range rover lack of popwer

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Mon 30 Jul 2001 21:07
range rover lack of popwer - David hendry
Range rover 1988 se vogue automatic 112000miles . lpg conversion 1999 @ 95000. Decoke 93000

I recently purchased car It runs very smoothly always starts first time but lacks acceleration and pulling power

Took car to range rover specialist who did compression test which he said showed all cylinders to be 60 PSI and should be 160PSI. CO2 test okay.
Conclusion that valve timing out likely that timing chain had jumped a cog. Would replace chain £150 - £250 and re-time

I think I am being had . Could the valve timing be so far out to reduce compression to 60 psi and yet car still start and run okay. fuel economy is 15mpg on lpg which is about right. runs runs equally well on petrol or gas

Your comments would be appreciated

David
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Mon 30 Jul 2001 21:52
LPG Tune-up needed! - David Lacey
I would suggest, from experience, that the LPG system is not up to scratch.
Find a trustworthy LPG specialist and get him to give it the once-over.
It may only require a simple re-tune.
I'm fairly sure it will be fine afterwards

Rgds
David
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Mon 30 Jul 2001 22:28
Re: range rover lack of popwer - Tim Winfield
Hi David, 60 psi does sound very,very low. Compression checks can be a little misleading by virtue of the way they are carried out. If you use a screw-in type it is difficult to keep all the readings the same, unless you just turn the engine over for several revs and get a highest figure. It can be advantageous to use a cheap plastic hand-held meter and try releasing it after 1 or 2 revs to see how FAST the pressure is building up.
I think Dave Lacey may be closer to the mark when he suggests an LPG tune-up. If your metering valve(in the main gas feed to the inlet tract) is not a stepper valve, but a screw valve, it could have lost it's setting or even been moved by some-one who is jealous of your Range-Rover's frugal consumption.
GOOD LUCK. TIM and SARAH (who is the RR expert out of the two of us)!!
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Mon 30 Jul 2001 22:29
Re: LPG Tune-up needed! - Guy Lacey
Dave!

Fully rested from the "inflatable sheep" weekend in Blackpool?

I agree. My lpg conversion has required a few tweaks here and there as the system has bedded in. I have managed to reduce the lpg flow at top end without loss of power but suggest the Landy in question requires the regulator screw turned out a few notches to allow more fuel at top end.

A *good* converter should take the mota out and warm it up to normal op temps then floor it in 2nd or 3rd. It should not lose power at top end. If it does it simply means the regulator screw is such that the lpg supply cannot keep up with engine revs.

Simple way to check. Wind the screw out. Whazz the car up to the red line. If it feels as though the rev limiter is coming on b4 it should then you need to wind it out more. Likewise, if it feels OK then wind it in. When it feels tight at top-end wind it *out* a quarter of a turn and leave until 2-3,000 miles l8r.

A friend of mine with a BMW 750iL LPG has got 50miles more out a tank of LPG by purely one quarter of a turn on the regulator screw.
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