I had major issues with my gas cap, and tested everything and induced POOGS so I can tell you a few bits.While you're checking, make sure the vac hose on the petcock is staying dry. Don't think I've ever had POOGS, but I've had a couple unexplained stalls and bogs. Closest I've found and had to fix has been the leaky petcock diaphragm.
We need an acronym for that, kind of a pain to keep typing all about the diaphragm. How about WTFHTMO syndrome, or DWMG. Mmm, too obscure.
WTF Happened To My Oil
Dude Where's My Gas
POOGS happens when the Vapor Out line is plugged (not open to atmospheric pressure). It runs up through gas cap so blow through the rubber hose and make sure it is clear.
To test I ran the Vapor Out and Fuel Return lines from the tank to these catch bottles.
It caused POOGS because the Vapor Out line was in an airtight bottle, no way to vent to atmosphere.
Solution: Drill a hole in the top of its catch bottle.
If you fill gas tank into filler neck, gas will run the wrong way down the Fuel Return line and get into the Vapor Canister. Very easy to do, I know because my second catch bottle from Fuel Return often collects gas. Not good. I’m not sure the Separator Pump can handle that.
So I pulled out the Canister and checked there was no liquid gas inside, but if gas did get in I think it compromises its functionality thereafter.
So if the Separator Pump is not working, allowing the Vapor line to be open to atmosphere, POOGS can happen.
Testing the separator pump:
- Disconnect the Vapor Out hose from the separator, and inject about 20 ml of gasoline into the separator through the hose fitting.
- Run a hose from the Fuel Return fitting on the Separator and hold the open end up level with the gas tank filler opening.
- Start the engine, and let it idle.