Good morning,
Generator: 2001 7000 CMM EFI 7HGJAD-2139A, spec A.

Code 15 - generator is unable to provide AC with a frequency above 54Hz.

Randomly, the gen will start and run slow, then code 15. This is completely random. Ran Friday through Sunday at a race with no issues. I picked up the cheap HF Killawatt meter, and when running well, it has perfect 120v and 60hz.

The following Friday night at races, it started, smoked, code 15. Saturday morning back at home, it started right up and ran fine for an hour.

Ran it last weekend for 2 days and no issues. This past Saturday, same thing, code 15, and had to use the little generac generator.

I did put new plugs in a few weeks ago, and the last two 25 gallon tanks of fuel have been 91 octane, no ethanol.

Ideas?

Thank you,
Clark

Sounds like the throttle body control solenoid isn't opening up properly. Have you tried cleaning the throttle body and intake system including the filter?

It has to maintain 3600 rpm on gas generators, so a lack of air going into the engine has to be the issue.

sounds like code 15 is a byproduct of the engine lugging down.

quote:

Originally posted by Don Higgins Crew Chief Pro Software:
Sounds like the throttle body control solenoid isn't opening up properly. Have you tried cleaning the throttle body and intake system including the filter?.

Ive run 2 large cans of seafoam through it over the last 2 seasons.
Acc to the manual, it has a pressure regulator vs solenoid (LP). pn 147-0867, but I cannot locate one available for sale anywhere.

I do have a new fuel pump coming as it is possible that it isnt putting out 45psi reliably.

Change the fuel filter

Monitor fuel pressure

Put a Tee in the fuel pump to T-Body line and hook up an EFI pressure gauge

Normal is in the 45lb range

Fuel pressure and volumn can be an issue....pump, lines etc,,,
There now is a relay kit Onan released for
EFI units to relay the pump....but that is for code 36 shutdowns from board issues

The list of things that can cause trouble with these machines is longer than my arm....

I never had any issues with the EFI components them selves...

That is an old machine and I have recently had 3 people with older EFI machines with random code 47 shutdowns....never found the problem...

I check all the engine mechanical things.....valve lash and condition....heads fail regularly....

Ignition coils randomly fail....old machines have no sensor in the exhaust.....newer machines will shutdown if one cylinder stops firing and trigger a code indicating that

You might be having that exact problem....ignition coil failing randomly or when hot....engine speed drops and it shuts down in a code 15....

The only way to find these things is to baby sit it

I left machines running outside for hours where I could hear it to try and be there when it starts doing whatever it's doing....

I'm glad I am not doing them everyday anymore but am still getting a lot of messages, calls and do a few jobs when they pop up....

Thanks! Fuel filter and hoses were replaced after I put it back into the trailer in May.

I wish I had thought of replacing the coils when it was out.... it is a bish to get out of the gooseneck at 300lbs.

It does not randomly shut down after it has been running, just randomly will not start and continue running from cold....

I'd be looking at the fuel supply...

Pressure is critical in those and the pumps can be the problem...

The coils don't cause a problem like you are now describing....not starting cold...

I know the difficulties all to well on everything with an Onan name on it....

quote:

Originally posted by SCDIV1:
I'd be looking at the fuel supply...

Pressure is critical in those and the pumps can be the problem...

The coils don't cause a problem like you are now describing....not starting cold...

I know the difficulties all to well on everything with an Onan name on it....

Thank you! We've talked briefly on the phone and your advice has already saved me time and money.