Forester Turbo on gas hesitating

[cello297]

I have a 2000(V) Subaru Forester S Turbo which I had converted to run on LPG in '08. The car had a slight hesitation at the time on petrol, which seemed to disappear when converted. Since then it has returned and become worse. It is slight on petrol and more noticeable on gas, to the extent that it is impossible to hold a steady speed, forever surging and dying. Twice recently the car has died and been difficult to re-start, once when cold, hence on petrol and once on gas.

Can anyone advise? I'm reaching the stage that I will have to sell a car that otherwise I love to bits.

The car: Subaru Forester S Turbo, registered 1 January 2000
LPG system: STAKO, fitted in '08 (certified)

[fatjon]

A couple of suggestions.

1, when the car dies get out quickly and check the temperature of the LPG vaporiser. If it is frozen solid there is your answer. No end of installers are useless at piping them in correctly and they don't get enough hot water flow. Seen two recently piped in series with the heater. Turn off the heater and the water flow stops on many vehicles which have a solenoid in the heater circuit.

2, my explorer was terrible on gas until I put a new set of plugs in it. There was nothing apparent wrong with the old ones, they looked like they had been in for no more than a couple of hundred miles but replacement cured all the kangaroo hops and spitting back totally.

3, check the LPG filters, they do have a limited life and clog up far quicker than petrol filters.

[stevieturbo]

The fact the problem is there on petrol means its not gas related.


I assume you've done the blatantly obvious things like replace plugs, check ignition system....or maybe even leave it to a mechanic ?

Could be a multitude of things...airflow meter or something. A decent mechanic should be able to diagnose it.

[cello297]

Thanks both. I have tried two freelance mechanics, one of whom fitted the system - or his company did - and the Subaru dealer. The dealer changed something in the ECU, which did nothing for the car, just empied my wallet and said that it must be a gas problem and that he would not touch. Subaru Customer Services were equally unhelpful, though polite about it. The gas man changed a solenoid, following which it changed to and from gas with less lag, but no change to the hesitation/missing + surge.

What does a vapouriser look like?

Will try the rest. I have a problem finding a decent mechanic who admits to having any knowledge of gas systems. The guy I usually use, who is generally very good and utterly reliable, simply switches off the gas to work on the car, as he says he doesn't know about it.

[stevieturbo]

cello297 said:

Thanks both. I have tried two freelance mechanics, one of whom fitted the system - or his company did - and the Subaru dealer. The dealer changed something in the ECU, which did nothing for the car, just empied my wallet and said that it must be a gas problem and that he would not touch. Subaru Customer Services were equally unhelpful, though polite about it. The gas man changed a solenoid, following which it changed to and from gas with less lag, but no change to the hesitation/missing + surge.

What does a vapouriser look like?

Will try the rest. I have a problem finding a decent mechanic who admits to having any knowledge of gas systems. The guy I usually use, who is generally very good and utterly reliable, simply switches off the gas to work on the car, as he says he doesn't know about it.

Given you have alrady said the problem is there on both petrol and gas....you dont need a gas mechanic, you just need a mechanic with a brain.

And as for the Subaru dealer saying they replaced something in the ecu.....if thats true, Im guessing they are either electronic genius's, or talking through their arse in order to charge you money when they havent a notion what they are doing.

Where in the country are you based ?

As much as its full of sh**....register over on scoobynet and ask for reccomendations of garages in your area where the mechanics have a brain. At least you should get a postivie response from that. I'd be wary about asking actual technical advice on it...as for every one person who does know something, there are about 500 who know sweet fa and just spout crap.


Either that or ask on http://bbs.22b.com/cgi-bin/ultimatebb.cgi
You will get sensible responses there.

Edited by stevieturbo on Tuesday 27th April 22:47

[cello297]

Thanks Stevie, Based in Essex, near Saffron Walden. Welsh's is the local money taker in the area.
I will try Scoobie's

[dern]

cello297 said:

It is slight on petrol and more noticeable on gas, to the extent that it is impossible to hold a steady speed, forever surging and dying. Twice recently the car has died and been difficult to re-start, once when cold, hence on petrol and once on gas.

I had the surging problem on my impreza although I didn't have the starting issues... anyway, this will take you ten minutes to try so it might be worth a go. Take the boost control solenoid off and clean it with carb cleaner and stick it back on. Mine started to stick and started to cause all sorts of weird surging issues.

[cello297]

Discovered that when Subaru say that it should run on 98 octane, it really means it! Running well on petrol now and I have a red face, having been too tight to pay the extra!

Still not doing the business on gas.

I doubt that I have fixed the cutting out, though I won't know 'till next time!

Thanks for all your ideas. If anyone out there who knows specifically about LPG converted cars, I'd love to hear.

[stevieturbo]

It will run fine on normal unleaded.

Just noticed in your post thats its a MY2000.

Airflow meter failure on those years are very very common. Get it looked at ASAP, or there is a high chance of it blowing up.