No spark at spark plugs...now what?
 

77 911 turbo with a 85 turbo engine won't crank. Not gettting any spark at spark plugs. The 6 pin CD unit will whine when switch is on. Could the problem be in the pickup unit in the bottom of the distributor. Any easy way to check tach, coil, cd unit, the ignition unit in the bottom of the distributor before I start plugging new parts in? Would this car have a muiltpin brain or control unit as well? Didn't see one under either seat. Thanks in advance. William.

Check under your seat for a silver box that says motronic, if it is there you have a DME and need to check your DME relay right there beside the box.

85 is the right year I just don't know if the turbo's used a Motronic computer brain.

Don. This 85/86 trubo engine appears to be a CIS Injected engine. No motronic box at all. Anyone with any advice here? Thanks

replace your cd box. the msd is a good unit

Just had the exact same problem... it was the coil.
Try a different one, or buy a new one.

Upside down on the fan housing as the factory installed it is one of the stupidist locations other than clamped onto an exhaust header imaginable.

Just turning it around to right side up and lengthening the wires is an improvement, but the heat cycles and vibration from being mounted on the motor kills brazilian or wherever they are made Bosch coils in a few years or less.

If thats not it the green coaxial signal wire is famous for going bad too.

thats my experience anyway.

Start here: http://forums.pelicanparts.com/porsche-911-technical-forum/366110-cdi-6-pin-ignition-schematic-wanted.html

Long yet informative: http://forums.pelicanparts.com/porsche-911-technical-forum/226517-history-bosch-cdi-toubleshooting-info-parts-list-changes-schematics.html

This too: http://forums.pelicanparts.com/porsche-911-technical-forum/203100-6-pin-sc-turbo-cdi-unit-repair-documentation.html

Sit at the feet of the master....

Thanks for the help. I'll look into it.