Club 80-90 Forums

Few questions to help me learn about a new to me JX engine.  Last van was 1Z TDI engine so completely different and I know that one had too much power for its own good!.   Main symptoms last week were no power up hills.   The drive back home after picking up van showed I could cruise along the flats at 55 to 60 but at the slight hint of a motorway incline (M1 midlands south not the hilly north) then I would drop to 50 or so but still not pissing off lorry drivers.  At first put this down to being so lucky with a 1Z in the last van and the JX is not as powerful.   A few days later have had a run up for camping to the proper north where I was dropping say from 60 to 30 in a few hundred yards on the A68 in Co Durham.  Now I know this is not normal so didn't dare continue up that road and continued North to Scotland via the coast.

So had a google what could cause this and first suspect is the LDA.   Well the hose to it was loose at the inlet manifold so that may explain things.  Put it back but  at the time had no hose clips handy in that size so nothing to stop the pressure popping it off again.  Revved engine a few times and LDA arm still did not move despite ensuring hose was in place.  Tried putting my finger on the inlet and extending the LDA arm and it will not hold its position.  YouTube suggests that deffo indicates a bad diaphragm.  So I  ordered a rebuild kit due in on Monday from Germany.

 Now today I am back home.  Removed the LDA completely so I am ready to fit the repair kit when it arrives. Strangely the ball joint was held on with cable ties so one more thing to put right but for now I will ignore as the cause of my problems.   From previous posts I thought I would try pumping air from a bike pump into the LDA to see what happens.   The LDA does seem to open - not as far as I can pull it with fingers but it does open about half an inch at a fairly low pressure which is still more than I can blow with my gob. Stays open with a sustained lowish pressure but still will not hold position if the input spigot is blocked so I still think it is leaking.

 Hoping someone who has read this far may be able to tell me if this may be normal for the JX LDA even though I think it is punctured.  I was expect the bike pump to do nothing as the return spring in the LDA seems pretty strong.

 Busy tomorrow but on Sunday will be having another look to make sure the blow off valve on the intake manifold is not stuck open as other posts suggest that could explain lack of power too.  Also have some 9mm hose clamps handy to ensure the hose stays where it is supposed to.  Think I may have an old vacuum/pressure gauge some where so will dig that out but I have a feeling it is no longer anything close to accurate.
 
I am pretty sure the turbo itself is OK as I can feel it kick in at lower speeds in 1st / 2nd gear.  Just nothing at all where I need it in higher gears.

 Let me know if anything else I should be looking at since like I say this is a new engine to me so bit of a learning curve. Initially I just thought LDA but now I am not so sure. Just hoping there is someone else here who has been here before.

Pull the arm of the LDA. Then put your finger in the spigot. If the arm
moves and closes then its a leaknin the rubber diaphragm.
They are a fiddly pain in the ass to change.
If your lda has all the nuts round it. Then it will be easier.
Do not twist the rubber when putting it back together.
Use a soldering iron to make the holes not a drill - otherwise it will tear almost immediately.

Thanks. So it does sound that I definitely have a leak as if I put finger over spigot to block it the it just returns back when pulled out. Parts should be here on Thursday. Good shout on the soldering iron but have ordered a set of leather punches. The whole assembly is now off van. Instructions in English come with the kit but I think I need to drill holes around flange to bolt it together once done. Then grind the lip away which is currently holding it together as these were never intended to be repaired.

pirate-pete wrote: ↑30 Aug 2025, 15:55 Thanks. So it does sound that I definitely have a leak as if I put finger over spigot to block it the it just returns back when pulled out. Parts should be here on Thursday. Good shout on the soldering iron but have ordered a set of leather punches. The whole assembly is now off van. Instructions in English come with the kit but I think I need to drill holes around flange to bolt it together once done. Then grind the lip away which is currently holding it together as these were never intended to be repaired.

I had the same problem on my JX , it was very flat no boost at all. I looked at the repair kits but I thought it too much of a pain in the ass and probably still wouldn’t work properly after all the hassle. I bit the bullet and bought new one from Gunzl in Germany , bloody expensive btw. Anyway I fitted it and the boost is great now , it’s 10 times better . Good luck with the repair . Let us know how it goes .

My understanding is that all the JX LDAs now come from Dieselkontor.de as they own the machine that makes them. Their list price is also the cheapest and they offer different versions for different types of vehicles. However, you’ll probably find that the total cost with import duties works out the same as Brickwerks.

clift_d wrote: ↑30 Aug 2025, 19:44 My understanding is that all the JX LDAs now come from Dieselkontor.de as they own the machine that makes them. Their list price is also the cheapest and they offer different versions for different types of vehicles. However, you’ll probably find that the total cost with import duties works out the same as Brickwerks.

Aye - I came across similar info too pointing to Dieselkontor.de but at the price I thought I would try a repair first.  Can always buy the whole thing if the repair works out bad.  The repair kit was £34 from Germany including DHL shipping. Have yet to see if any duty gets added. Was looking at the German forums too to get an idea of the process but have since found a write up here Beginners guide to lda repair.