Son's P38a - She no go

[Armitage_Shanks]

G'Day guys.
I thought I'd sign up because my son purchased a P38a last week. He is very proud of his new toy, but it died yesterday. So I'm going to need to have a crash course in P38 RR fault finding.
I'm familiar with a toolkit - I only just did the cam belt on my Toyota 4Runner last weekend, and I'm familiar with the concept of OBDII diagnostics.

A bit of backgound on the vehicle... It's a 4.0ltr, auto, approx 230k on the clock, Sequential Gas Injection system.
The vehicle starts on Petrol, but then dies when it switches to gas. If he switches it to Petrol it will run, but run roughly. It'll only get him moving to about 50Km/hr.
Can anyone give me a list of things to check? I'm going to plug in my OBDII scanner to pull down the codes on the weekend (if I can find the connector).
Sequential Gas Injection I'm not overly familiar with, but I have read some of Bee Utey's posts in the LPG forum about cleaning injectors, which I'll have a go at on the weekend. However, I don't think this problem is confined to the LPG system since the vehicle doesn't run well on Petrol as well.
I'm hoping there'll be OBDII codes which will point to the problem, but is there anything in particular that I should be looking?
Thanks.

[Keithy P38]

G'day and welcome!

I'm no expert so ill leave the diagnosis alone, however I can point you to the OBDII port! There are a few posts here regarding rough running issues and LPG dramas. Have you tried the search function? If you scroll down a few topics (and maybe onto the next page) I'm sure you will find something of help.

It is up under the dash in the LH (passenger) footwell.

[Hoges]

You've got 2 choices basically: jump right in and show him his old man knows a thing or two (or three) :p or tell him that you'll try and help but really...he needs to do a bit of research and fix it himself:angel::wasntme:

Beware: one or both of you is about to be afflicted with Range Rover P38a addiction...sadly there's very little hope unless you win lotto and buy a later model...in which case you get a new set of issues which cost even more to fix.. but the addiction stays with you forever.

Couple of hints to ease your pain: do a google search and download a copy of Land Rover RAVE ...several thousand pages of searchable workshop manual in pdf format. Indispensible.

Search "Storey Wilson EAS Unlock". Storey is a clever chap in the USA who has written a computer program you can download for free onto a laptop (MS Windows only, not Apple) and with a specially made cable (you can buy the necessary bits from JAYCAR), you can calibrate/faultfind /reset the EAS suspension (unless of course the vehicle has been castrated and is on coils...:censored:). As I said, he's made it available for free and it is accompanied with numerous Youtube clips demonstrating how it can be used.

Study RANGEROVERS.NET HOME (http://www.rangerovers.net) esp the P38 section. Dedicated sections also on common faults and fixes.

Sorry I can't assist with your LPG /petrol problems... there are genius rated professionals on this forum who are however most generous with their advice :BigThumb:

Good luck with your life changing decisions. You might even have to ditch the Toyota and buy a second P38:eek: Looking forward to further posts from you/son!!

[Armitage_Shanks]

G'day and welcome!

I'm no expert so ill leave the diagnosis alone, however I can point you to the OBDII port! There are a few posts here regarding rough running issues and LPG dramas. Have you tried the search function? If you scroll down a few topics (and maybe onto the next page) I'm sure you will find something of help.

It is up under the dash in the LH (passenger) footwell.

That's great. Thanks Keithy.:BigThumb: I'll plug in the scanner tomorrow and see what we get.
I've found some good stuff in the LPG section using the search function. But I'll sit down over a beer tonight and have another sift through all the information.

[jazzaD1]

since it affects the running when it is on petrol also, i'd be inclined to check the ignition side of things

[Armitage_Shanks]

G'Day Hoges
To tell you the truth, I had my first ride in RR Classic (a '73 2 door with a Fairey Overdrive) when I was 15. I was sold on Range Rovers back then. However, I've never personally owned one. Now that my son has bought one I'm seriously considering getting one too. My 4Runner is very long in the tooth and I'm getting older as well. I'd like a bit more comfort :D I might get an L322 though.

We were going to do the oil, filter, and coolant this weekend. I was planning on literally standing back and directing my son on what to do. Only getting my hands dirty if required. But I think I'll be spending the weekend getting the vehicle back up and running instead. We'll do the service later :(

Thanks for the tips. A one thousand page service manual will be great bedtime reading. ha ha.

[Keithy P38]

That's the way to do it! I bought my Rangie when I was a measly 24 years of age. Having tinkered with old Holden's and a few injected V8 commodores before getting the Rangie made it easier to get under and feel comfortable working on it.

Really they are no different to any car out there, just got a few more gadgets!

[Armitage_Shanks]

Yeah I think you're right jazza.
I've noticed the coil packs are right at the rear of the engine. That'll be fun.

[Keithy P38]

Out of curiosity is it a gems (pre '99) of Thor (post '99) Rangie?

[TheTree]

HI

I am no expert on LPG but I noticed that my LPG injection system has a relay which taps power from the battery, and an associated fuse.

Since it is dead on LPG but runs on petrol, it may be worth checking the the LPG system is in fact getting juice.

Steve

[bee utey]

A few thoughts:

The petrol system must run properly for the LPG system to get the correct signals to convert to LPG injection signals. Providing the wiring of the LPG system isn't faulty, ie the injector cut wiring is fully intact, then you need to concentrate on the petrol first.

Now if its only running on 4 cylinders, one of the coil packs may be unplugged. If the LPG computer takes its RPM signal off one coil (like I do it) and that plug wasn't fitted properly, it could jump off. I had an alternator regulator plug jump off my wife's car a few weeks ago, that was nearly embarrassing. So it's easy enough to do.

Without any other knowledge, I'd also be looking at a MAF (mass air flow meter) failure, especially if the mixtures are really lean or rich. LPG won't fire at levels that petrol will just manage.

[Armitage_Shanks]

G'Day again.
Just thought I'd update the thread with what we found today.
Using my OBDII scanner, I found a series of error codes. I reset the codes and we started the car. Immediately I got a code reading P0205 - Injector Circuit Fault on Injector 5. After driving the car for a short trip, we also got codes indicating running rich on banks 1 and 2.
So I think that's probably the root cause of the issues. A dodgy injector or injector wiring.
My son has it booked into a RR and Jag specialist for Tuesday. I'll update the thread with the outcome.

[Armitage_Shanks]

Out of curiosity is it a gems (pre '99) of Thor (post '99) Rangie?

By the looks of it, it's a Thor motor. Bosch engine management. That means its a Thor, right?

[bruce p38]

Right !

[glenhendry]

I support Bee utey's position, fix the petrol first! My guess will be MAF or intake air leak.

The LPG can cause all kinds of rich/lean faults and especially "injector circuit fail" faults that aren't true. The LPG system will try to fool the petrol ecu and confuse it.

[Armitage_Shanks]

G'Day again guys.
Just thought I'd update the thread before it gets bumped off the first page.
So, it took a while, but they found that the car had a faulty O2 sensor and a faulty injector #5.
The car runs really well now. Except - the LPG solenoid sometimes sticks. Other than that it's all good.

Thanks for all the help BTW. You guys are great.

[glenhendry]

Good news.

Strange that you got rich on banks 1 and 2, and only one O2 sensor was faulty?