Hi folks, any help would be appreciated on this one, having read other threads about misfire problems to no avail.

Apologies for this lengthy explanation in advance, but here goes.

So today, I am travelling on the M4, heading for Wokingham, a journey of around 130 miles. I have covered nearly 90 miles, cruise control on, doing around 70, 73. Five minutes earlier I had accelerated a bit hard to overtake someone in the inside lane. I am now in the middle lane back to cruising again, when I feel the car stutter a little, then begin to lag, engine management light has now lit. No throttle response at all, just slowing down. I move into the inside lane and pull onto the hard shoulder coming to a stand as the engine cuts out. I turn the ignition off, then after a few moments, I start her back up with no problem. I rev the engine and all seems fine apart from the engine management light still on. I pull away on the hard shoulder accelerating nice and smooth with no judder or lag. I know the next junction is only a mile away, so decide to get off the motorway at that junction to investigate. Now, I had carried out my pre journey checks of the usual oil and water, all ok. Finding a safe spot to park off the motorway I decide to turn the car off and wait for it to cool down before investigating. I also contacted the "AA", to get them out to check it over anyway, in case of doing further damage.
On arrival, I explained to the "AA REPRESENTATIVE" what had happened. He plugged in the diagnostic and pulled off the following:-
P0171 - system too lean (bank 1)
P1074 - system too lean (bank 2)
P0301 - cylinder 1 misfire

At this point he must have cleared the fault code, as the EMS light is now off.
He then said, I will contact Land Rover in Reading to see if they have a coil pack, if they have I will go pick it up and replace the one suspected to be .
I then listen to the conversation he has with the Land Rover Tech, who says, "No, it won't be the coil pack, it will be more than that, from those codes you have given me", ( I could hear him chuckling as well ).
No replacement coil pack was available, so the "AA REPRESENTATIVE" said, "Not alot I can do for you, other than arrange recovery", which he did.( 2 hour waiting time for it but nothing to be done there other than suck it up! ).
He also said, "while I am here, I might aswell have a little dig around to see what I can find".
Fair play, I thought.
No sooner had he arranged the recovery, he got out of the van, put the engine cover back on and said, "Not much more I can do for you really, other than you wait for the recovery truck".
I thought, that's a great help!.
Anyway, the recovery truck arrives and Independent Recovery guy drives the car onto the transporter, ( top bloke actually, "Scoobie", from 24-7 recovery).
Two and a bit hours later, home, off the truck and onto my drive.
I now decide to take the car for a little spin and it seems to be fine, no misfire, judder or lag and no EMS light back.

Now I was thinking about just buying a coil pack and replacing number 1, but after taking it for a little run I am not so sure.

I don't have a code reader, so am unable to swap coils over to see if the fault moves, EMS light off anyway!.

This is where I am now at a loss, don't fancy taking it to a garage if the EMS light isn't even on and it seems fine.

It's a 54 plate Vogue 4.4 petrol.

Any ideas what it could be guys. I am a bit bummed cos it's been an expensive day already with no reward.

"The pleasure of owning a Full Fat, I hear you all cry".  "I got him boxed in like a turtle's pecker!".

Sounds to me rather than a coil pack jiggered it's more likely to be a lamda sensor as a misfire would cause more unburnt fuel and therefore "system too rich".........anyways lambda are cheaper than coil packs.

Jonno 5.0 supercharged autobiography
Gone-4.4 Vogue Lpg now unmapped
4.6 HSET Turbo Lpg mapped
Gone-Defender 90 200tdi
Gone - 3.9 Sprintex supercharged LPG
Gone - 3.9 Vogue LPG

[]

Thanks for the reply Jonno.

Now I think about it, I am sure I heard what sounded like it backfiring, well certainly popping in the exhaust.

That could have been a result of pressing the throttle when the engine was stalling maybe?.

All a bit strange really. "I got him boxed in like a turtle's pecker!".

How much fuel was in it?

If the whole of bank 1 & 2 were lean its likely something starving fuel supply but only enough for the single cylinder misfire (at that point).

Just wondering if you have a faulty fuel pump or blocked fuel filter.

Also:

A code P0171 may mean that one or more of the following has happened:

The MAF (Mass Air Flow) Sensor is dirty or faulty Note: The use of "oiled" air filters may cause the MAF to become dirty if the filter is over-oiled. There is also an issue with some vehicles where the MAF sensors leak the silicone potting material used to protect the circuitry. (Clean or replace)

There could be a vacuum leak downstream of the MAF sensor (check)

Possible cracked vacuum or PCV line/connection (Have you replaced the PCV hoses?)

Faulty or stuck open PCV valve (replace)

Failed or faulty oxygen sensor (bank 1, sensor 1) (replace)

Sticking/plugged or failed fuel injector (Try adding a quality fuel additive injector cleaner)

Low fuel pressure (possible plugged/dirty fuel filter!) (clean or replace)

Exhaust leak between engine and first oxygen sensor (Check & repair)

[]


Thanks for the reply Gazellio.

The fuel level was just over a quarter of a tank when the incident occurred. I started the journey with just over half a tank, so had covered Approx, 80, 90 miles on a quarter tank. I recently Put Redex treatment in the fuel. Is that stuff good enough?.

The PCV hoses were checked a couple of months ago when I first bought the car and they looked pretty new to be fair, they did not feel spongy, no signs of breakage and still had the part number stickers on them.

The air filter is standard.

Sounds like a few other things to check but it ticks over really sweet and quiet.

As I said earlier, when I got home, I took it for a run and all seemed fine. Perhaps as you said, maybe a momentary fuel problem, picked up a bit of crap from the tank maybe?. "I got him boxed in like a turtle's pecker!".

I asked to see if the fuel level was quarter tank!

You may well have a problem with a faulty "JET" pump which moves the fuel from one side of the tank to the side with the main fuel pump.

If this is faulty (common) you will get fuel starvation at 1/4 tank.....

Fill it up with fuel and keep well over 1/4 tank all may be OK but you will need pump checked/replaced.

PS: I would also check the fuel filter is clean.

Gazellio @ Prestige Cars wrote:

I asked to see if the fuel level was quarter tank!

You may well have a problem with a faulty "JET" pump which moves the fuel from one side of the tank to the side with the main fuel pump.

If this is faulty (common) you will get fuel starvation at 1/4 tank.....

Fill it up with fuel and keep well over 1/4 tank all may be OK but you will need pump checked/replaced.

PS: I would also check the fuel filter is clean.

Cheers Gazellio. When I bought the car, the chap mentioned about that issue with L322's but I have tried to keep it above that quarter tank mark at all times. As it hadn't even got to the quarter mark I didn't think about that. It was bloody hot weather yesterday, so the gauge may have been a bit higher than actual tank level, so possibly was below quarter?.  "I got him boxed in like a turtle's pecker!".

Last time it happened to me at the very top of the Woodhead pass I ground to a halt and the engine would not run for more than a few seconds. However half an hour later I was able to start it and drive nearly two miles to the shell garage near the M1. THe Jet pump may overheat and stop working then cool down and work again (for a while) This may explain you starting the car OK after it has been recovered.

Jet was faulty and replacing pump fixed it completely.

Sounds indeed like the balance pump issue, very common on FFRRs. At least it is the first thing I'd suggest to address. Running fuel injector cleaner, using "clean fuel" and changing filters is a good way to go anyway but you are likely looking at the fuel pump unit here.

Suggest to scour the bay for new pumps as they aren't cheap from the dealers. I suggest to ask Duckworth Dan for a price as well, he seems to have the lowest prices around usually. MY 2010 5.0 SC Galway green and sand interior!!
Have the Faultmate MSV2 Extreme to be tinkering with the settings etc. !!

Thanks for the help guys, sounds like I need to look at the pump and fuel filter then. "I got him boxed in like a turtle's pecker!".

The "cheapest" temporary solution is keeping the tank above 1/3 full for a while and see if you have any issues. MY 2010 5.0 SC Galway green and sand interior!!
Have the Faultmate MSV2 Extreme to be tinkering with the settings etc. !!

[ mod edit, there is no need to quote when replying to the above post ]


Good call, thank you ebajama!.

 "I got him boxed in like a turtle's pecker!".

Thanks mod, will bear in mind next time.
 "I got him boxed in like a turtle's pecker!".

@simusmaximus: was your problem solved? if yes what was done to solve it - seems like i have a similar problem with my 2004 v8.

it runs well, then misfires and couple of times the engine management light flashes. fault codes are similar to what you have in your OP.

In my experience, if it's not the JET pump issue, it's often the Mass Air Flow sensor. They seem to pack up at high milage just for fun.

Had exactly the same symptoms on mine a few months ago - new sensor (get Bosch, i.e. genuine not pattern) and engine light went out and the car's been fine since.