Vmax FG:
Impco Fuel System on Vmax FG duel fuel Range

GQ 4 Y engine will not run on LPG , have changed complete sytem from tank to carb and still will not run,
The only way I can get these units to run on LP is to put the fuel switch in the center position. Run the gasoline out of the carburetor. Flip the fuel switch to LP. Put spray fuel down the tube from the air filter. The engine will finally pick up LP fuel. Some times it will restart with just a turn of the key, some times it takes some spray fuel from the air filter tube. Other times it will not start at all. I've tried adjusting the rich/lean screw both ways. If you go either side of the factory settings the engine will not run at all.
On gasoline, with the air filter installed. The tube from the air filter to roll bar tube off. You have to turn engine over with your hand almost completely stopping the flow of air into the engine. When the engine starts to fire you pull your fingers from over the air filter suction hole one at a time. The engine will run then. Sometimes engine will restart with just turning the key. Most of the time you have to stop up the air flow to the engine. I've tried adjusting the idle adjustment screw in and out with very little affect. these are new forklifts with under 50 hours.
Thanks Jody
  • Posted 24 Sep 2016 01:23
  • Discussion started by cameron_b
  • Georgia, United States
Showing items 1 - 2 of 2 results.
Thank you will try this.
  • Posted 27 Sep 2016 03:59
  • Reply by cameron_b
  • Georgia, United States
If that has the Impco model J or Cobra there are 2 versions, one with a blue spring on the valve and one with a orange spring. The orange one requires less vacuum to start the fuel flowing. If it has blue and should have orange it would cause that symptom.
  • Posted 24 Sep 2016 08:59
  • Reply by mrfixit
  • New York, United States

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