I don't recall any carbureted engine using DIS (waste spark type) systems off hand.  The first I remember running into was on port fuel injection.  It does "fire" with every revolution of the engine.  At 2000 RPM it would be around 2000 times a minute or roughly 32 times a second with 2 cylinders (companion/sister cylinders) secondary having a spark plugs in series in that circuit.

RPM, load, and mixture play a part in spark delevery also.  Duration of the spark across the spark plug gap is measured in FT (firing time).  This ranges around 1ms (millisecond) to 5ms.  The FT varies with load (cylinder pressure) and fuel mixture (lean leaning towards the 1 ms range and rich towards the 5 ms range).

One of the things manufactures used early on to pass federal emission stationary tests was to put a park or neutral switch incorporated into the ignition/fuel system.  This allowed the "timing" to be retarded to produce less emission out of the exhaust.  Less cylinder pressure (les NOx), less emissions, and with some a smoother idle.

12 months ago, I bought a 1999 Mitsubishi Delica with a 4m40 2.8TD engine (diesel).

• The vehicle itself has done 120,000 miles and runs very well.
• There is a very slight oil leak somewhere.
• There is no service history with the vehicle.

I bought the vehicle as I am looking at converting it into a campervan and going on a round-the-world adventure starting sometime next year. I recently acquired a fully stocked workshop/car garage for the next four months to concentrate on the conversion.

Mechanics:

• As I now have space, time, tools and physical help, is it wise/beneficial to pull the engine out and give it a complete overhaul?
• If no overhaul is required, what would be your main concerns?

I have always done my own repairs and I can confidently say I can do the job, my main reason to ask is wondering is it really worth it?

My main worry would be any issues while on the road. Also, the timing chain as far as I am aware of has never been changed.

Thank you

Hello, as I was replacing the timing chain I noticed some orange color on the intake camshaft toward the back of the engine. Is this worrying ? I appreciate your help!

Picture linked below

There seems to be no power loss when I speed it up above 2000 RPM.

When I bought the car, half year ago, the previous owner told me that he replaced the ignition module and spark wires so I just changed spark plugs.

I tried to investigate this by myself: I rechecked all plugs, there were no carbon build up or something out of ordinary, I checked each spark wire and they too seem to be good (no cracks, etc...). But I have noticed that there is spark coming from the connection between one spark wire and ignition module pin. First I thought that the wire boot might have microcracks, but then I switched the wires and again the spark was coming only from this one exact ignition module pin. I unscrewed the ignition module and inspected it but there were no cracks. I sprayed dielectric spray on all connections but this didn't help.

I am sorry if this is a dumb question, but could it be that the wire boots are too short for this ignition module pins? Or is it more likely that ignition module is the problem and I should replace it?

This is how the wires and ignition module look: