Re:Bit of help needed here

Update:

I'm still no further forward with this annoying problem.

The journey to Shropshire at the weekend seemed ok but the journey back bacame steadily worse the further I travelled, particularly after ascending a steep 1.5 mile hill (Fish Hill at Broadway). Curiously I had made the same ascent of this local hill during the previous day with no problems.
The difference between this journey and the previous day was that the car had now been running for a lot longer (from Shropshire) and I was using heater fan and lights as it was getting dark - this was the exact same situation a month or so earlier when I nearly didnt get home at all.

Anyway, after the hill, the engine coughed and spluttered more and more. I briefly pulled over and tried recycling the ignition but it made no difference
I also tried slamming my foot hard down on the throttle - the engine would stutter badly before accelerating through the rev range.
I did get home but the car wasn't happy at all.
No warning lights and no codes.

Talking with a colleague at work the next day, he seemed to think there should be some kind of amplifier for controlling the coil-packs and thought it would be that - but I have never heard of these being mentioned in any fault-finding discussions on here.

I'm still in the dark with this problem

When you changed your plugs and coils did you do the leads too, also who supplied them? I changed my leads to some from euros a few years ago and they only lasted about 3 months before giving similar ish problems.

Hi Lambert - no - the leads weren't changed; just plugs and coils.

The plugs aren't the expensive iridium ones, but are correct NGK.
I can't recall the brand of coils but they're from a very reputable local motor-factors supplying local garages around here

I should add I didnt do the work myself - this was done by a good local workshop well versed with vehicles of this typle and agricultural machines

I see a set of good quality plug leads in your immediate future.

Yes I think I do too

Reading through this I agree with Lambert on the working through it methodically and the basic old fashioned component checks first.

The load on the engine bit could indicate the plug leads as the engine will be throwing in a lot of fuel with you at wide open throttle but the engine is labouring. It will need a nice fat spark to ignite all of that fuel properly and if it can't it will get wet plugs and run rough.

Jimny's can be susceptible to issues like this. If you start it and stop it straight away on a cold start, then start it again it may run rough. They do that. If you leave it 2 minutes or so it will be fine.

So I wonder, if you get it running rough when hot again, leave it off longer to see if it runs ok after 2 minutes, rather than just off and on again.

Pop new leads on anyway.

Kirkynut

Thanks Kirkynut.

Well it's turned out to be not good news

I caught up with an old RAF colleague of mine who was always a bit of an ace with electrics and he went over a whole load of tests.
His code reader found "random multiple misfire detected" and on further investigation found the front O2 sensor reading a high voltage indicating a rich mixture.
He routinely went through the plugs coil packs and HT leads and found them all acceptable, so went on with a compression test which gave the following results:

#1 Cyl 9.75 Bar (141.4118 psi)
#2 Cyl 8 Bar (116.03 psi)
#3 Cyl 9 Bar (130.534)
#4 Cyl 9.75 Bar (141.4118 psi)

So he thinks there is a good chance that there are burnt out exhaust valves on 2 & 3

Oh no! Cylinder 2 certainly doesn't sound happy. Time for a 1.6?

Alas, it will be as much as I can afford to fix this, nevermind a 1.6 conversion