stage 1 v8 wont start.

[muddyjames]

I have a mate who is trying really hard to get his stage 1 V8 going.

It was running ok when he bought it earleir on this year. then in the summer the mainly on hot days the lpg gas was a bit iffy in the way it didnt idle very well and sometimes stalled.

then 1 morning about 8 weeks ago it wouldnt start. After alot of trying the starter motor burnt out so he got a new one. Landy started 1st time.

drove around for 3-4 days then the cold snap kicked in. After that it wouldnt start. He has spent £70-£80 on new shiny ht leads and got a new dizzy cap. tried the ht leads in various starting positions in the right firing order and nothing. We got a hint of life when we got cylinder 1 to top dead centre and he had the spark plug on the engine looking for a spark. it fired up for a brief second but as my mate was holding the ht lead i stopped it. after that it wont go again.

He is getting a bit [!Expletive Deleted!] off now and run out of ideas. Can any one help us? More ideas needed.

It has always struggled a bit to start on lpg though.

By the way. We cant try it on petrol until his new petrol tank arrives as he found out on sunday the tank leeks!

[H]

arnt lpg converted vehicles supposed to be started on petrol and then switched over to gas? I know mine wont start on gas alone.

H

[Jim-Willy]

arnt lpg converted vehicles supposed to be started on petrol and then switched over to gas? I know mine wont start on gas alone.

H

Most not all.

[yer auld aunt nelly]

nelly used to start an run on lpg from cold,back to your mate start at the begining and set the leads,the timing,check the carbs(if you have ad em apart) you wouldnt believe wot people assume that they ave checked.Short of it being its a v8 mate should be able to "start in a storm"    

[v8kenny]

My 110 V8 LPG would start on gas provided you primed the system by switching ignition on and off three times then start on half throttle
Can you hear the gas solenoid kicking in when you turn on ignition ?

[muddyjames]

when you say set the leads? We have put them in the right orderand and found top dead centre and set them from there.

Timing we are not sure how to do.

Carbs. We havent touched those.

There are 2 silver dome things on the top of the engine next to the air intake and they both have black knobs you undo and it has a dip stick type thing inside. they were empty of oil so we filled them up. dont know if they are the carbs.

[thermidorthelobster]

There are 2 silver dome things on the top of the engine next to the air intake and they both have black knobs you undo and it has a dip stick type thing inside. they were empty of oil so we filled them up. dont know if they are the carbs.

They'll be the carbs.  The bit you're looking at is the oil damper chamber which damps the needle.  You'll probably have a bit of vac hose going to the top of each chamber - this is a system which sucks the needle and piston out of the way of the airflow when you're running on LPG.  Running on LPG for a long time will suck all the oil out of the damper, leading to problems running on Unleaded, so you were right to fill them up (pump them a few times to make sure you have hydraulic pressure, too) but this shouldn't affect running on LPG.

Can you smell LPG when turning over?  Are you sure you have LPG in the tanks?  (Don't go by the dashboard, as they're always inaccurate.)  Can you hear the solenoids on the tanks pinging when you initially turn the ignition on, to signify that the valves on the tanks have opened?  Also check the vacuum hoses to see if anything has become disconnected;  some of the LPG paraphernalia will depend on that.

I'd suggest you stick some petrol in the tanks (even if they're leaking) and try running on Unleaded.  If it runs fine then the problem is down to the LPG system, or possibly the timing.  If it doesn't, then you have ruled out one problem.

So do you have a good strong spark from the plugs (earthed to the block) when turning over?

[muddyjames]

Quote and my answers in together.

They'll be the carbs.  The bit you're looking at is the oil damper chamber which damps the needle.  You'll probably have a bit of vac hose going to the top of each chamber - this is a system which sucks the needle and piston out of the way of the airflow when you're running on LPG.  Running on LPG for a long time will suck all the oil out of the damper, leading to problems running on Unleaded, so you were right to fill them up (pump them a few times to make sure you have hydraulic pressure, too) but this shouldn't affect running on LPG.

It did require some effort to push the tops back on again once we filled them up with oil.

Can you smell LPG when turning over? Yes we can smell gas and also we took off the pipe from the air filter box and we saw gas coming out. It was cold out side and in torch light the light went hazey as the gas came through. Can you hear the solenoids on the tanks pinging when you initially turn the ignition on, to signify that the valves on the tanks have opened?  Also check the vacuum hoses to see if anything has become disconnected;  some of the LPG paraphernalia will depend on that.

We cant see any disconnected hoses. I wouldnt know what the sound of a solonoids pinging would sound like but as there is always gas coming through I would guess they are.

I'd suggest you stick some petrol in the tanks (even if they're leaking) and try running on Unleaded.  If it runs fine then the problem is down to the LPG system, or possibly the timing.  If it doesn't, then you have ruled out one problem.

We were thinking of taking the hose off the tank and sticking it straight into a jerry can and try it.

So do you have a good strong spark from the plugs (earthed to the block) when turning over?

We have a spark when earthed to the block. I don't know what a strong spark looks like but there was certainly a spark jumping accross the plug.

[MuddyMike]

How old is theLPG conversion? I ask because eventually the vaporiser needs cleaning out and posibly a new diaphram fitting.

Mike

[muddyjames]

my mate bought the landy about a year ago and I think he bought it just after the previous owner had just rebuilt the landy so I am guessing 12 months to 18 months.