newbie! P38 cutting out when warm

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Weirdly - I have a Freelander that is LPG converted and has just developed exactly the same problem - apart from I can run mine on petrol with no problem but on lpg - and whilst at idle the engine stalls and will not start again. Also when it is running fine - I will turn off the engine and if I go back before it has cooled down it just wont start on petrol or lpg. Go back when cold and starts first turn of the key - This seems too much of a coincidence bearing in mind both these vehicles are lpg converted -
 
and mine is an almost new engine with less than 8k on the clock....

So then - what sensor would impact lpg running but not petrol? and stop it starting again until its cold?
 
hmmm - Dont think so - since problem does not materialise if started and kept to petrol. Plus not slurping more juice than normal? On LPG problem only happens sometimes - might be after stopping at shop or might be when pulled up at junction, but either way, car wont start again on gas or petrol until it is cold.
 
I've just took my mass air flow sensor off and there is a little hole worn/blown into it. I still havent fixed mine. Mine has got a switch on the dash to switch it from petrol to gas, but don't know if it swaps over automatically when warm or not, guess not. My mate reckons the valve seats might be coked up, stopping it from running on gas? Still need to put fresh petrol in it though.
 
for the purpose of the experiment just bung the hole for now, it shouldnt switch if its on petrol but you can set it in the software to do this if it has a temp sender on the vapouriser or its connected to the coolant temp sensor(something i would like to look into on mine)

if it runs on petrol then it should run on gas!
 
Just bought a mas off ebay, might bung the old one up and try it tomorrow. Im hoping I've just got crap petrol in there, as it's been stood for 3 years and I havent put any petrol in it yet. Going to have to put some in this weekend. Had a Range Rover sport come in for a service today, and it's making me want to get mine done now.
 
mattfletcher said:
I've just took my mass air flow sensor off and there is a little hole worn/blown into it. I still havent fixed mine. Mine has got a switch on the dash to switch it from petrol to gas, but don't know if it swaps over automatically when warm or not, guess not. My mate reckons the valve seats might be coked up, stopping it from running on gas? Still need to put fresh petrol in it though.
Click to expand...
is it a case the engine has been backfiring on gas to cause the damage to the air flow sensor?
 
Looking at it actually, it looks like it is where someone has tried to butcher a sensor in it, I guess for the gas. The sensor is now opposite the hole and on the different side of the air flow sensor. If you know what I mean. I had it running the other week and it was flaming out the inlet after it had popped the air filter pipe off, that was on gas. My mate reckons constantly running them on gas does let the valve seats burn properly resulting in them coking up. But I dont know.
 
My mate come round yesterday afternoon, and plugged his scanner in, 5 faults found to start with.
Mass air flow low voltage output
Mass air flow high voltage output
Coolant temp sensor high voltage output
Coolant temp sensor low voltage output
Camshaft position sensor.

Cleared the faults and the one that kept coming back was the camshaft sensor. Which would be right as I had previously unplugged the coolant temp sensor and mass airflow sensor to try and pinpoint the fault.
We then unplugged the camshaft sensor and low and behold the engine was behaving exactly the same as it was with it plugged in, and the scanner still reading the same fault, so hopefully new camshaft sensor is going to solve my problems.

Also read the ABS system and came up with a fault. "all wheels moving at more than 7k.p.h." or something along those lines? Maybe because its been jacked up and someones spun the wheels seperatley?

My next problem is gearbox fault showing up on the dash. My mates scanner wont read the transmission, so wondering if there is a trick to read the gearbox faults or to clear them, without actually going to get raped by the dealer? I'm going to change the oil and filter in the box at one point, which Im hoping is going to fix the unknown fault?
 
mattfletcher said:
Hi, after several years of dreaming about v8 range rovers, Ive finally took the plunge and bought one. Only trouble is, it's got an issue.
Right Im sorry and ashamed that my first post on here is a trouble shooter one, and hopefully as time goes on, I will get myself and my RR, known and involved in this forum.
But for now I'm stuck with this problem, and due to me being new to the RR scene, thought Id post this up here to see if any of the knowledgeable members on here could help me out.
Right down to the nitty gritty; The RR is a 1995 p38 4.0se on LPG. What the problem is, is that it starts up sweet, runs sweet, no smoke no noises or rattles etc, but as it starts to warm up after about 10 minutes it cuts out and wont start until you've left it to cool down abit. The top Radiator hose is warm, the header tank gets warm (although the level in the tank does rise every now and again as if there's an air lock). The viscous fan seems to be spinning fine, there's no water mixing with the oil, or oil mixing with the coolant. The temperature gauge was reading a third of the way when it cut out, so wasn't overhaeting according to that. I'm thinking maybe coolant temp sensor? but thought I'd check on here first to see if anyone has had the same problem.
Many thanks in advance for any advice or help. Matt
Click to expand...


I have the same problem mine is a 2000 4.6
 
First thing above everything else is put a new battery on it (the biggest that will fit) otherwise you'll be chasing random faults forever.
Also, don't put too much trust in diagnostics done with non specific LR scanner. You need a nanocom on it really.
 
But you said that the battery was dead. If its been dead for a year, its likely that its toast.
P38's need a tip top battery.
If you're planning on keeping it a while, I'd seriously consider buying a nanocom, worth their weight in gold!
 
My 4.6 runs rough as old boots when the plugs go bad. About 18 months. Depending on mileage. LPG kills the plugs. tried the awesome super duper Platinum LPG plugs at 60 for a set. no difference. a set of BPR6ES for £18 and it goes like a scalded cat again
 
Sounds like the problem I had with my crankshaft sensor. Would run until warm then the engine would 'hiccup' and die. If you happened to have the throttle up a bit when the hiccup happened it would power through and keep running. If it died it then wouldn't start again until it cooled down.

Changing the crankshaft sensor fixed it immediately.
 
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