The V8 Owners Forum -

when i put my foot down on lpg it feels like it's running out of fuel , it's fine just crusing around it's only when i give some up through the gears ..
i have one of those OVML vaporisers and a ring mixer in front of the AFM ( flapper )
any ideas welcome please ...ps: it fine when i switch to petrol and it settles down again one i stop giving it some

Keith,

Just thinking of what you said about it pinking on gas, could it be it's just not getting enough gas and is in effect running too lean.

Can you richen the mixture on LPG?

Kevin.

This might be a right can of worms. My van is the same, albeit not so bad. Note that I have an Innovate LC-1 so I can see exactly what is going on.

The basic issue that I have is that to get the idle mixture somewhere near right, I had to plug about 1/2 of the holes in the mixer ring and have the idle screw right in. The consequence is that at full throttle, there isn't enough 'such' on the vapouriser to feed in enough gas and it runs lean.

I've decided that it's a good compromise because idle & cruise are OK, it's just that full throttle is too lean, so I switch to petrol for overtaking.

Chris.

Hi Kevin & Chris , yes i can richen the mixture , you know i completey forgot about that pinking ..i was also reading the post about dissy bits , i don't think i'm getting anywhere near full advance at revs ??
anyway lpg , i have one of those Lambda controlled "power valves" and i have the red/green lights on the dash that run red for rich and green for lean ..
accoring to the instructions it should alternate between red and green when driving and hold red under acceleration
this one http://www.lpg-kits.com/lambda.htm

the strange thing is it seemed to be ok when i had the basic vaporiser and since i changed to the OMVL thingy
i will try and richen the mixture and see what happens ..
oh the other thing .. i put my gunson gas tester and it's running around 2% on gas and petrol on tickover ?? too lean ?

Try adjusting the co to about 1.5%, using the main mixture flow screw in the feed line from the vapouriser to the mixer, with the engine sitting at 3000 rpm when stationary. Then adjust the idle co to 2.5% using the idle mixture screw on the vapouriser itself, then re-check at 3000, repeating the process as required. Note that a small adjustment on the main screw has a marked effect at idle, but the idle screw only has a small effect on the main, hence the need to re-check.

thankyou badger , i'll give that a try ...i have one of those lambda controlled main screw thingys
and a OMVL vaporiser
which of the 2 screws is it on the vap ?

I was dreading you asking that! In all honesty, I can't remember it's so long since I installed one of those (it all seems to be SGI work, this last 3 years or so) but I think it's the one with the spring under the head of the screw.
Might also be worth removing the lambda thingy and sticking a manual valve in - just to prove the vapouriser can flow enough gas.... there are different versions of that vap. and it's possible you've been supplied with one that isn't rated sufficiently.

Hi Badger , i have got a manual valve thingy sdo i'll try that ...and really i'm not sure about the spec of the vaporiser
it's a R90/E and a few more numbers on it too

this is a picture of the actual one i have , i got it off ebay a little while ago

Hex screw on the far left of picture (with the lock-wire holes) is the idle mixture. The R90 comes in 2 versions - standard and high flow. Testing with a manual valve will confirm whether it's a vapouriser issue or not. Try talking to FES Autogas (0845 230 1819) on Monday to determine from the part numbers whether yours is high flow or not.

Hi , i checked and it is the high power version i have ...and it's still pissing about ..
it just won't rev and when i put my foot down it kangaroos down the road ..
it's really beginning to piss me off ...i have tried everything ??

is there a better vaporiser that i can get ...thsi poxy 2 stage thing is too much hastle ...it's like brand new but just can't seem to cope with demand

You might have a mismatch between the mixer & vapouriser.

I had precisely that on my van when I fitted a different mixer. I ended up plugging 50% of the holes in the mixer to get the mixture somewhere near. The adjustment screws on the vapouriser needed more turns.

I had an on-board lambda sensor so I could at least see what the mixture was up to....

Chris.

Hi chris , i have one of those lamada control power valve thingys so i can see by the red & green lights if it's running ok ..and it seems to be ok as far as that is concerned ..
i have a round mixer's like this one :http://www.stargasphil.com/stargas/images/mixer_new.gif

mounted in front of the AFM ..is it possible it's over fueling as opposed to under ?
would that cause it to kangaroo ?

ps:
i tried to get it too rev out today going alone my local dual carrigeway and it was like it wouldn't kick the second stage in , then it did a great big backfire no damage done as my blowoff ring thingy saved it ....

i'm beginning to wish stayed with the old STARGAS vaporiser and flat plate mixer ..it seemed ok on those

I fitted one like that to the plenum (to replace the one on the air filter side of the AFM which was a major restriction), and used it with a vapouriser just like this:
http://cgi.ebay.co.uk/OMVL-LPG-Reducer_ ... 240%3A1318

I found it ran very very rich, hence I had to block up about 50% of the holes to get it somewhere near.

I don't know if those red / green light thingies are very good, I used an Innovate LM1 which made it pretty obvious what was going on.

Have you got an AFM?

Chris.

thats exacty the vaporiser i'm using , and i checked it is the high power version too
i friend of mine has leant me an LM1 but i havn't tried it yet

Get that LM1 installed and see what it tells you. I found mine invaluable whilst debugging mine.

Chris.