Looking for some help with a Mitsubishi FGC25K (s/n AF82D01804). Sometimes when it starts it runs at a very slow idle. I don't know the speed but it seems to run slower than the starter motor turns the engine over at. Usually within 5 minutes or less it eventually will come up to a normal idle speed all of a sudden. The time frame at which it does this varies. It runs fine after that and will typically start and run fine if it is used on a regular basis throughout the day, but not always. I haven't had any issue with it not starting it just won't ramp up to speed like it should.

Thinking it was a fuel related issue I replace the Impco Cobra vaporizer and the filter in the lock-off valve. That did not solve the problem. Put a different LP bottle on it as well with no improvement.

I've tried various things like squeeze and/or remove vacuum lines, wiggle wires, press the gas pedal and the only thing that seems to make a difference is squeezing the outlet of the vaporizer. The engine will pick up speed just a tiny bit (still not anywhere near a normal idle speed) if you squeeze it just right or it will kill the engine if you squeeze too much.

I'm looking to know what to try next??? Thanks!