So, question is, why was I able to fill with the ignition on, and wally wasn’t? To understand why this was led me into a little emersion into On Board Refueling Vapor Recovery (ORVR) systems.
Basically, there are two routes gas vapor takes to vent depending on the condition; when driving or while refueling.
While driving, vapor is routed through the Fuel Cut Valve (42084AC010) (top of tank), to the Fuel Filler (neck) Valve (42084AC010), to the Pressure Control Solenoid Valve (42084FA110), to the Canister, then finally through Canister Drain Valve (42084FA120) to atmosphere.
While refueling, this route changes by the action of sticking the nozzle into the filler neck as it closes the Fuel Filler Valve and closes that venting path. Instead now venting is forced through the ‘high volume’ tank Valve-vent (42084FA161), to Canister, to Drain Valve (42084FA120) to atmosphere.
So, back to the question - Why I was able to fill the tank with ignition on? Basically because my Fuel Filler (neck) Valve (42084AC010) wasn’t closing properly when I stuck the nozzle in, allowing venting through this valve, and subsequently through the Pressure Control Solenoid Valve only when the ignition was on.
I mentioned earlier in my posts that this ‘work around’ stop working. Why? Because the valve common to both venting conditions – the Drain Valve (42084FA120)- failed.
Wally – as a ‘work around’, try disconnecting the vent line on the Fuel Filler(neck) Valve coming from the tank – it’s the one that goes through the wheel well. Then try filling – you shouldn’t need ignition on because now your venting out of that ‘low volume’ line, which is before the Pressure Control Solenoid Valve – which closes when ignition is off. Keep in mind, this is a ‘low volume’ venting line so half throttle on the gas nozzle.
Like me, it does seem your primary issue is with the ‘high volume’ Valve-vent (42084FA161) on top of the tank. I found similar work around to the one I first mentioned using drum sander barrel (aside from cutting a hole in the back floor :smile
. It involves an ‘easier’ method to pressuring the tank - along with a few well placed persuasive hits from a mallet.
The larger single vent line that is attached to the very top of the filler neck goes directly into the tank. (It used to measure atmospheric pressure so that the tank vent valve can open based on Differential pressure). Anyway, you can disconnect and use that line to pressurize your tank and after you’ve removed your back seat, use the mallet to make contact with an area in the centre –above the 'high volume' tank Valve-vent (42084FA161).
Measure your success have having someone monitor the venting from the disconnected large Fuel tank venting line at the canister. It worked for me…for now.
Good luck.
Last thing – do a google using key words “W1860BE emission system”. First few pdf links help me immensely with understanding how this EVAP system works.