Bad Pulse Generator?
 

On a 78 911SC I'm getting no spark. I'm not getting a pulse on the 31d and 7 pin on the ignition ignitor plug. I'd like to replace the pulse generator on the distributor since it could be the problem, but mainly because the plug for it has disintegrated. The problem is I can't find it on Pelican Parts. Is this item available without buying a whole distributor?

Also, since the plug has disintegrated does it matter which wire goes in which terminal? If so, which goes where?

I believe Warren went thru the testing and wire position issue awhile ago.

I swear I did I search and didn't find anything!

I just searched again and found the bad news. I guess I'll find a new plug, get out my soldering iron, and try to fix it. :(

Could this be an opportunity for one of the enterprising folks out there to make a replacement one?

I plugged in Early_S_Man and "pulse"

one of Warrens threads in there
http://forums.pelicanparts.com/porsche-911-technical-forum/8252-no-spark.html?highlight=pulse

You mean the plug on the trigger wire (aka "green wire") or on the distributor body itself?

The wire is readily available, and not expensive. You will need to splice it into your harness though.

Tom

Here's a pic of the wires:

This is becoming a regular problem, me hitting Submit instead of Attach. Let's try again:

http://forums.pelicanparts.com/uploa...1077594860.jpg

The original brown plug is broken and only the part that plugs into the black plug is left. The wires with connectors are plugged into what remains of the brown plug.

I checked the voltage off the green and other wire and there is voltage when cranking so I guess the magnetic pickup is still good. I'll check conductivity thru wires tomorrow and hopefully find an easy fix.

You are lucky. Your harness has a plug, you can buy the piece that goes from the black plug to the distributor body.

You can find it here, listed as "Signal Cable" P/N H-602-907-01:

http://www.pelicanparts.com/catalog/shopcart/911M/POR_911M_igniti_pg6.htm

Tom

David,

The problem with the $30 replacement 'pigtail' harness is that it continues the use of the unsatisfactory green coax that deteriorates under engine compartment operating conditions!

I have recommended for years ... that a more satisfactory coax would be Teflon-insulated, such as military-grade RG-188A/U or RG-180/U, both of which are rated from -70°C to +200°C ... what I suggest is an entirely new one-piece cable from distributor to CDI unit. The coax is only about $20 for 100 feet.