Over the last few trips, the van has developed a really poor idle. Once off of the choke, intermittently the revs drop to approx 500 ish, and it's barely ticking over.
At this point, the engine rocks in the engine bay.
It doesn't always do this though, but another symptom is stalling at lights when slowing from speed sometimes.
I thought I would start with basics first, and thought perhaps air leak. Used the carb cleaner to check for increasing revs while it was running rough - no bueno.
Today I went with dizzy cap, rotor arm, leads and plugs.
Started with cap, leads and arm - no bueno. Issue remained despite the arm having clear scorch marks on it.
Here's the kicker.... Took out the plugs to change, and they are all sooty.... Very sooty.
No oil, just black hard build up on all 4. The weird thing is, they are labeled as R6 Bosch, not the WR7 DC+ I have found others comment on via forum searches, and the ones BW send out.
So the question is; what vehicles are these plugs used for ( if any VW camper ) and could they be causing weak spark to enable carbon build up?
I've changed the plugs for new WR7 DC+ and it runs nice. Going to have to go for a drive tomorrow to see for sure as symptoms are intermittent.
My thoughts are, if the plugs are not issue, or others here feel not likely, then I am more inclined to think there is another underlying issue that will result in same symptoms eventually returning.
Pics below - let me know thoughts:

