You may have seen my earlier posts regarding an unsolvable cold starting problem in my 97, LPG converted GS300.

The problem is now solved, albeit at the cost of reconditioning the head as two exhaust valves were burnt, at a cost of £2,100.

The car had done almost 100k miles since its conversion, and did not have the "valvesaver" system fitted, but the main caveat when running on lpg is to make sure you do 15% to 20% of your mileage on petrol, which should give the necessary protection to the valves and seats, and save you my 2k bill.

Now that the head has been done the car runs perfectly, and does close to 25mpg on LPG, at a cost of 35 to 40 p per litre, a cost of 7 to 9 p per mile, or the equivalent of 50 to 60 mpg, so if you can avoid the head wear, it is a big money saver, especially if, like me, you do high mileages.

Have you had a flashlube system fitted now?

Daniel.

There have been a number of these cases on Toyota engines. I believe all of them have been without a flashlube.

Had my Mk.2 GS converted a few months ago (must post pics sometime). Got flashlube.

Nope, only got the car a few months ago, didn,t pay much, and relaxed about this big bill, other than that its a fine car. Will look up Flashlube and have it fitted though.

You say running the car on normal petrol every so often, how is this possible. Excuse my ignorance. Do you have like a switch in which you flick so the car starts drawing petrol from the stock tank?

Would you need to reset the Ecu to?

Just curious thats all

yep most just have a switch so u can switch between normal petrol or LPG

Ouch!
I've also just bought a 95 GS300 LPG converted and on the way home today it made a strange "Bang" sound, thought I had run over a big stone at first, but when it did it a few more times usually at 40-50mph, I got a bit worried. It idled terribly as well making me think it was only firing on 4 or 5 cylinder. There also seemed to be a weird 'crackling' sound and a burning smell emanating from the cat when I got home. After reading this post a day or two ago I ran it on optimax for a hundred miles or so the other day.

I'm fearing the worst - any pointers??

hi,
it might have been a back fire in ther air box,mines does this now and then .Check tht the blow off flaps arent bent if they r just bend them back .Also on mine if it back fires it normally blows the air box and air filter adrift check this for air leaks
hope this helps Andy

Hi,

Can you explain the nature of your starting problem? I have an LPG converted ls400 that has a starting problem, I wonder if its the same thing. After leaving it overnight, I turn the key and it fires well, climbs quickly to maybe 1000 rpm, then drops to zero. It tends to do this 2 or 3 times, and then on the 3rd or 4th attempt in quick succession, it climbs to 1000, drops to nearly zero, but just catches itself and climbs to idle at about 600rpm.

Touching the accelerator as I turn the key solves this, but obviously this shouldn't be necessary.

I was wondering if 600rpm was a little slow for a cold idle. Do you think my engine is attempting a 'warm' start, even when its cold? Or do you think it has worn valves like yours? It doesn't have flashlube; I better get that fitted.

Many thanks,

Rob

Hi Rob

It turns out that my car needed a new set of plugs. It didn't help that the air filter was the wrong one for the car and that when the throttle body was bolted back on, their was two bolts missing so that my car still had an air leak (It's getting sorted next week). For your LS, if the spark plugs are easier to access than on mine, have a look at those first.

Good luck!

Thanks genius,

I've followed some advice form somewhere on here, suggesting turning the key to '0n' for 10 seconds before turing to 'start', and this does seem to work, I can hear the pump run. I wonder if, because the car always shuts down when running on gas, the solenoid to turn off the petrol is off. When you turn it on again, you have to give the LPG conversion's 'brain' a chance to open the petrol tap again, and also give the petrol a chance to get back to the engine before firing it up. Just a guess


Rob

aaah that would seem logical. I tend to do that anyway as part of putting on seatbelt/sorting out radio/phone etc. routine. I'll try starting straight away this morning and see if I get a problem. (apart from being late for work )

Cheers
Neil

Update from this morning...

Started fine, but then I realised that the engine is idling far too high (it is being sorted for the air leak next week) so it was a pointless exercise, but then I'm not a morning person

Sadly though, i had a brief encounter this evening with a young lady in a Citroen AX who was driving a little too fast down a very narrow country lane. Her car was wrecked - I have a dented (well flared) wing, bumper and a smashed headlight. The irony is I had just ordered a new bulb for the o/s headlight as well

I've been running on LPG for a couple of years now and have just experienced overheating and loss of water attributed to a head gasket failure. Has anyone any experience of this? Is it normally just that or is there likely to be damage to the head, for example distorted or cracked.

Hi I have has the same problem with my 2002 model IS 200 SE. Ran pretty well for the first year, though there were problems with stalling when engine cold. Finally diagnosed 2 years and 50,000 after LPG conversion. £2500 repair job. New valves hardened seats & still not sorted. phil E.

Problems stalling when cold sounds like underfuelling, mine did that until I upped the fuelling a bit (got the cable to program the Romano ECU). As for valve wear, did you have a Flashlube kit fitted? This is recommended for all Toyota engines.

Just taken the IS200 in again to the LPG garage, and there is valve wear again, one year on from strengthened valve seats and new valves. They are going to repair the damage and fit a flash lube kit. I would be interested to hear of anyone running an IS200 long term on LPG, and know the secret of their success. Also I have heard that if you run 20% of the time on Petrol that this is helpful but surely if there is a problem, then that is only going to delay the problem by 20%, or am I missing something?