Keep persevering! You’ll figure it out. Yes, make sure your cruise control vacuum lines are plugged (if disconnected). Spraying something like carb cleaner is a tried and true method of finding intake leaks, not just on LR’s. As you noted, be careful of fires.

 

Those "chips" are resistors. They are used by LR to define the engine tune for various markets. They change some of the base specifications.

This base idle screw is already uncovered in your photo. Looks like it has been previously adjusted, or just messed with.

 

How confidant are you on the MAF hose to plenum connection? It's a little askew. Doubt it's sucking unmetered air but hey, worth checking.

 

Ok sorry been a while!.. Still no further forward with this. I removed the idle control screw and cleaned out that passage, it was pretty filthy so was hoping that was the issue, no change. I have checked what I thought was bad wiring on a few key parts, injector, coolant temp sensor, fuel temp sensor but they are all fine, just an ugly finish on the job but inside the wiring it secure and tight. I've tried swapping the coolant sensor connection with the fuel sensor connector in case they got muddled at some point, no change there. A friend suggester marvel Miracle Oil in the tank, it's had a few gulps of that, no change.

Thanks 'CantComplain', yeah that's all fine I had undone it before I took that shot, should have mentioned thanks / sorry.

I've been looking at the distributor more closely, the job of moving the amplifier to the right side of the radiator has been done but the distributor is not using the dummy amplifier supplied. There is just some tired looking wires and a half damaged connector running between the distributor and the amplifier. In the parts that came with the vehicle from the previous owner (who owned since 2000) there was a bag with a used (perhaps the original distributor) the dummy amplifier and the brand new harness to run between the dummy and the relocated amp. I can't understand why they decided to do it this way when all the components are there to do it neatly and correctly. My on thought is that maybe the pick up in that spare distributor had and issue? (possible?).

If this was a distributor / pickup sensor issue / amp issue would I not be experiencing deeper issues through the rev range over than a rough random idle?

I've attached photos on the link below of the spare parts and how the distributor is currently set up.

https://photos.app.goo.gl/J3YjyE3EL6oXn1Py8

I've also got a random purple wire come from ECU side of the cabin, it's been wrapped around the jack (could be to do with fog lights, it's go some pretty serious ARB lights on the the bull bars but no connections for them to hook up to, In the cabin I've taken shots of a loose connector floating around and another which has been tinkered with.

https://photos.app.goo.gl/prBukDLpctirfDFBA

I've looked into the cruise control, I used to have a manual one in South Africa but this is a US auto, from what I recall on the manual it was hooked up to the clutch pedal (somebody had hooked that one up to the washer fluid so after multiple clutch pumps your feet would get wet ..), I couldn't see anything on the pedals of this Auto one, what should I be looking for?
Under the hood i don't see any hoses for the cruise control. I see these two coming from the cabin but do not connect to anything (third photo on link below, hoses are beyond the stepper in the back).

https://photos.app.goo.gl/r4j35yBvqzmjGVFt7

If you think I'm getting off trajectory here with the distributor any other suggestions moving forward?? Thanks to everyone as usual!

 

I would check the gap between the reluctor wheel and the pick up inside the distributor. If it is too wide, that could cause idle problems. Make sure base timing is set correctly, spec is 5 deg btdc, you'll need a timing light with the vac advance disconnected. There isn't much room there to aim the light well. I recall an online video LR mechanic sets it to 10 deg btdc to make up for timing chain stretch. Did you ever measure base idle? Base idle and base timing are important. I would check those before opening up the distributor. Let us know the numbers.

You mentioned a chip between the coil and pickup sensor. Rave doesn't show any resistor there, and does show shielding around the two wires from the amplifier to the coil. The resistors go from the coil to the ECU (and Speed Trip for manual transmissions). Check the wiring diagram carefully in case the PO messed up.

One other thing I noticed about the PCV tee. The orifice going to the plenum is a specific size. If it has been hogged out and too big, that could cause idle problems. Maybe get a new one.

Hope this helps.

 

I think you're on the right track with the distributor. I go through a new amplifier at least once a year and one of the precursor symptoms before total failure is hunting idle. When my amplifier or pickup is on the way out I also notice the rpms drop when turning the wheels back and forth while stationary. The power steering pump takes energy from the engine and the weak spark can't quite compensate.

Also - just one more plug for RoverGauge. Once you visualize all of the EFI sensors on that system and confirm all of those are okay, distributor and timing would also be next on my list.

 

Do the Bosch BIM024 module conversion. Mine idles better afterwards, and they are reliable! I had the factory remote mounting, so just cut the wires and fitted spades and pushed them onto the Bosch unit.

 

Haven't had a failure in 6 years of weekend driving ownership, but replaced my original module a couple years ago with a $25 unit from Lucky8, so I have a known good spare in my trail parts bag.

 

One other thing to consider - make sure your ignition coil is actually wired correctly. I accidently switched my positive and negative terminals in chasing down something else recently. To my surprise the car still ran (albeit with some idle hunting) and other symptoms.
Positive side of the coil = green/white wire (and positive for amplifier)
Negative side of the coil = black/white wire (that potentially links to a blue/white wire) as well as the negative for the amp
Attaching a diagram I've been building to help myself understand the 14CUX system for 94/95

 

Thanks for the diagram. I'm thinking if the coil is swapped around, we end up with negative high voltage rather than positive high voltage. Either way, a spark is produced. Maybe would affect spark plug wear in the long run?