Pulled the battery this evening and checked all the connections behind the black box (yellow, blue, grey connectors) and all looked in great shape. I’m assuming that’s where the ECU is? It was difficult to get to the two lower screws holding the cover but managed to prise my way in. Unless I was looking at the completely wrong thing.

Replaced the ignition capacitor but that’s not changed the situation either.

:/

 

I did not even look it up, but RAVE says 0.04" or 1.0mm.

 

Your next bet would be to verify wiring is intact, that connectors are good, etc. Its also maybe possible the ECU itself it damaged in some way. I really dont have any other ideas at this time since the misfires are so specific.

 

Thanks Dakota. Really appreciate the help. I’ll check and see if there are any anomalies I can locate.

I’ll give my LR specialist a call tomorrow and see if he has any ideas worth trying as well.

 

As a thought could it be dirty injectors causing this? First time it occurred we were in rural VA in the summer on a lot of dirt roads kicking up a lot of dust. We had to get back to PA and one our return and after refuelling the warning lights had gone. We put it down to bad rural fuel. We haven’t done any sizeable journey for a while so wondering if the short trips could have let to a build up again?

 

Weird conflicting info:

Downloaded PDF User Manual that states: NGK IFR5N-10, 1.5 mm (.060") gap
Actual Book Manual in my LR3 states: NGK IFR5N-10, non-adjustable
RAVE states 1mm (.040") gap

Guess I would go with them as-is, out of the box . . .
Would be nice if someone had some clarification on this one.
Even if just for me :-P

 

Could be the injectors too. You could try a few things. First is Seafoam, its the one "snake oil" that I swear works really well. Add it to the tank, let it run for a while so it can cycle through all the fuel and park it. See if it helps the next day sorta thing. Another trick is to put in E85 fuel, the very high ethanol content is actually a great fuel cleaner. Put a halftank in. You do not want to drive it hard while that fuel is in there and the vehicle may seen doggy with reduced fuel economy. In fact part of the reason why the V8 4.4 tends to gunk up anyway is because most premium fuels lack ethanol, so they tend to have less fuel system cleaning ability. But there is also injector/fuel rail level sorta cleaning using BG 44k (I think that's the name). But from what I have read it does damage the spark plugs in some way, so people go as far as to using old plugs/installing cheap plugs for the cleaning process. I have never used the kit, no clue how it work on the LR3.

 

I've had good results with BG44K. It's what LR use in their (a-hem) 'injector service' and is used widely to give the fuel system a good dig out. Many dealer shops use it as part of the service plan. I've used it - I think - to good effect on all my petrol vehicles once a year or so. Lots of reviews of both SF and BG online so do your own research. I haven't seen damage to the plugs.

One more thing you might consider if only because I've made this mistake myself as I found when I had exactly the same problem you're having: it sounds daft but it's worth checking that a spark plug crush washer wasn't left in the head when the plugs were changed. Engines will run with the extra washer in place up to a point but will destroy the electrode on the plug, which can quickly cause a misfire. I had this happen when a crush washer got left behind in my VW. It started to misfire after maybe 4000 miles. I changed the MAF, bought a new coil and moved that about. When I went to check the plug gap I found the washer.

 

Sorry, should clarify. The treatment that can damage the pugs is the setup used directly into the rails/injectors via some sorta hardware/machine setup. Plugs are fine for fuel tank additives, including 44k.

 

I’ll give the Seafoam a go and see what happens.

spoke to someone today and they said they’d have followed everything I’ve done and at this point would be scratching their head too.

I did try 44K but I think the part that was missing was the Italian Service part; fast and aggressive!

I’ve seen the fuel rail set up videos, but not sure I want to start messing with fuel lines just yet.

I’m assuming if the injectors are shot it’s no easy task to replace. I can’t seem to find any videos or guides.