[Haydenp38]

I bought my second Range Rover 1994 P38 4.0 V8 Romano LPG about 4 months ago and have carried out alot of servicing/replacment parts. The problem I am having is that the car wont idle on petrol it was ok when I firts got the car, but idle's fine on lpg, I cant remember when this actually started or what I had change or replaced whe fault started.
Tonight I changed the crankshaft position sensor because my little foxwell said there was a fault.
What I have noticed is that when you are driving at a constant speed and turn the gas off there seams to be a noticable power loss and the mpg becomes poor, could this be injector/pump problem I have already change the
fuel filter
Stepper motor/idle motor
Mass air flow sensor
Temp sensor
Crank position sensor
O2 sensors
Cats
Air filter
Oil filter
HT leads
Spark plugs
Oil
Battery
any thoughts?

Thanks Hayden

 

[Saint.V8]

Dirty Injectors???

Running on LPG constantly tends to gum up the injectors...maybe a spot of injector cleaner wouldn't hurt.....

If it runs fine on LPG, then that will rule out the ignition system, CPS, O2's etc as these are common to both systems...

The only additional would be a weak fuel pump causing lack of fuel pressure or dirty injectors.

I assume your LPG system is multipoint...

 

[Haydenp38]

Hi thanks for quick reply, I will try some injector cleaner tomorrow do you reccomend any particular brand.
The LPG system is single point but i am going to change for multi point in near future.
Thanks Hayden

 

[Saint.V8]

If it is single point, check your intake ducting for splits or loose joints....

Single Point LPG systems don't usually use the MAF data to run, so you can pretty much have no intake ducting up to the LPG ring and it may run fine...but will not run well if at all on petrol without an airtight ducting in place....

As for Injector cleaner...go for a good known brand like the one I can't remember beginning with R

 

[rewmer]

I wager its nothing more than the LPG system needing a tune. Yes I know it runs fine on lpg but the short term trims will allow for the error in carburation. Eventually you will get an engine managment light and the code "trim level maximum" or similar. Answer ? Get the ECU adaptions reset and get the gas system tuned.

 

[rewmer]

Cock. Missed the bit about single point. Ignore all Ive just said and get a fuel pressure check, maybe pump or regulator.

 

[eightinavee]

Cock. Missed the bit about single point. Ignore all Ive just said and get a fuel pressure check, maybe pump or regulator.

Nah, I think you had it first time - the long term trims of the poor old Gems ecu will be sooo far away it simply wont have a chance.
Bin the forklift system,fit a multipoint system and it might work.(But only if someone goes to the trouble of tuning it properly)

 

[lowfat]

reset the trims and it will be okay for a time. then need resetting again Ad infinitum

 

[Haydenp38]

Hi guys thanks for the info, tried the injector cleaner passed trough two bottles real tough stuff trade only stuff. The first treatment had an immediate effect the car idled well when it was cold and managed a short journey on petrol stop starting with no problems, but when it got up to temperature it started to cut out at idle again. The only thing i haven't looked at is the knock sensor? could that cause these symptoms, also could one of the sensors i fitted be broken already i fitted cheap O2 sensors and second hand temperature sensor, left battery of over night to reset thing still same problem get to temp wont idle,i just don't know i love my Range Rover,
cheers Hayden

 

[lowfat]

Where are you based? someone might be near with diagnostics

 

[eightinavee]

Hi guys thanks for the info, tried the injector cleaner passed trough two bottles real tough stuff trade only stuff. The first treatment had an immediate effect the car idled well when it was cold and managed a short journey on petrol stop starting with no problems, but when it got up to temperature it started to cut out at idle again. The only thing i haven't looked at is the knock sensor? could that cause these symptoms, also could one of the sensors i fitted be broken already i fitted cheap O2 sensors and second hand temperature sensor, left battery of over night to reset thing still same problem get to temp wont idle,i just don't know i love my Range Rover,
cheers Hayden

Disconnecting the battery will not reset anything - that needs to be done on Testbook or similar.

 

[rewmer]

Cheap O2 sensors ? Asking for trouble... Do some simple tests and get some live data from the O2s with a multimeter to see what's happening. Pouring magic juice in the tank or randomly guessing and swapping out parts is going to cost way more than a good diagnostics session.

 

[Haydenp38]

I live in Ebbw Vale, Gwent, i borrowed a foxwell diagnostic came up with a P0326 knock sensor 1 circuit range performance bank 1 or single sensor. I saw a video on u-tube how to test the voltages so will give it a try, are knock sensors like any other sensor they can break down and fail. Should ask really where are the sensors located, Thanks guys have a happy new year

 

[Saint.V8]

I live in Ebbw Vale, Gwent, i borrowed a foxwell diagnostic came up with a P0326 knock sensor 1 circuit range performance bank 1 or single sensor. I saw a video on u-tube how to test the voltages so will give it a try, are knock sensors like any other sensor they can break down and fail. Should ask really where are the sensors located, Thanks guys have a happy new year

Download RAVE they will tell you where they are located (on the block, near the bottom!!)

Manuals

 

[Haydenp38]

Ebbw Vale Gwent Wales just took a reading from the knock senors from ECM bank/sensor 1 is very much diffrent from bank/sensor 2 bit to much of a coincidence, thats what the foxwell machine said.
Just a little question where are the knock senors back to the rave i think,
happy new year Hayden

 

[Haydenp38]

Hi, bought and fitted a new knock sensor had no effect, so i checked the voltage on my ecu from O2 sensors had about 4.5 volt give or take but not fluctuating, connected a foxwell reader showed one of the O2 sensors at about 1.2v and the other 0.950v up and down. so i fitted some old sensors i had, i had to solider new connectors on to them. tested voltage at ecu it was a little higher 4.7 volts give or take connected foxwell and it read theO2 sensors at about 0.9v with a difference of about 0.10/0.15v with a little movement up and down, with the old sensors i achieved tick over for the first time in ages and i also had power when running on petrol.
I believe the cheap O2 sensors i fitted had a negative effect the old sensors i took off a scrapped car are originals.

questions are how much should you pay for good o2 sensors if you cant afford landrover parts?
should the voltage at the ecu be changing up and down constantly at the ecu, like videos i watched on utube?

many thanks Hayden