Onan 4000 generator cranks but won't start
Hi all, I have a 2015 Cummins Onan RV QG 4000 generator. It has somewhere between 300-1000hrs (not sure, I've only owned it for about 2 years and it was a previous rental...might not be the origin...
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Still not working...here's an update on what I've tried/checked...
To troubleshoot so far here is what I have done to no avail...
- I have a full tank of gas in the motorhome.
- The motorhome is level.
- Altitude adjustment set to 0 (I am near sea level).
- I checked the oil to make sure there wasn't too much (it is to the low end on the dipstick as most seem to recommend).
- I swapped in a good spark plug to make sure that wasn't the problem, and it didn't fix it.
- I checked the air filter and it seems fine (...even tried starting it without the air filter and it didn't start).
- I changed the fuel filter with a new one, primed it and tried starting it several times and that didn't fix the problem.
- I disconnected all the batteries (and my solar) per someone's suggestion to "reset" the generator. Hooked everything back up and it still didn't fix the problem.
Latest items:
- I removed the fuel line going to the carb and tried to start to see if it was sending fuel to the carb. Yes, plenty of fuel is getting pumped to the carb (so it's not a bad fuel pump).
- Compression check: I've never done this before but I think I did it right. Tough to get at the spark plug hole to screw in the compression check tool but I believe I did get it in there and snug. When I cranked it I got ZERO COMPRESSION registering on the tester. I tried it more than once, disconnecting the tester and then putting it back on and making it snug. Zero compression.
So....what does Zero Compression indicate on this generator and what would you recommend my next steps be?
Summary:
- Yes there is fuel going to the carb.
- Yes the spark plug is sparking.
- No, there is not any compression (...unless I did the test wrong).
Thanks in advance!
Chris
To troubleshoot so far here is what I have done to no avail...
- I have a full tank of gas in the motorhome.
- The motorhome is level.
- Altitude adjustment set to 0 (I am near sea level).
- I checked the oil to make sure there wasn't too much (it is to the low end on the dipstick as most seem to recommend).
- I swapped in a good spark plug to make sure that wasn't the problem, and it didn't fix it.
- I checked the air filter and it seems fine (...even tried starting it without the air filter and it didn't start).
- I changed the fuel filter with a new one, primed it and tried starting it several times and that didn't fix the problem.
- I disconnected all the batteries (and my solar) per someone's suggestion to "reset" the generator. Hooked everything back up and it still didn't fix the problem.
Latest items:
- I removed the fuel line going to the carb and tried to start to see if it was sending fuel to the carb. Yes, plenty of fuel is getting pumped to the carb (so it's not a bad fuel pump).
- Compression check: I've never done this before but I think I did it right. Tough to get at the spark plug hole to screw in the compression check tool but I believe I did get it in there and snug. When I cranked it I got ZERO COMPRESSION registering on the tester. I tried it more than once, disconnecting the tester and then putting it back on and making it snug. Zero compression.
So....what does Zero Compression indicate on this generator and what would you recommend my next steps be?
Summary:
- Yes there is fuel going to the carb.
- Yes the spark plug is sparking.
- No, there is not any compression (...unless I did the test wrong).
Thanks in advance!
Chris
