Injectors not firing, 2020 DF90

[defrag4]

Hey guys, I am helping a friend with his boat, he said he was out on the water and it died, and he has not been able to get it to start since.

I went over yesterday and checked it out, motor is basically brand new, only 200hrs on it. I hooked up SDS and scanned for codes and there are none.

I blasted some carb cleaner in the intake and she popped right off and would run as long as I kept her fed with carb clean, so we know we have spark.

I started chasing the fuel all the way to the rail and found we have fuel to the rail so we know our pumps are good

I pulled off the injector rail and had him crank over the motor, nothing came out of the injectors.. ok well theres our problem...

I backprobed the injectors and all have 12.5v at the connector, if I run the SDS test I can hear the injectors click, if I ground the injector manually to the engine I can also get them to click and spray.

So for whatever reason, the ECU is not sending the injector pulse signal to the injectors.

I dug around and checked everything I could see with a visual inspection and all looked fine, no pulled or chafed wiring seen.



So I am thinking there must be some safety cutoff or something that is preventing the ECU from sending the signal? Or perhaps the ECU itself is cooked?


Any ideas what else would prevent the injectors from firing but still allow the engine to have spark? I see talk of the CMP/CPK sensors but they are throwing no codes and she seems to have good spark, so I imagine they are ok?

Here are the readings from SDS


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RuY8KKL.png

[defrag4]

OK, got a noid light and determine the injectors are getting signal, pulled the rail out again and cranked for a bit longer and confirmed the injectors are actually firing as well...

so what the heck, i got spark, i got fuel... must be missing air?

maybe the IAC?

kind of strange that it will still run off of carb cleaner but not the fuel injectors

[Freddy jakob]

Have you tried starting it with a little throttle?
If it does, it's likely an iac problem

[defrag4]

I tried giving it a little bit, Ill try giving it some more next time I am over there, I think you might be right since it will fire off with carb cleaner, which is basically just a super enriched mix

[artdf175]

I'm not sure of one thing on your SDS reading
Emergency stop switch - off???
Is the emergency cut off clip still in place where the on/off key is on the remote??
Art

[defrag4]

I'm not sure of one thing on your SDS reading
Emergency stop switch - off???
Is the emergency cut off clip still in place where the on/off key is on the remote??
Art

ya i pulled it and it switched to ON, so I guess thats just how it reads the signal, when I pulled it the starter doesnt even attempt to turn over, so it appears to be working normally

[artdf175]

ok--
you mentioned there is fuel to the rail..
is the fuel rail pressurized?
when to initially turn the key on there is several seconds when the high pressure fuel pump in the VST pressurizes the fuel rail.
Can you tell if that is happening?

[artdf175]

It would not be the IAC valve as that controls unstable idle or stalling
however, would check the Netural Switch.
"when the shift is in forward or reverse at the time of engine start, the fuel injection function is cancelled"

which more or less describes what you are experiencing

[defrag4]

jesus christ... you guys wont believe this one

so I get back over there today, pull the flywheel off to inspect the IAC, all looks good, I swap it with my spare IAC, put it all back together, same problem

try all kinds of tricks and can just barely get it to run before dying

Just about to give up when I pull off the fuel line and dump it into a jar again, no water in the gas, but it does look a bit weirdly colored, I smell it and rub some between my fingers... DIESEL

my idiot friend filled his tank up with diesel!!!

No friggin wonder I couldnt figure out what the hell was the problem, I hooked it up a spare fuel tank with clean gas, she sputtered and choked to life and after about 30 seconds of clearing all that crap fuel out of her she ran just fine!!!

So thats explains why I could get it to run fine off of the carb cleaner but the injectors werent doing the trick, she dont run on diesel!

[catacom225]

And you have people here scratching there head's tring to solve these problems