intermittent ignition

[chasbmw]

If you forget to mark the bean can before removing, you can time it on the S mark, by using a timing light and running the engine on the starter with the plugs removed and grounded. When running recheck on the F mark.

But even simpler is to rotate the bean can until the engine catches, then time by ear, recheck when you get access to timing light. No need to use the BMW tool or it's equivalent

[BMWARCHER]

thanks for the timing procedures. I did the mark and retimed with a light.

[Phaedrus]

....The battery connections can be the culprit, if just slightly loose, or rubbed through earthing somewhere

From info supplied I doubt you have a bad battery cable but I'd confirm the quote. My R90 would die on me. Battery cable "looked" OK, but turned out to be the culprit. Dealer couldn't successfully trouble shoot. I replaced the cable because I could do a roadside fix just by flexing the cable. The fault was way up inside the cable, not visible at the ends.

[BMWARCHER]

I have had cables that were corroded through up inside the insulation, this time it was the "bean can"

[Duane Ausherman]

We found that failure early on. The contractor didn't know how to crimp and BMW didn't inspect them.

My article has some of the information, but it too isn't complete. I will fix that when I get around to adding the large amount of information stored up on my computer. Go to http://www.w6rec.com/duane/bmw/terminal/index.htm

Here is a professionally made video that is only a part of the information needed. It even has a few errors. https://www.youtube.com/watch?v=b9MUfemfZY0

NO-OX must be used on all connections on your BMW. This is especially important with the battery cables, as they were the first ones to fail. Some not more than a year or two old.

I prefer to heat up the stripped off wire and allow the NO-OX to wick way down past the insulation. That provides a barrier to air. Air is laden with moisture, the enemy of a connection. We in the wireless industry are required to use terminals with an inspection window. That assures that the wire is fully inserted.