Exhaust fumes smell of sulphur problem solved ?

Sorry but can't find anything Jimny specific on coil packs in my info, but plenty generic "how to test" videos on you tube, but not tried any.
ARC sound - coil packs?
Could be worth starting the engine tonight after dark with the coil pack cover off, you will certainly see any issues as arcs once the light has gone.
 

After a disaster at the local garage, total waste of time. 8 hrs in there, no fault found by them, and the suggestion it was dirty oil causing my problems. Impossible, simply because the engine oil had been done 500 miles previously!!
so back to my garage and time to investigate the original problem of very poor idle at running temp.
Removed EGR valve, not a easy task.  Removed all of the loom around it, this gave more space.
The valve wasn't that dirty really, but noticed the valve itself wasn't seating properly. Took the assembly apart, and found the spring was not returning correctly. A good dose of gunk /3 in 1 oil and a final clean up with petrol and jobs a goodun. Found that it was easier too re assemble by fitting the valve to the mainfold take off pipe first, much easier to install metal gasket. It also then held the valve body in the correct position too insert the 2 X 12 mm bolts. Loom re installed, and Jimny is running great.
I think in future if I have the problem again, I will firstly just remove the 4 screws in top of the EGR valve solenoid and manually check the valve is returning/not stuck.
I've added some pics/video.After a disaster at the local garage, total waste of time. 8 hrs in there, no fault found by them, and the suggestion it was dirty oil causing my problems. Impossible, simply because the engine oil had been done 500 miles previously!!
so back to my garage and time to investigate the original problem of very poor idle at running temp.
Removed EGR valve, not a easy task.  Removed all of the loom around it, this gave more space.
The valve wasn't that dirty really, but noticed the valve itself wasn't seating properly. Took the assembly apart, and found the spring was not returning correctly. A good dose of gunk /3 in 1 oil and a final clean up with petrol and jobs a goodun. Found that it was easier too re assemble by fitting the valve to the mainfold take off pipe first, much easier to install metal gasket. It also then held the valve body in the correct position too insert the 2 X 12 mm bolts. Loom re installed, and Jimny is running great.
I think in future if I have the problem again, I will firstly just remove the 4 screws in top of the EGR valve solenoid and manually check the valve is returning/not stuck.
I've added some pics/video.

  

 

Thanks for taking the time to feedback the cause of the fault, it's the only way we can learn.
Good news you got it sorted, but I am surprised it's the ERG valve at this low mileage and its not from what you said dirty. What's your opinion, faulty from new or previous owner / mechanic fiddling left it not seating properly?
Just interested so we can help the next person a little better.
TaMike

It could be because I drive like I'm driving Miss Daisy!! But in all seriousness, I think over the last 6 months it hasn't had a lot of use. Sort of once a week shopping trip (4mile round trip) so not been getting a good run out. The other possibility is perhaps my location. The sea is literally 600metres away and on the west coast, so constant salty rain blowing in a lot of the time. There was some salt corrosion on the alloy solenoid body, and the base of the valve spring was well gunked up.. I shall keep an eye on it. When I noticed the valve was stuck, it took some pressure to make it go up or down. I reckon I spent 20 minutes pressing it by hand and lubricating it before it free up properly.
One last thought would be the solenoid malfunctioned and then carbon build up occured.