Propane forklift won’t hot start.

[4570Man]

I have a propane fueled forklift that runs fine when it does run. I’ve never had any problems starting it when it’s cold. And by cold the ambient temperature is in the 80s so it’s not actually cold. Sometimes it will start when it’s warm the problem doesn’t constantly present itself. Sometimes it cranks more than normal and eventually starts sometimes it won’t start at all until it sits for a while. The coil is making spark when it won’t start so I think the problem is fuel related not ignition.

 

[rangerfredbob]

Looks fairly new, what year and what engine? I have some experience but not sure how well it'll transfer to different engines... After '03 it will likely have emissions controls which makes the fuel and governing system more complicated, the emissions regulations got more strict in '07 too...

With those symptoms I would suspect it's either rich or lean but depending on the fuel system troubleshooting might be easy or hard... If it's carbureted I'd suspect a Impco/Woodward CA55 carburetor which is a piston operated thing that's sometimes touchy but at least doesn't have a diaphragm to wear out or break/bend like a CA100/CA200/CA225. One of the dumb things that can happen is the lockoff valve not seating...

 

[4570Man]

Looks fairly new, what year and what engine? I have some experience but not sure how well it'll transfer to different engines... After '03 it will likely have emissions controls which makes the fuel and governing system more complicated, the emissions regulations got more strict in '07 too...

With those symptoms I would suspect it's either rich or lean but depending on the fuel system troubleshooting might be easy or hard... If it's carbureted I'd suspect a Impco/Woodward CA55 carburetor which is a piston operated thing that's sometimes touchy but at least doesn't have a diaphragm to wear out or break/bend like a CA100/CA200/CA225. One of the dumb things that can happen is the lockoff valve not seating...

Someone painted it and actually did a good job. It’s a 2003 with 10,000 hours. It’s a Mazda 2 liter engine.

 

[rangerfredbob]

ok, on that it's likely going to be carbureted and that many hours the mixer diaphragm could have damage from backfiring (happens) or is just sticking closed when it's hot (there's a rubber washer by the fuel cone when it's all the way down) from the oil and goo that separates out of the propane which is worse on propane that comes up from the Gulf mainly from transport in rail cars...

I would take the 4 screws holding the top of the carb/mixer on off and see if there's a bunch of tar in the business end and clean that up with some dawn and hot water. If the vaporizer is one of the simple ones like a NJ I might take that apart (turn off the tank to run it out of fuel and crimp off the coolant hoses then you can take it off) and clean it up too. With that many hours there's bound to be some goo...

Oh and the dumbest thing, the vapor hose between the vaporizer and mixer/carb, if there's any cracks that can cause this too, it's a vacuum withdrawal system so you won't smell a leak...

 

[4570Man]

I haven’t had time to mess with the forklift I’ve been coping fairly well with just using it once per day. It’s occurred to me that it seems less about heat and more about leaving the propane tank turned on for a while. If you turn the propane tank off it always starts or if you start it quickly after its last use it always starts. Leave the propane tank on for like an hour and forget about it. What would let propane leak through and “flood” the engine?

 

[gengine]

Sounds to me the lockoff valve is not seating.

 

[rangerfredbob]

That would be most likely be the carburetor diaphragm being bent, they can warp to a point they well not seat around the fuel cone.

If the lockoff valve wasn't seating then it would possibly empty the tank, I wouldn't rule that out though as it's possible...

One of the stages in the vaporizer/regulator could be having an issue as well if it's full of goo, seen that before.

Propane's heavier than air so it'll stick around and once you start cranking it'll suck more in making the problem worse, to top it off it's harder to light too which is why you might see tighter plug gaps rated for propane engines... sometimes down to like .015"...

 

[4570Man]

Sounds to me the lockoff valve is not seating.

I don’t think it has one unless it’s built into the regulator. The supply hose appears to go straight from the regulator to the tank. This is what the regulator looks like which does appear to have a solenoid valve on it.