Anyone have any hints for LPG tuning

[mikecairns]

Hi, My recently purchased v8 disco is proving to be a difficult truck to tune. I have added photos, in the second the pipe on the right runs from the chamber to air intake, I found this on a forum saying it should be added to help with the air intake, it originally had a rubber stop that was broken, should I block it or keep the air intake on it? I have had the truck tuned, or so I thought at the only Cairns lpg certifier, it ran with no power at all, after looking at the dist cap it looks like the rotor was too advanced or retarded, arc marks on the left of the dizzy and the right of the cap, I adjusted to try and it gained heaps of power. It is a 4.6 block with all the 3.9 stuff on top, should the timing still be 9-10 degrees before t.d.c, or could it be different? If I adjust timing to suit gas it flies, but backfires when decellerating on petrol, if I adjust it to not ping on fuel, it has no power on gas,
Any ideas greatly appreciated, oh and the oil is from a leaking hydraulic steering pump, is it worth trying to fix? Have heard of a gasket replacement and clean, its not the connections.
Mike

[It'sNotWorthComplaining!]

Bend down on your knees and bow your head and wait until Bee-Utey reads this post. He's the LPG Guru:blush:

[mikecairns]

Thanks, I have already seen how good beeutey's posts are, have used it to check the maf has volts all the time, temp sensor and connectors, loom and maybe the right relays:mad: seem to be ok
Appreciate all help

[bee utey]

Hi, My recently purchased v8 disco is proving to be a difficult truck to tune. I have added photos, in the second the pipe on the right runs from the chamber to air intake, I found this on a forum saying it should be added to help with the air intake, it originally had a rubber stop that was broken, should I block it or keep the air intake on it? I have had the truck tuned, or so I thought at the only Cairns lpg certifier, it ran with no power at all, after looking at the dist cap it looks like the rotor was too advanced or retarded, arc marks on the left of the dizzy and the right of the cap, I adjusted to try and it gained heaps of power. It is a 4.6 block with all the 3.9 stuff on top, should the timing still be 9-10 degrees before t.d.c, or could it be different? If I adjust timing to suit gas it flies, but backfires when decellerating on petrol, if I adjust it to not ping on fuel, it has no power on gas,
Any ideas greatly appreciated, oh and the oil is from a leaking hydraulic steering pump, is it worth trying to fix? Have heard of a gasket replacement and clean, its not the connections.
Mike

Hi Mike,

Firstly the engine breather should be reinstated as LR had it, ie the drivers side rocker cover breather to the tee piece and the fitting by the throttle body. People who reconnect the breather elsewhere do so because other cars require it, and make the assumption the LR does too. Well they are wrong, there is no possibility of gas/air fumes being drawn into the crankcase, as would happen with Fords and Holdens. Block/remove all other breather connections.

Secondly, the advance required depends on engine compression ratio and petrol type. If your engine has been modded for higher compression you will need to run premium unleaded or octane booster. There is no point running retarded timing and gas, run whatever is best on gas and make the petrol cope. 8-10 degrees should still be OK with gas.

If you are unable to manage this you perhaps should look at a dual timing amp (I have no experience with them but they make sense):

RPi Engineering - Specialized Rover Engines - faqs (http://www.v8engines.com/faq-a-and-r.htm)

Lastly you can use a wider rotor button if your spark is off the end of the standard button, Bosch part number GB864 (XF Falcon). I've done this a few times with success.


Bend down on your knees and bow your head and wait until Bee-Utey reads this post. He's the LPG Guru:blush:


Snortle.:cool:

[mikecairns]

Thanks bee-utey, replaced the rotor button and has helped getting it tuned. The extra air intake tube I blocked and it also helps. When I bought the car I believe the afm was disconnected, opening this other air flow helped the car run smoother when it was 'sick'. Its needed leads, dist cap and rotor plus wiring cleaned. Now I've fixed all the ignition bits, it idles when stopped at 6-700 rpm and when slowing about 1100 rpm, with the extra air it idled when slowing at about 1500-2k rpm. To get the power it would appear timing for gas is way off petrol and I always run premium, cause I love my cars! Thanks for the help,
Mike

[ozscott]

Not everyone needs to go this far but for my 95 D1 I got a Scorcher Ford/Holden homologation dizzy from Performance Igntions with an Australian Bosch HEI module (getting parts or replacement module even from a roadside RACQ patrol is now easy...for way down the track) and their coil to match. I got their leads also...the difference was amazing and their was very little obvously wrong with the Lucas Dizzy, but..its Lucas...and any little bit of wear seemed to throw them out, but some people get lucky with them. The D1 on petrol and LPG runs like never before. I have had this for over a year now and it really is the business.

Cheers