Hi, everyone. I have a propane powered Toyota 5fgc25 serial 5fgcu25-74699. First thing in the morning the unit cranks over 15 revolutions or so before it fires up, For the rest of the day it starts first crank. The propane lockoff valve holds vacuum and ive got the vacuum line hooked directly to the intake manifold. It is an older unit with 13000 hours. engine vacuum is about 16 inhg. Any tips or ideas would be greatly appreciated. Thanks.