Need Help

redmt · #1 (**permalink**) 08-31-2010, 01:44 PM

This is as good aplace as any if not better!

Does anybody have experience with propane fueled engines? I have a 2300cc Ford powered generator running on propane. It goes against all the norm on a hot start. It won't start without a shot of starting fluid above 80 degrees. It starts nearly instantly in cold weather. I've been through everything I can think of. Spark, timing, air mixer, 3 stage regulator, everything. It runs perfectly hot or cold. It just won't start without a little shot above 80. Any Ideas?

John

Z-linkCobra · #2 (**permalink**) 08-31-2010, 02:36 PM

John, Talked to a buddy of mine that is somewhat fimiliar with propane stuff. He asked about a choke. Propane carbs dont have a float and rely totaly on vacuum. He said take the air cleaner off and put your hand over the top of the carb. Crank it over a bit and then pull your hand off..if it fires right up then theres your problem. In the hotter weather the propane boils off and you have no liquid at your regulator...which is what it needs.

With that being said, it may have a choke on it. The settings could be wrong and the choke not working in warmer weather.

Of course hes just throwing stuff out there with what little info he has.

Gene

redmt · #3 (**permalink**) 08-31-2010, 02:58 PM

There's no real "choke" It has a variable venturi that slides up and down in the carb/mixer. It acts the same with the old one and the new one , (Impco 55) If you try and manually choke it down it will aaalllmmossst start. Just the slightest hint of starting fluid and it's running perfectly. I keep coming back to fuel volatility but the propane co. says no changes for ever.

trularin · #4 (**permalink**) 09-01-2010, 05:26 AM

Propane is more of a gas when it is hot than when it is cold.

I think you are so lean when the engine is hot, the engine can not fire the vapor.

Because the manifold and engine parts are warm, the gas thins out making it necessary to have more to get the same as when it is cool or cold.

Just my opinion.

redmt · #5 (**permalink**) 09-01-2010, 07:58 AM

Quote:

Originally Posted by trularin

Propane is more of a gas when it is hot than when it is cold.

I think you are so lean when the engine is hot, the engine can not fire the vapor.

Because the manifold and engine parts are warm, the gas thins out making it necessary to have more to get the same as when it is cool or cold.

Just my opinion.

I think you are probably right on. Now how to cure the problem? Everything is new and within spec. Carb/mixer, regulator, hoses, shut off valve , everything. I follow the theory of vacuum in the engine breaking the 3rd stage of the regulator. The motor has 180 lbs. plus compression. There is plenty vacuum at the carb during cranking. I still keep coming back to a fuel volatility issue.

John

trularin · #6 (**permalink**) 09-02-2010, 05:46 AM

May I suggest the reverse of the military in winter.

When the hummer was being designed, they offered a cold weather kit that literally shot ether into the intake for a sec. If the kit was installed, the driver/operator simply pushed a button and waited until a red light went out. Then he started the Hummer.

Is there a way to get something like this for your application?

redmt · #7 (**permalink**) 09-02-2010, 11:08 AM

It fires right away with the ether, but it REALLY doesn't like it. Worst detonation noise I've ever heard. Luckily our power doesn't fail near as much in summer as winter. I would just like it to work correctly. Good thing it doesn't have the auto exercise enabled.