Vapor lock drving me nuts..I think

[Curtis Pennington]

I have a WM commander that is given me fits...first thing in the am, it runs like a champ, if you try to start it after you run/after the job it start's right up. However if you wait 10-15 minutes later its beeotch to start. If you wait 45- hour it fires right up. Ive changed the fuel pump, fuel filter, took the air filter off etc. When its acting up, I have to pull it full throttle to get it to start and that takes 3- 10 minutes. driving me nuts!!!!!!! I talk to small engine guy and he said somethin about the diesel bypass...any other suggestions?

Im posting here cuz this room gets more looks and yes I did some searches thats what led me to changing the fuel pump/vapor lock.

Thanks
C

 

[Guest]

If it is vapor lock,then mount that fuel pump away from the machine,maybe under the van,it is getting to hot.

 

[Desk Jockey]

Is the pump near the heat of the unit? Prochem use to mount their pumps on the unit until they had too many problems and pump failures.

Then they changed the installation to a pump located beneath the truck.

 

[Curtis Pennington]

I remounted the new fuel pump to underneath the van..previously it was mounted on the fresh water tank. Thanks to "search" here I eliminated that possibility.

 

[Sticky]

make sure the pump is mounted verticle...they have problems sometimes if they are mounted horizontal...all manufactuers want the pumps mounted up and down with the inlet on the bottom and outlet on top....you probably already know but just thought that I would mention....all manufactuer want them mounted underneath the truck too....IDK if thats just for liabilty purposes or not but thats what they all recommend....

 

[Chads]

I would love to know what the fuel pressure was at in the morning and after it has ran and is having problems my guess ist there some other type of a switch or valve on the engine did you say it was a diesel or is it gas motor. I know on my briggs and stratton that there is a kill switch on my carb when I turn off the key a plunger in a soilinoid pops out and plugs the hole of the primary jet killing the motor you might have something like this on your machine who know vapor lock is not likey your prob though. put a pressure guage on your fuel line and find out.

 

[renegade_cowboy]

I have a WM commander that is given me fits...first thing in the am, it runs like a champ, if you try to start it after you run/after the job it start's right up. However if you wait 10-15 minutes later its beeotch to start. If you wait 45- hour it fires right up. Ive changed the fuel pump, fuel filter, took the air filter off etc. When its acting up, I have to pull it full throttle to get it to start and that takes 3- 10 minutes. driving me nuts!!!!!!! I talk to small engine guy and he said somethin about the diesel bypass...any other suggestions?

Im posting here cuz this room gets more looks and yes I did some searches thats what led me to changing the fuel pump/vapor lock.

Thanks
C

Not sure if this will help. I was dealing with the same exact thing. I couldnt start it after it ran for a period of time. So after doing almost everything to it. I finally replaced the positive and negative wires from the battery to the machine. After that it starts everytime, even after running for a long period of time. The wires had very little corrision, but i guess enough to causes it not to start. The funny part it was turning the engine just fine. Figure that one out.

 

[Jack Zipper Zerkie]

Don,t know if this will help but had a same type of problem with my Hydramaster470D its only taken me 6years to fix it. All the heat rises from the heat exchange and cat conveter to the carb. Easy fix ram 1.5" hose from the carb air intake with hose clamp 3ft. out to the front panel at the side door. Now it runs the way it should, but not by their design. Cheap fix if it works for you. jack z.

 

[Curtis Pennington]

I would love to know what the fuel pressure was at in the morning and after it has ran and is having problems my guess ist there some other type of a switch or valve on the engine did you say it was a diesel or is it gas motor. I know on my briggs and stratton that there is a kill switch on my carb when I turn off the key a plunger in a soilinoid pops out and plugs the hole of the primary jet killing the motor you might have something like this on your machine who know vapor lock is not likey your prob though. put a pressure guage on your fuel line and find out.

