Autosleeper automatic lpg struggling on inclines

[Sir Brixalot]

Hi

Headed north on the m11 today. To start off van was fine, then on prolonged slight inclines began to struggle, down as low as 45mph and even on straights struggled to hit 60. On way back van was mainly back to normal and held speed on incline (with one brief struggle). I was running on gas and the engine is a 1. 9dg, recon. I did notice that the engine sound had a deeper more bass note on the slopes. Has anyone had similar problems? Thanks a lot

E D I T. When I checked the battery today the alternator reading only just scraped into the OK area on the meter - would that make any difference to mph uphill?

[ghost123uk]

E D I T. When I checked the battery today the alternator reading only just scraped into the OK area on the meter - would that make any difference to mph uphill?

No, it won't make any difference, but might need looking at sooner rather than later, before you get stuck with a flat battery. Measure the actual voltage on the main battery whilst the engine is running (let it run for a few minutes before measuring) and "we" will let you know what to do after seeing what reading you get. (Might be needing a £15 voltage reg / brush pack on the alternator = 15 minute job )

Re your main problem, you forgot to say if it does it on Petrol as well ?

If it is OK on Petrol then the only sensible course of action is to get a competent LPG installer to look at it. Do you know where it was done ? (Gasure perhaps ?). It is not recommended for your average home mechanic to mess with gas settings as you can easily do much more harm than good !

[fairwynds]

Are you aware of the adjustable 'powervalve' (if fitted) in the gas line from your vapouriser to your carburetter? Could this have been tampered/knocked/inadvertently twiddled? If you find it (mine a knurled wheel about 1 inch diameter), mark it with permanent pen so you can see how far you turn it. Mine is: turn clockwise to restrict flow (ie more economy but LESS power) and anticlockwise to increase flow (more power but less economy). Run van up to temp, then a quarter turn anticlockwise to see if your problem gets better. Jot down on notepaper what youve done. If not, another quarter turn and so on, up to a full turn. If no improvement, turn it back to the ORIGNAL position (see why you marked it and recorded what youve been doing?!). You could try turning the other way but its unlikely that you are set WAY too high (and you would likely smell the unburnt LPG at standstill).
The vapouriser itself will have a CO adjuster on it, but that will need checking at a garage with an exhaust gas analyser.
Obviously you will have already checked the condition and tightness of your spark plugs?!
And your brakes are not binding are they? (Smells / wheel hot after a decent run/ lots of brake dust on fronts / van wont roll easily on a slight incline?)
Good luck...

[ghost123uk]

As above ^^^ but take care not to get it too lean. The hotter gasses from LPG can quickly damage exhaust valves and you cannot use the old skool method of looking at the plug colour to determine mixture.

Please excuse my "hip hop" spelling of School

[fairwynds]

As above ^^^ but take care not to get it too lean. The hotter gasses from LPG can quickly damage exhaust valves and you cannot use the old skool method of looking at the plug colour to determine mixture.

Please excuse my "hip hop" spelling of School

oops, my omission, and bliddy important too!

[Sir Brixalot]

Thanks, had the lpg serviced at LPG specialist and recently been with elite for other work and I think the checked the mix. I will try adjusting LPG mix, it sounds like a good idea. Still not running properly on petrol beacause last owner stuck mastic all over the place instead of a gasket and the carb keeps getting blocked - need to save up to get a refurbished carb. Lastly the voltage is about 13.5 when running - is this OK? I really appreciate your helpful and detailed advice.

[fairwynds]

Thanks, had the lpg serviced at LPG specialist and recently been with elite for other work and I think the checked the mix. I will try adjusting LPG mix, it sounds like a good idea. Still not running properly on petrol beacause last owner stuck mastic all over the place instead of a gasket and the carb keeps getting blocked - need to save up to get a refurbished carb. Lastly the voltage is about 13.5 when running - is this OK? I really appreciate your helpful and detailed advice.

That voltage at battery is fine imho (any rise or fall when engine revved?) SOmeone qualified will respond no doubt to confirm.
Definately get carb sorted, that may be your issue, air being sucked in where is not wanted and making the combustion mix too lean. And as stated above, lean is BAD and you should sort that asap due to potential for valve damage

[ghost123uk]

Yep, that battery voltage is OK, it's at the low side of the range, but not outside the range.

I would get Elite to check the mixture, they might even do it as a favour if they have recently worked on it. As above ^^^ check for any gasket leaks around the carb base, manifold to head joins (rare) and also the brake servo hose (on top of the left side of the left inlet manifold).