another propane prob.

[whiskeymakin]

if any one has any insight on why the engine stumbles and dies around idle let me know what could be the prob.
the whole kit was working fine last year took it off to redo the motor and put it all back together just the way it was before, it runs good if you prime it with gas and start it, revs good to what ever you can rev it to.
the prob is getting the idle down to around 1000, it stumbles and dies. like its running out of fuel or loading up. cant really tell which its doing. as long as you keep it around 2000 or above it runs perfect. its just the close to idle that kills it.
there are no vac. leaks that we could find around the base or anything.
any help is good
thanks

 

[zukiscott]

I say double check for a VACUUM LEAK .....

 

[John Galbreath Jr.]

I say double check for a VACUUM LEAK .....

I know nothing about propane, but can you check for a vacuum leak by spraying ether. It seems like the engine would race when the leak was found.

Opinions?

 

[xjkrawler]

I know nothing about propane, but can you check for a vacuum leak by spraying ether. It seems like the engine would race when the leak was found.

Opinions?

i always just use a soap and water mix..... its prob a vacuum leak.

 

[HotRodpayton]

There should be two ports on the mixer body. Make sure they are capped. Second, did you put any silicone on the intake/mixer gaskets? If the gasket is hard, like a Napa gasket, it wouldn't hurt to pull it off and try it. That was 2 probs I had ???

 

[whiskeymakin]

ok thanks for the replies. the silicone on the gaskets is the only thing i havnt tried. i checked all of the diaphrams today on the mixer, one had a hairline fold in it where the gasket mates up to it that could have been causing a little air to get in. other than that im still stumped. i tried the ether/carb cleaner trick for leaks around the base and body of it. no jump in rpms. the only thing i can think of is the vaporizer has a prob. or the carb is messed up somewhere that i havnt been able to see. the regulator/lockoff is working properly, i cracked the line coming out of it and pulled a vacuume on it, it hissed fuel out. so i assume its working right.
if anybody else has any ideas, throw them out here. im at a loss here. dont know what else to do except just start changing out pieces.

 

[80toyota]

mine was sucking air of all places thru the big hose running between the mixer and carb. I tried eveything with the carb and mixer and the only thing wrong was that damn hose. I sprayed wd 40 and either on it and would rev the motor. I removed it and held it in the air full of water and it leaked like a damn sprinkler.

 

[whiskeymakin]

ill check that but i have the clear braided hose. it could still be the problem tho.

 

[80toyota]

10-4 mine was braided but leaked like hell

 

[HotRodpayton]

There is a part inside the vaporizer that looks like an arm. If it has trash under it, or the arm has swagged over time, it will run bad. They make a gauge to check that, but I don't know where to get one. Precision sales and service in B'ham is the only guy I know that does. Also, have you tried to run the system with no lock off? I don't even run one, it could be acting crazy.

 

[whiskeymakin]

its running perfect today....thanks to hotrods thoughts.....it was the baseplate. i dont guess the ether trick always works???? the intake had been used before and along the way a some threads were stripped and repaired. some of the thread insert stuff was hanging out just a tiny tiny bit, not allowing the base to seal all the way. i grinded it down smooth, got a holley base gasket (one with the 4 holes) siliconed it top, bottom and everywhere i could.... and it started right off the bat, idled perfect, and reved up and right back down like its supposed to. still running a litttle lean tho
thanks for all of the suggestions and thoughts
john

 

[HotRodpayton]

Glad you got er going man