It is gas but on a kohler there is "diesel" by pass selonid/valve not sure why or what it does but I was told to check that...thanks

 

[Curtis Pennington]

Don,t know if this will help but had a same type of problem with my Hydramaster470D its only taken me 6years to fix it. All the heat rises from the heat exchange and cat conveter to the carb. Easy fix ram 1.5" hose from the carb air intake with hose clamp 3ft. out to the front panel at the side door. Now it runs the way it should, but not by their design. Cheap fix if it works for you. jack z.

Wow Ill try anything including that...thanks

 

[Curtis Pennington]

I have a WM commander that is given me fits...first thing in the am, it runs like a champ, if you try to start it after you run/after the job it start's right up. However if you wait 10-15 minutes later its beeotch to start. If you wait 45- hour it fires right up. Ive changed the fuel pump, fuel filter, took the air filter off etc. When its acting up, I have to pull it full throttle to get it to start and that takes 3- 10 minutes. driving me nuts!!!!!!! I talk to small engine guy and he said somethin about the diesel bypass...any other suggestions?

Im posting here cuz this room gets more looks and yes I did some searches thats what led me to changing the fuel pump/vapor lock.

Thanks
C

Not sure if this will help. I was dealing with the same exact thing. I couldnt start it after it ran for a period of time. So after doing almost everything to it. I finally replaced the positive and negative wires from the battery to the machine. After that it starts everytime, even after running for a long period of time. The wires had very little corrision, but i guess enough to causes it not to start. The funny part it was turning the engine just fine. Figure that one out.

ten foe

 

[Ron Lippold]

its all the alcohol in the gas. It boils at 180 and will give you problems. If you have the ability to cycle the pump a few times that might help the problem

 

[renegade_cowboy]

[quote="C Pennington":2ncvl62o]I have a WM commander that is given me fits...first thing in the am, it runs like a champ, if you try to start it after you run/after the job it start's right up. However if you wait 10-15 minutes later its beeotch to start. If you wait 45- hour it fires right up. Ive changed the fuel pump, fuel filter, took the air filter off etc. When its acting up, I have to pull it full throttle to get it to start and that takes 3- 10 minutes. driving me nuts!!!!!!! I talk to small engine guy and he said somethin about the diesel bypass...any other suggestions?

Im posting here cuz this room gets more looks and yes I did some searches thats what led me to changing the fuel pump/vapor lock.

Thanks
C

Not sure if this will help. I was dealing with the same exact thing. I couldnt start it after it ran for a period of time. So after doing almost everything to it. I finally replaced the positive and negative wires from the battery to the machine. After that it starts everytime, even after running for a long period of time. The wires had very little corrision, but i guess enough to causes it not to start. The funny part it was turning the engine just fine. Figure that one out.

ten foe[/quote:2ncvl62o]

How old is your machine? It does sound like the same exact problem I had with my machine, please update if you do replace the wires. Like I mentioned the engine was turning just fine it just wasnt starting. I too thought is was a fuel or spark issue. I had to wait almost an hour for it to start. I seriously went through everything on the TM. The cables was one of the last things.

 

[Curtis Pennington]

Its a 5 year old WM commander bout 900 hrs been happy with it overall. Only had to fix some "normal" stuff that wears and tears over time.

 

[Shane T]

Are you sure its a fuel related problem? Do you have spark at the plugs when it won't start? If not check kill switch wiring for loose connections or if a wire has been worn through from vibration or heat. I once had a bad wire from the low oil pressure switch.

 

[GeneMiller]

Check the wires to the pump. They have to be the correct size other wise the pump will run hot and over time could cause a starting problem. If they are the right size try replacing them with new ones. When it's hot and won't start you can pull the fuel line from the out side and visually check to make sure that fuel is flowing. Pumps generally work or they don't but a hot one might not flow properly. They may even have a thermal switch. Hope this helps

Gene

 

[renegade_cowboy]

You machine running?

 

[The Bull]

We deal with vapor lock a lot here in Las Vegas. Call me in the morning and I can give you a couple of ideas to try.
Not too early 3 hours difference :mrgreen: . 702-265-0747
Rick

 

[The Magician]

How old is the battery? Check to see if your getting 14 volts when the engine is running maxium speed. I say its a battery/voltage problem.

