Thread: P38 on gas

I have an EMER sequential system fitted and besides a few niggling issues, I am really happy with it. - fitted by Carb and Gas in Brisbane. I regularly get 18l/100km on the freeway at steady 100km/hr and 20l/100km with a suburban highway mix.

The car runs very smoothly on LPG and has no perceptible power difference under normal operation.
However when entering the freeway, and using full throttle and sport setting, the gas system cant keep up with fuel demand and changes to petrol at about 3500RPM.
Also there is a rpm drop every now and then on the cutover to gas at idle. This occurs only if I let the car idle after start and remain idling until cutover to LPG.

It does throw the following codes when on LPG -:

P0175 = ADDITIVE ADAPTIVE MIXTURE CORRECTION TRA BANK 2 DRIVE CYCLE B, WHICH HAS OCCURED 99 TIMES (SIGNAL TOO HIGH, THE FAULT IS CURRENTLY PRESENT, , THE FAULT HAS BEEN DETERMINED AS PERSISTENTLY PRESENT).
P1000 = ADDITIVE ADAPTIVE MIXTURE CORRECTION TRA BANK 1 DRIVE CYCLE B, WHICH HAS OCCURED 99 TIMES
(SIGNAL TOO HIGH, THE FAULT IS CURRENTLY NOT PRESENT, THE FAULT HAS BEEN DETERMINED AS PERSISTENTLY PRESENT).

These don't occur when on petrol. There is no roughness at idle and they are only a indication that the O2 sensors are detecting a rich condition at idle. The short term fuel trims adjust rapidly and command lean immediately. The O2 sensors also rapidly respond and then cycle normally low to high rapidly as they do when on petrol. It all works as it should.

For information( BOSCH EMS): TRA - Time Relative Adaptation: additive learning correction coefficient per time unit ; a fuel injection adaptation method used to compensate for engine/ sensor changes at idle, which are short term & small affecting the AFR. (The threshold for (DTC 175/171/174) is; TRA additive >±0.452ms)

If I clear these codes then drive on petrol for several hours these codes do not reappear - so all my sensors are working correctly.

Not big issues - the EMS adapts quickly - but still issues

Hi All P38 Gas Converted Drivers,

I own a 2001 HSE 4.6 and am keen to run it on gas. I have a Stage One 3.9 that has been running on gas for about 6 years and I have been very happy with it. Of course it is a carburettor with out any of the electronics found on my HSE.

I would really like to know if any one in Perth has been happy with the conversion of their P38 to gas and could maybe PM me a name of a company that are competent in the conversion of the Rangie. I have owned the P38 for about 7 years now and love the vehicle but the price of petrol is killing some of the fun.

Look forward to some feedback from a few happy West Oz Gassed P38 drivers.

Regards Warrick.

I am looking at removing LPG altogether from my 1997 P38. It keeps backfiring all the time, I have had it serviced recently and the previous owner also had it serviced just prior to me buying the car last year.
The last backfire blew up the new airfilter and the air intake pipe, don't know right now the correct term sorry. this car is my daily driver for work and I love the car but I can't afford problems.
I am looking at buying a P38 HSE for my wife and I would prefer it didn't have LPG or if it did it was dedicated LPG and not dual fuel.
I have been searching all night for a really good Range Rover gas expert in Perth that I could take my car to so I can get this sorted once and for all.

Robbo:
if it was me mate... I'd ditch the Current "Mixer" Type LPG Setup and upgrade to a Sequential Injection System....

Kit from the UK or Similar for 8 Cylinder Car would be around ~$600 from Ebay... You have the Tank etc. in the back... and Installer would probably charge around $700-1000 to fit the Under bonnet Kit (Perhaps even less)

So for around $1300-1500 you will have the benefits of an Injected LPG Setup (No Backfire, Improved Gas Economy, Better Power) with no dramas at all from the older Mixer Setup.

I've done the same thing to 3 x P38's I've bought 2nd hand which were "stuffed" by Dodgy Mixer LPG and it's been awesome...

(I do the Manifold etc. work myself so it's only costing me the $600 from the UK Each Time)

Originally Posted by RobboLFC

I am looking at removing LPG altogether from my 1997 P38. It keeps backfiring all the time, I have had it serviced recently and the previous owner also had it serviced just prior to me buying the car last year.
The last backfire blew up the new airfilter and the air intake pipe, don't know right now the correct term sorry. this car is my daily driver for work and I love the car but I can't afford problems.
I am looking at buying a P38 HSE for my wife and I would prefer it didn't have LPG or if it did it was dedicated LPG and not dual fuel.
I have been searching all night for a really good Range Rover gas expert in Perth that I could take my car to so I can get this sorted once and for all.

The number one most important thing to do with a simple gas system on a P38 is to set the spark plug gaps to 0.6mm/0.024". The best LPG plugs I have found are Bosch part number WR7KI33S which are specialist LPG plugs and will need to be ordered by your parts shop from Bosch. They work extremely well. Under no account do you run bigger gaps on a LPG dual fuel P38 unless you convert to LPG vapour injection. Vapour injection is the ducks guts on the P38. It works better than LPG-only dedicated systems and doubles your fuel range.

If it still backfires on LPG after fitting these plugs you may need new coil packs.

The next big thing on P38's is to use a metal air cleaner assembly off an early D1. The MAF will clip straight in. Use a heavier rubber air hose off something like a VN Commodore or silicone hose from a speed shop.

Originally Posted by BusinessConnected

Robbo:
if it was me mate... I'd ditch the Current "Mixer" Type LPG Setup and upgrade to a Sequential Injection System....

Kit from the UK or Similar for 8 Cylinder Car would be around ~$600 from Ebay... You have the Tank etc. in the back... and Installer would probably charge around $700-1000 to fit the Under bonnet Kit (Perhaps even less)

So for around $1300-1500 you will have the benefits of an Injected LPG Setup (No Backfire, Improved Gas Economy, Better Power) with no dramas at all from the older Mixer Setup.

I've done the same thing to 3 x P38's I've bought 2nd hand which were "stuffed" by Dodgy Mixer LPG and it's been awesome...

(I do the Manifold etc. work myself so it's only costing me the $600 from the UK Each Time)

Digging out an old thread here, but can you tell me where and what system you have been purchasing?

I too, am very interested in this. I have completed abondoned by single point system and never ever turn it on. I would like to get a second inlet manifold and a injection kit like you mention. Then I could fit the injectors and drop into a shop for the rest to hook up.

Yes i have access to a few different sets of gas system and tanks, if i keep the p38 gas would be a nice option.