Propane 4.3 turbo no start need help

[Honky Lips]

Ok. So I bought a buggy with a gm 4.3 vortec engine. Propane fuel system. And turbocharged.

It is a bastard to get started. First I had to replace the engine because it had water in it. And while I have got it to start a couple times. It’s a chore. And not wheelable.

anyone really knowledgeable with propane?

I rebuilt the iMpco model E vaporizer. And put a new diaphragm in the mixer/throttle body. When I press the purge button propane flows.

 

[Adamwende]

Well, there’s only one wire to make the whole system work. I’d start there.

 

[Honky Lips]

Pressing the purge button on the vaporizer sends propane into the throttlebody. It’s getting fuel through but I don’t know if it’s enough or not enough for something but rebuilding the vaporizer seemed really easy and straightforward

 

[Mr Stubs]

Draw through or blow by setup?

 

[Honky Lips]

Draw through. Throttle body/mixer is before the turbo

 

[Mr Stubs]

Have you checked for any air leaks after the mixer?

 

[Byro]

Not sure how that mixer works, my M&M was vacuum operated to pull the diaphragm open. If you have no vacuum it’s not gonna pull the diaphragm open.

 

[ToyotaSub]

What sort of ignition system do you have on it? Hard starting is often base timing issues with propane. How does it run once started?

Post most details about the engine, turbo, etc. Pics maybe.

Also if it's been around a while the mixer might be fucked. The Impco 425 is a wear part. The idle diaphragm tears and they tend to go fat because of that, and they wear out internally too.

 

[ToyotaSub]

Also make sure you have the arm height correct in the regulator. They need to be tweaked normally. If it is not correct it will not work right.

 

[m j]

pics? is the coolant flowing in the reg?

 

[m016324]

pics? is the coolant flowing in the reg?

Agree on looking at this too. Hard starting on propane also can be caused by the mixer being cold. Depending on how cold it is you can actually warm the mixer case some to help make the starting easier.

-ben

 

[2big bronco]

Play with your timing. Start around +10*

 

[ScrewLoose]

Obviously don't use a vacuum lock off on this setup, use electric. Double check the timing it should spin and fire very easily. If it cranks slow your timing is likely a ways off.