 

[Curtis Pennington]

Thanks fellas..still driving me nuts..lol

 

[Shane T]

My money still says its electrical and not fuel related but if you still think its vapor lock try using a turbo fan to blow cooler air into the van while operating?

 

[FloorPizza]

This is probably a worthless post, but it has always helped me when diagnosing engine problems...

An engine requires three things to run: air, fuel, and ignition.

Diagnose by process of elimination. Is it getting air? Correct amount? Correct temp? (You don't want air that is hotter than ambient as the air source the engine is using for combustion).

Is it getting fuel? Can you remove the fuel line downstream from the fuel pump and verify that the carb (or fuel manifold if it's a FI engine) is getting liquid gas during start?

Last is spark. If you aren't supplying the ignition system with enough electricity during start, you'll either get no spark at all, or only spark to some, but not all, plugs. Lots of different ways to diagnose this one. All of which require you to be careful.

As long as the engine is getting air, fuel, and ignition it has no choice but to run (as long as it's developing compression, but that's usually really easy to diagnose).

Hope this helps.. it does help me, but to quote the wise man Forrest Gump, "I'm not a very smart man, but I do know what an internal combustion engine is, Jennay".

 

[Brian R]

As far as getting air goes. I was told that if you take the body parts off the unit it WILL NOT get enough air. It needs to get it from the front intake. Go figure. I was going to take off the sheet metal parts to make it run cooler.

I had this exact same problem the entire time I owned the POS.

With that said. Do what I did with my WM HO with 1000 hours on it.

Give it the hell back to them.

when it worked, it was great.
When it didn't....it didn't...and it didn't often.

Most of that work was under warranty but after that ran out, I was screwed.

Wasn't worth the hassle.

 

[Brian R]

Oh and you can show them that last post of mine.

They will know who I am.
Bastards.

 

[Chris Sheldon]

What type of fuel pump are you using?

I have gone to these and haven't had any problems as of yet.
http://www.racerpartswholesale.com/prod ... Fuel_Pumps

These pumps have a solid impeller instead of a diaphragm which really seems to help with the vapor locking issues. You may need to install an adjustable fuel regulator if the pressure is too much for your engine.

You may also try to insulate your fuel lines to keep them cooler; I grew up in Las Vegas and we used to wrap our fuel lines with tin foil to keep our muscle cars from vapor locking! ha ha It worked well.

 

[Larry Cobb]

Curtis;

Eliminate the possibility of no fuel !

Buy a can a of starter fluid, and see if that cures the problem.

Then, you will know if it is lack of fuel.

Work from there.

Larry

 

[Shawn Forsythe]

I think the discussion you had with your mechanic friend may have a lot of validity.

The fuel solenoids on the WM Commanders are the most often cause of fuel difficulties in those units. Fortunately they are easy to diagnose, and not too expensive to replace. Many users bypass the valve altogether, though WM strongly urges users not to do so.

 

[Gary Bethel]

Curtis, I am not sure if your engine has a fuel shut down solenoid, but if it has, a lot of manufacturers wire their kill switches through them. Which means if one of your kill sensors is activated it will not allow fuel through. Now seeming that the engine is starting when cold but really difficult when hot, this points to either fuel supply or the oil pressure switch.
If the oil is getting too hot it gets too thin and will no longer activate the oil pressure switch. If you can not start the engine, after a period of shut down the oil will cool down, gain a little more viscosity, then it will allow you to start.
Is it possible that you were running low viscosity oil during winter which is now proving to thin in the hotter months.
If it proved to be the oil switch, you can put an oil pressure override switch in which allows the engine to fire and build oil pressure. Once this has happened you drop off the override switch.

Gary.

 

[Shawn Forsythe]

Curtis, I am not sure if your engine has a fuel shut down solenoid, ...

Gary,

What I am referring to is not on the engine. White Magic puts a fuel solenoid valve on the lower left hand frame rail, near the front of the machine on the Commander units. The purpose is to provide a positive fuel flow shutoff when the keyswitch is off. I've observed they typically last a year or two.