Cold Weather Starts with Propane

[Mowingman]

I am located north of Dallas. From my experience with our school buses, it is harder to start propane engines in cold weather. We have about 60 propane-powered school buses. In cold weather, say below 40 degrees, it takes a LOT of cranking to get them going in the morning. The newest buses have a wait- to- start feature on them. It takes about 12 seconds for the light to go off, then they do start with somewhat less cranking. I am not sure what exactly happens during that wait to start period of time.
If the batteries are even a little low on charge, you can forget about starting these things on a cold moring without a jump.

[Leaf Jockey]

Originally Posted by ed2hess

Well this morning at 32F it wouldn't start so I took the hose off and sucked on it and the unit started right up. This is simple case of needing a little more vacumn. So where to I manufacture more vacumn? We first tried to use the port on the sepecial propane carb then we hooked to the fuel pump. So if I hook to the vac line going to the fuel pump will I get more vacumn?

By the way after sucking on it to get it started I hooked the hose back
up to the fuel pump and then it continued to run. I don't want to suck on the hose all day.

I'm curious what model regulator you are using. On certain models, everything you described can be explained by a incorrectly adjusted "idle" screw on the regulator.

Scott

[Terry Metro Lawn]

Originally Posted by Marek

Arbor, I hear you are looking into some propane trucks ? Do you think it will be to your advantage being our propane costs here are so high ? Are you also looking into propane powered mowers ?

Roush has some of their demo units on sale if you're interested.

PM me is so.

[ed2hess]

Originally Posted by Leaf Jockey

I'm curious what model regulator you are using. On certain models, everything you described can be explained by a incorrectly adjusted "idle" screw on the regulator.

Scott

Reg is a Beam Model T60...

[Terry Metro Lawn]

Originally Posted by Mowingman

I am located north of Dallas. From my experience with our school buses, it is harder to start propane engines in cold weather. We have about 60 propane-powered school buses. In cold weather, say below 40 degrees, it takes a LOT of cranking to get them going in the morning. The newest buses have a wait- to- start feature on them. It takes about 12 seconds for the light to go off, then they do start with somewhat less cranking. I am not sure what exactly happens during that wait to start period of time.
If the batteries are even a little low on charge, you can forget about starting these things on a cold moring without a jump.

That "wait" is the purge cycle and it's very important as you've discovered.

[Mowingman]

Thanks. Now, what does the purge cycle actually do?

[Terry Metro Lawn]

Originally Posted by Mowingman

Thanks. Now, what does the purge cycle actually do?

Here you go:
http://www.cleanfuelusa.com/Portals/...ers_manual.pdf


It says it better than I can.

For what it's worth, Texas State Technical College offers free technical courses on AutoGas applications.

I just attended one in Birmingham, AL and, although I've been in the propane business over 35 years, I learned a bunch. It's worth it.

[KrayzKajun]

Originally Posted by ed2hess

I don't want to suck on the hose all day.

I couldn't resist. Great choice of wording. Lol on a serious note. How are u liking the propane powered machines?
Posted via Mobile Device

[ed2hess]

Originally Posted by KrayzKajun

I couldn't resist. Great choice of wording. Lol on a serious note. How are u liking the propane powered machines?
Posted via Mobile Device

I really dont know why I am changing the units over. We bought two used units that both had propane then I took a 2000 hr unit that I put a short block on and converted it. We think maybe it might give us a little edge on some commericial properties or at least we are on par with the big guys. With the tnks full the units really float along, meaning front is really light. The units seem to have more hp but don't know if that is true. I hoped we could save a little money but that didn't happen unless I can go longer between oil changes. I do kinda hate luging the tanks in every week
to get propance when the gas place is 110F in the sun. Some guys coment that we must be really rolling in the dough because we got propane on but whatever.

[Terry Metro Lawn]

Originally Posted by ed2hess

I really dont know why I am changing the units over. We bought two used units that both had propane then I took a 2000 hr unit that I put a short block on and converted it. We think maybe it might give us a little edge on some commericial properties or at least we are on par with the big guys. With the tnks full the units really float along, meaning front is really light. The units seem to have more hp but don't know if that is true. I hoped we could save a little money but that didn't happen unless I can go longer between oil changes. I do kinda hate luging the tanks in every week
to get propance when the gas place is 110F in the sun. Some guys coment that we must be really rolling in the dough because we got propane on but whatever.

Depending on the unit, weight is added to the front to balance. The conversions don't necessarily weigh more, but depending on where you mount the tank(s), it can change the center of gravity.

The problems you're experiencing are (unfortunately) very common for those attempting conversion on their own. I deal with this almost daily. There are entirely too many companies using propane successfully to discount it's effectiveness in not only saving money, but helping the environment and reducing our dependence on foreign oil.

Ed, you live in Texas where, with all the incentives, you could have your conversions done without charge. I'd be happy to send you the info.

I'm not sure why you are lugging tanks around. Typically we supply a locking rack and tanks to exchange.

Ed, you're working entirely too hard! ;-)