Guardian propane generator hard starting. At 20 F backfires and won`t start. Goes to overcrank.

SOURCE: Generac Guardian 17.5KW Generator dies

If this is one of the big "taco cart" portables you need to check that the vent on the gas cap is open when you're running the engine. In the center of the gage on the gas cap is a little knurled knob, turn it counter clockwise (lefty loosey), about a half turn or so and run the generator.
If that doesn't solve your problem add to it here, otherwise please give me a rating I'm trying to build a little credibility here and could use the help.
Carl

mamicheddy

• 79 Answers
• Posted on May 19, 2009

SOURCE: guardian rv generator

Your control board is faulty. Try to power up the ingnition coil as well as your fuel pump. If this does not get the engine running then you have major engine problems.

SOURCE: Attempted to start Generac Guardian 15 kw air

I work on these every day. Its either gonna be the rotor or stater, the voltage regulator, but most likely its a bad stepper motor which is the throttle motor, or control board. Thats all that could be causing that so its one of those. If its the rotor or stater thats bad it causes the generator to RPM up because it thinks its not producing enough power due to that. I had the same problem with the same one we just fixed and it was the slip rings on the end of the rotor so bad rotor.

SOURCE: My generator runs automatically once a week. It

disconnect the battery and try again.

SOURCE: natural gas generator will not start. 4 years after installation.

very likely a fuel problem. First pull the air cleaner cover off and try choking the engine by putting your hand over the intake partially choking it. If this don't work then go Down on the bottom right hand side behind the battery you will see a fuel regulator on top of it is a fuel solenoid with 2 wires coming off it. Below the fuel solenoid you will see 2 -1/4" pipe plugs one on top of the other. If you pull the top one out and gas comes out then you have fuel up to the solenoid. If you pull the bottom one out and crank the engine then you should get gas out of the bottom one. If you don't then make sure you are getting 12 vdc to those 2 wires during cranking. If you do then You are going to have to pull the 4 screws out of the solenoid and pull the solenoid off and make sure you the seat on your solenoid valve is not sticking. If all this checks out and you are getting fuel out both 1/4" pipe plug holes, then you will need to see if you have a spark at the spark plugs, if you don't then something is shorting out your ignition coils. Disconnect wire 18 from its terminal located above the oil cooler. If the engine starts and runs with this wire disconnected then you need to trace this wire back to the control panel and see whats causing it to ground out.

Let me know if this helps.