XJ 1998 VM 2.5 turbo diesel - limp mode?

[amlav]

There was another post here by Luminol related to gear shifting issues .
It sounded like the clutch master cylinder needed bleeding but he never came back to let us know to confirm it .
Croitoru... don't despair , just take it easy . Pull apart things and examine . You won't get answers that would pin point how to solve your issues just suggestions . People here assume that op's get dirty and rip in to it until problem is resolved . You sound a keen guy not afraid of oily hands and therfore I would say don't be afraid just rip in to it bit by bit and be calm ,don't rush .

[croitoru]

Hi
Finally life gave me a break and took it into my trusted transmission guy, Clint@Hart transmission in Brendale (thank you state if Queensland for Ekka break).
I had to drive there in second, of course.
Then he took it for a spin and managed to shift it in 3rd, 4th, 5th, multiple times. By slightly pulling the shifter up.
He said there's likely nothing serious.
I'm going to ask him if he knows any good diesel mechanic up this way.
I will post results re transmission final root cause and fix as soon as I have it.
Cheers,
R

[amlav]

Originally Posted by croitoru

Hi
Finally life gave me a break and took it into my trusted transmission guy, Clint@Hart transmission in Brendale (thank you state if Queensland for Ekka break).
I had to drive there in second, of course.
Then he took it for a spin and managed to shift it in 3rd, 4th, 5th, multiple times. By slightly pulling the shifter up.
He said there's likely nothing serious.
I'm going to ask him if he knows any good diesel mechanic up this way.
I will post results re transmission final root cause and fix as soon as I have it.
Cheers,
R

Regarding the gear shifting : It is very easy to remove the gear lever unit from the gear box (from the inside of cabin) . Remove center console , remove the rubber cover edges and push rubber cover up the lever .
There will be as far I remember 4 bolts to remove and the lever should come out. At the gearbox end of gear lever there would be a small plastic type coupling (squarish - that was broken on mine).
As you select the gears the coupling slides and moves the gearbox forks inside . Maybe it's worth looking at it .
That would be pretty much all you would be able to inspect the rest would be to do with gearbox internals .

[croitoru]

Amlay - thank you.
Turned up it was the plasticky thingie you suggested... but wait, there's more!
The selector fork was funked, deep groove (aluminium) which explains the shiny look if the first gearbox fluid change.
And while at it, the clutch was kooked as well, also clutch springs broken... also seals ( including rear main)... rear lsd rebuilt (broken metal bits floating in the fluid, cracked gears, etc)
So a lot replaced and Clint reckons drivetrain good for 200k km now...cost, better left out of the discussion. He's really good so he cut me a deal. Took it for a drive up Mt Glorious today (and have been driving it daily for a week) all good, still a heavy manual truck. Climbed and drove fine as long as I kept rpm bellow 2k.
However...I asked Clint and he took it to a diesel specialist mate at the same time, but no cigar. No codes, tried egr blocked/unblocked, etc. It's clearely fuel restriction above 2000-2100 rpm. His mate scratching head, said either injectors or fuel filter.
Not sure what to do next, I guess fuel filter (no idea how old/condition, so might as well)
The more I drive it, the more it feels (of course could be placebo) that it gains just a bit more rpm before it starves.
It's clearely a fuel delivery problem because I drove behind it in my ZJ and I can see very little and very seldom any smoke even when downshifting on climbs.
It FEELS like an electronic sensor problem, restricting fuel at 2k+ RPM.
R

[amlav]

Glad to hear that part of the issue was fixed . To try and sort out the fuel issues I would start with replacing the fuel filter .
Make sure there is no air getting in to it (seal has to be perfect).
Air also can get in the fuel system if injector(s) are faulty and don't close properly .
Fuel filter issues still would allow the engine to rev up in neutral but maybe not under load .
Clean the MAF sensor and replace the air filter .
Check number 1 injector by measuring the coil reading (should be arround 120 ohm) . If there is no reading than that could be the problem . Engine management computer will not let engine to rev up over 2000 rpm if doesn't get the signal from the needle sensor inbuilt in to injector 1 . Also check the electrical connections on it - including connectors too).
Some say that sensor can be baypased connecting a 100 ohm resistor in parallel on the 2 wires . (not sure about it , mine is still ok ).
If all above ok than only thing left would be injection pump (hope not).
Can you rev it up over 2000 rpm in neutral ???

[croitoru]

Actually that's a very good point, and thank you for highlighting.
It's probably the relevant engineering differentiation I should research on.
Based on your hint, Amlay (thank you), I realised that the fuel underdelivery issue ONLY happens under LOAD. I don't know what it means yet, but It think it's a HUGE troubleshooting clue.
Revs fine (3000+ rpm) and have (some) black smoke in neutral, stationary.
So I guess perhaps the next step would be to understand what sensors come into computer calculations as input for load-based decisions, and go from there? I've checked #1 resistance before and seems fine, but the wiring looks like it might have been worked on before (possibly same troubleshooting?). Maf looks clean but I will recheck. Also, I bled the fuel pump before didn't make much difference. I also guess airfilter and maf would cause the same issue both under load and in neutral? Although you say that fuel pump/injector could cause this exact behaviour ( RPM fine at neutral but limiting under load).
R

[layback40]

Have you replaced the fuel filter element yet? No point in any further trouble shooting until you have done that. When you replace the element it would be worth blowing back the fuel line with compressed air. Make sure you have the fuel filler cap off when you do it. This will clean any blockage out of the strainer in the tank.