Maybe this has been done, and maybe not -- has anyone repaired a plug wire on their late 80's 750il? These have to be the most complex wires -- plug side has a long insulator with a rubber boot. The normal wire section snaps into that insulator assembly and has a retaining clip. Then there's the round insulators (beads, looks like an abacus :)), the cylinder signal wire (on wires 6 and 12), then on the distributor cap side the normal wire section snaps in to that boot assembly.

Anyway -- here's my main question. For someone who has done a repair on these -- are you supposed to be able to just pop the wire out (with a bit of pulling) from those end sections? It seems like they were designed to, but on some practice wires I picked up cheap, I have been successful in doing so once and twice the crimped wires at the end of the center section have just broken out of the crimp, leaving the connectors stuck on the boot assemblies (and they are basically impossible to pull off, even though it looks like they are designed to pop off).

Any ideas, let me know...the problem is, I want to rebuild the #6 wire because the cylinder signal wire broke -- I have a new signal wire, but we've gotta get it onto the existing #6 wire. I could just buy a generic wire and replace it, but it's my brother's car and he would like to use the original wires with the nice insulated ends. And money is an issue -- he isn't ready to drop money on a new set.

Get one from a junk yard.

Those wire and plug changes are a major pain. Plus the 6th and 12th wire have a cylinder identification sensor. And if you thought the passenger side plugs was easy try getting to the driver's side rear two plugs.

The problem is the cylinder identification sensor installed onto 2 plug wires. What does this sensor actually do? Instead of what many people thinking, this sensor isn't for the ignition section of the DME (that's the crankshaft position sensor) but it's for the fuel injection section.
The M70 uses dual Bosch Motronice v1.2 semi-sequential fuel injection systems. The 12 injectors are running in 4 sets of 3 injectors, meaning that a set of 3 injectors is opened and closed simultaneously. So one bank one 1-3-5 are triggered, and after that 2-4-6. On bank two 7-9-11 and 8-10-12. For this system, the computer must know when to fire which group of injectors. Simply said: when the DME notices that #6 is firing, the injector group 1-3-5 is triggered to inject fuel.


Here is the link to their page for some more help and look under spark plug wires (v12). (http://bmwe32.masscom.net/)

Get one from a junk yard.

...and the wires and cap were pulled. There was supposed to be a 735 there, too, but it wasn't where the Bimmers/German cars are supposed to be, and they weren't willing to help me find it, despite the rolling of eyes.

But, I will keep looking.

just so you know -- we found an answer to this problem. As long as your wires are o.k., you can rebuild them by buying the ends and new crimpy guys -- we rebuilt a wire and it worked great. These wires have a SOLID wire core (not the silicone/powdery type) that have resistance throughout the wire. The ends of the BMW wires are where all the resistance is. The resistance is stated in the parts description.

...and the wires and cap were pulled. There was supposed to be a 735 there, too, but it wasn't where the Bimmers/German cars are supposed to be, and they weren't willing to help me find it, despite the rolling of eyes.

But, I will keep looking.