Propane problems
Propane problems
Hi all I am new to the forum and am curious if others have encountered a similar problem. I have a 1984 E350 Ford motorhome with a 460 or 7.5 Ltr. with a Vialle D regulator it also runs on reg gas as well. My problem is that on several occasions now while travelling on the highway on propane fuel at 95-100 Kms. Per hour the engine suddenly seems to loose power especially on a hills. When I decelerate to pull over the engine wants to stall or actually will stall once pulled over. After the vehicle cools down it seems to run normally again. Any ideas?
Re: Propane problems
I'm not sure if the Vialle on your vehicle is the same but just in case here's some things to consider.
When I was working at the local (Australian) Ford dealership we had cars come in with similar sounding issues. We did a couple of checks before anything else.
1. Water level in radiator (basic but it is amazing how many people forget to check it).
2. Check and blow out the idle valve in the Vialle.
3. Check the drain cock on the Vialle and make sure no water is getting into parts it shouldn't.
4. Clean the throttle body.
5. Make sure the stepper motor (in the LPG vapour line) is functioning properly.
Doing these things always found the issue most often low coolant level but the idle valve was an item that was serviced at each service because they could, and did, clog up.
When I was working at the local (Australian) Ford dealership we had cars come in with similar sounding issues. We did a couple of checks before anything else.
1. Water level in radiator (basic but it is amazing how many people forget to check it).
2. Check and blow out the idle valve in the Vialle.
3. Check the drain cock on the Vialle and make sure no water is getting into parts it shouldn't.
4. Clean the throttle body.
5. Make sure the stepper motor (in the LPG vapour line) is functioning properly.
Doing these things always found the issue most often low coolant level but the idle valve was an item that was serviced at each service because they could, and did, clog up.
Fuel flow requirements calculations
Engine air flow requirement calculation: CFM = Cubic Inches x RPM x Volumetric Efficiency (VE) ÷ 3456
Engine air flow requirement calculation: CFM = Cubic Inches x RPM x Volumetric Efficiency (VE) ÷ 3456
Re: Propane problems
Hi storm not sure about the stepper motor you are referring to but will look into it. Rad coolant levels are fine. Thanks for the comments
Re: Propane problems
Storms ideas were all good. The stepper motor he is referring to is an electronically controlled power valve installed in the vapour line leading to the mixer. It is used on electronically fuel controlled systems with a simple computer that monitors an oxygen sensor and adjust the power valve to the correct mixture. Being an older unit you may not have this. Yours may just be a manual adjustment.
The coolant level or a blockage in the coolant supply line is the most common reason for power loss. The moment the power loss occurs you should quickly open the hood and see if there is frost or ice on the regulator. If there is then a problem in the coolant supply is the problem. Depending on the routing of the coolant supply hoses a plugged heater core is one consideration. A thermostat stuck open is another.
One other item to consider is the fuel filter. It may be restricting the fuel flow partly, then ices up at an increased load. Check for this by quickly checking the fuel lock off that is right next to the regulator for any signs of frost. You will have to be quick as underhood heat will dissolve any frost rapidly once you stop.
Lastly check the supply lines leading from the tank to the regulator. You may be getting a restriction along the line somewhere. Again, just look for any signs of frost.
The coolant level or a blockage in the coolant supply line is the most common reason for power loss. The moment the power loss occurs you should quickly open the hood and see if there is frost or ice on the regulator. If there is then a problem in the coolant supply is the problem. Depending on the routing of the coolant supply hoses a plugged heater core is one consideration. A thermostat stuck open is another.
One other item to consider is the fuel filter. It may be restricting the fuel flow partly, then ices up at an increased load. Check for this by quickly checking the fuel lock off that is right next to the regulator for any signs of frost. You will have to be quick as underhood heat will dissolve any frost rapidly once you stop.
Lastly check the supply lines leading from the tank to the regulator. You may be getting a restriction along the line somewhere. Again, just look for any signs of frost.
Re: Propane problems
One other thing to check. Make sure there is nothing blocking the air vent to the front diaphragm. It is located on the front cover where the Reg has the name Vialle cast in it. The vent is a threaded opening on the front lid. In some cases a short tube might be attached and curved upwards. Any water or foreign object can plug this tube preventing the front diaphragm from moving. The tube was used to prevent ram air or a draft from entering the diaphragm while moving. Pressure in the vent opening will prevent the diaphragm from moving properly. If there is a tube on it remove it and make sure it is clear. If no tube use a piece of wire or a small diameter blunt metal rod to check inside the vent that there is no dirt or a stone lodged in the opening. Be gentle and don't use anything sharp as you could damage the diaphragm.