FM2Q-36 Fault

[siai47]

Came out this morning after refueling my Cavalier from empty to find a green flashing light on the fuelmaker. The fuelmaker was shut down and the Cavalier was full. I attached the fuelmaker to another vehicle and pushed the start button. The fuelmaker started, did it's purge cycle, and sounded like it was starting to fill---however it was doing anything. I couldn't hear any sound of fuel moving through the fill port. In addition, it sounded like the fuelmaker was leaking internally. There was no smell of gas but the compressor was running with the gas recirculating inside the unit. No gas flow into the fuelmaker was observed on the gas meter. I removed the compressor head, checked the "O" rings for damage. When I spun the compressor by hand, air was coming out of the small opening that connects back to the housing with a small metal tube. Everything seemed OK but I don't know if air should have come out of the opening. I reassembled the compressor and restarted it without attaching the fuel outlet hose. The unit ran about 10 seconds and shut down with a solid yellow "tank fuel" indication just as it should. I then reattached the fuel outlet hose to the fuelmaker and filled the next vehicle with a sucessful, normal fill and shutdown. What might be going on? Is there a pressure relief valve that could have opened? And if there is, why would it have still been open with zero pressure and then close and operate normally?

[cngaz]

Re: FM2Q-36 Fault

by pulling out the compressor you may have jared a sensor or valve in the controls module. Eventually it will probably happen again.
Get your manual and hold down the buttons and read what error code it set when it shuts down the next time it happens.

[siai47]

Re: FM2Q-36 Fault

Thanks for the reply--I will check the stored faults next time and report what they are. It's unlikely that it will heal itself.

[siai47]

Re: FM2Q-36 Fault

Finally figured it out. The fault was a timeout due to excessive fill time. Over five hours for a quarter tank in a Cavalier I could smell some gas but wasn't sure where it was coming from because the fuelmaker cooling fan blows it everywhere. Turns out the "O" rings in the tube running from the compressor outlet block back to the housing had failed. They were leaking just enough to allow some pressure rise so the fuelmaker didn't shut down. However, they were leaking bad enough that even with the hose disconnected from the fuelmaker, it would not reach full pressure. New "O" rings fixed the entire problem and the fuelmaker runs normally.

[siai47]

Re: FM2Q-36 Fault

OK-Blew out the "O" rings that I put in the unit. Worked for a couple of days but failed again. Question---does anyone know the correct size for the four "O" rings on the tube running from the compressor output block back to the housing? I used US (inch sized) "O" rings but was wondering if the correct parts are metric. The rest of the unit is metric so it would be natural that the "O" rings are also. When the "O" rings get this small, it is hard to tell the difference between the two.