Bt Doctur]

MPI or throttle body type

 

[toddsallee]

MPI or throttle body type

Throttle body

 

[toddsallee]

Which Merc 5.7?
Have a serial number?

EFI

 

[alldodge]

12V is not present on the pink wire with ignition turned ON. Check fuses under cap (seen next to item 16)

 

[toddsallee]

They all look good. Any other thoughts? Thank you for your time and effort!

 

[alldodge]

12V is not present on the pink wire

Is there 12V on the pink wire connected to each injector?

 

[toddsallee]

Thanks! I check it in the next hour or two!

 

[Bt Doctur]

click to enlarge

Using a different manual injector power and ground com from the ecm#21 is the main power feed, you need 12 here to start.Then at relay 14 you need 12 v. Fuse 16 is critical

 

[toddsallee]

Pretty much no voltage read!

Is there 12V on the pink wire connected to each injector?

No, I did see there is 12v on the fuel pump. So I ran a jump to the injector and it sprayed fuel!

 

[toddsallee]

Pretty much no voltage read!

click to enlarge

Using a different manual injector power and ground com from the ecm#21 is the main power feed, you need 12 here to start.Then at relay 14 you need 12 v. Fuse 16 is critica

Thanks I starting right now to check power at the ecm#21

 

[toddsallee]

Pretty much no voltage read!

Thanks I starting right now to check power at the ecm#21

click to enlarge

Using a different manual injector power and ground com from the ecm#21 is the main power feed, you need 12 here to start.Then at relay 14 you need 12 v. Fuse 16 is critical

n

 

[toddsallee]

No Power at the ecm#21. Guess I need to replace that breaker. Question could that breaker be bad and still I have spark and power to the fuel Pump>

 

[alldodge]

Pretty much no voltage read!

No, I did see there is 12v on the fuel pump. So I ran a jump to the injector and it sprayed fuel!

The fuel pump has nothing to do with the injectors. I wanted to know if there was 12V when the key is turned ON, with one of the wires on the injectors. One of them (pink or red) will have 12V when ever key is ON.

Th other side of the injector goes to the ECM and the ECM applies a ground to turn it ON

No Power at the ecm#21. Guess I need to replace that breaker.

Its NOT the 50 amp breaker.
If you do not have 12V at the injector then go to the fuse.
Check for 12V at each fuse.
If 12V is on both sides of the fuse, then check the relay

 

[toddsallee]

Yes there is 12v on one side of the injector.
But the ground back to the ECM does not appear to be good! What does that mean. Thanks again!

 

[alldodge]

Yes there is 12v on one side of the injector.
But the ground back to the ECM does not appear to be good! What does that mean. Thanks again!

ok then the ECM is not turning the injectors ON

When cranking do you see the tach show at least 300 rpm or maybe it doesn't move at all

See if you can find the serial number. Look above the starter for a plate on the block. What year?


If no plate, which ECM do you have

 

[alldodge]

Is this a new to you boat, or did this problem just started?

 

[toddsallee]

ok then the ECM is not turning the injectors ON

When cranking do you see the tach show at least 300 rpm or maybe it doesn't move at all

See if you can find the serial number. Look above the starter for a plate on the block. What year?


If no plate, which ECM do you have

F349479 serial Number Tach does goes up to at least 300 rpm

 

[toddsallee]

Is this a new to you boat, or did this problem just started?

Had the boat for 3 years. Run it alot! I live on a lake. Just started last week! Thanks again!