Sporadic ignition issues on a cursed (fixed) 2004 DDIS Jimny

Hi everyone,

I am the owner of a cursed 2004 1.5 Jimny DDIS 65hp which does run, well most of the time, after 212 000km.

Ever since I had the HP pump and injectors replaced 4 years ago at around 120k km, the Jimny has had sporadic issues to ignite. It's not completely random, it mostly happens when the engine's cold, and when it rains hard. I live in a tropical country and over the last years I've noticed it mostly happens during the rainy season.

I always manage to ignite it after a while, it can take up to 30 minutes and when it does ignite in those cases, the battery light is on, the engine idles in an unstable way at around 6-700 rpm and pushing the throttle pedal does not have any effect. I put it in first gear, release the clutch, the rpm goes down, push the clutch pedal again and when the rpm comes back up the engine idles normally and I can drive, interesting, huh?

I've started learning about cars working on this Jimny with a friend who's a mechanic and he is at a loss with that issue.

Would you, Jimny experts, have any idea where to look?

The fact that you have correlation between wet conditions and your issue makes me want to say it's electrical,so a sensor isn't sealing properly or some such. Unfortunately we didn't get the diesel version in the UK so my knowledge is very limited on where to start looking.

Diesels do not like air in the system. To me this sounds like there is a leak in the system so air gets in. there could be a leaky connection somewhere that lets in air and the pumps do not handle this very well..

Do you park the car differently in the rainy season?
My VW did not like when the nose was higher than the petrol tank parking uphill. could be very slow to start. but when parked in a flat surface or downhill it started right up. a slight leak in the diesel channels in the cylinder head made the diesel flow back out of the system so there was nothing to start with.

Depending on the system and where the leak is the diesel might even just flow back to the tank or into the cylinders like mine so there is no visible leak.
Finally on my T5 there was so much leakage that the diesel went into the oil, making the lube thinner, pulled it into worn Turbo making it spin out of control in a run off. just barely saved the engine by keeping a cold head and choked it before it blew or seized thanks to the sixth gear and good strong clutch. The repair still cost me 80000,-NOK (half the worth of car) wich is 8000£ for a new turbo, IC and cylinder head. 

Thanks for your insightful replies.

The car is always parked in the same spot, a evenish place outside, in the blazing sun or the pouring rain depending on the season. We thought of the air leak hypothesis, but in that case, using the manual fuel pump that's just before the filter would help, wouldn't it? I've tried multiple times to press that pump like a madman when the car wouldn't ignite, to no avail.

As for the sensors, which one(s) would have the effect of preventing the car from igniting? Only camshaft and crankshaft sensors or others could be the cause of the problem? If it could come from those two only, I'd be willing to give replacing them a try and spend 150 euros to fix that problem for good.

I'm going to borrow my friend diagnostic tool later this week, so that I'm able to plug it in when the problem occurs. Would a sensor issue or an air leak show up in the diagnosis? If so, could you point me to values I should look at to confirm either of your ideas or come up with others?

Oh and I asked my wife, who occasionally drives the Jimny (which she bought in the first place), and she reminded me that the last time she really struggled to start it was on a perfectly sunny day, after having driven 40-something kilometers...so it does happen completely randomly sometimes...

I've just read Bosanek's page on "Key, Immobilizer..." in the wiki. Could it come from a random failure of the immobilizer system?

I do have two keys and tried them both when the problem occurs, it's unlikely the transponder chips in both keys would fail at the same time. Could the antenna coil work intermittently? As there is no immobilizer light on the dashboard, I'd have no way of telling it's the problem.

Again, would such an issue show up on a diagnostic tool?

Sorry for the multiple messages, I'm really trying to get to the bottom of this, after 4 years, it's high time I found a solution.

Like I said I don't know enough about one. I take it they are electronic injectors and not mechanical as a p pump type diesel should just work or not... Whereas an electronic common rail requires signal and feedback from an ecu and sensors. Sorry I can't help more but I'm sure someone with more relevant information will offer assistance.