Bret,
While the tests in the referenced page are valid to find high-resistance grounds, some cautions should be noted -- not all digital multimeters are suitable for making low resistance tests below 1.0 Ohm, and there have been suitable analog meters made by HP, Fluke, and other mfrs for at least 60 years ... called milliohmmeters or Wheatstone Bridges that are perfectly suited for this type of low resistance testing! High-resistance grounds are a valid concern, but they are pretty rare ... much more rare than silver Permatune failures in summertime temps! There will usually be intermittent starter engagement issues if there is a high-resistance ground cable problem! Lonnie's usage of the term 'Ground Loop Problem' is highly unusual, and not really appropriate for discussions of DC power circuits!
Lonnie has never, to my knowledge, I repeat,
NEVER acknowledged a heat problem with their units, and I know of one case where they tested a comfirmed intermittent 'silver-cased PermaDevil' 3-pin Permatune and sent it back tagged 'No Trouble Found' ... it was later sent to me for further evaluation. The car from which the silver Permatune came had no problems due to high-resistance grounds! I am convinced that Permatune technicians never test units returned from the field under heat lamps or at elevated temperatures! Lonnie used to post on this board, and I challenged him to address the temperature problems many, many Pelicans have had with the silver permatunes ... his response was that their 'lab' had an autoclave!!!
I tested the intermittent unit under heat lamps during an extended bench test while monitoring the case temperature adjacent to the Permatune emblem. Over several hours ... I moved the pair of heat lamps closer and further away while monitoring for missing output pulses with a pulse error detector. In every case, when the alarm went off and missing pulse failures were happening ... the case temperatue was above 190°F -- a not-so-unusual temperature under the hood of a 911 engine in the summertime!
Does the PO still have the Bosch CDI unit? Is he willing to find it and give it to you so can return it to its' rightful place in your car?
What I suggest at this point is the following:
1. I would emphasize that the body-to-transaxle ground strap probably does need to be checked ... and then removed and cleaned with a wire brush at both ends [mounting location at body and transaxle, too] ...
2. The magnetic pickup assembly should have a resistance of 600 Ohms, +/- 10% at room temperature. Disconnect 6-pin cable from CDI unit and measure the resistance back through the green coax cable towards the distributor and pickup coil with digital multimeter set on 2K Ohms range. Leave test leads connected and set multimeter to 20 Volt AC range ... crank over engine and look for 1 - 3 Volt trigger signal. NAPA sells a replacement pickup assembly for around $30 ... if your tests are indicative of a bad pickup coil.
http://www.napaonline.com/masterpages/NOLMaster.aspx?PageId=470&LineCode=BA&PartNumber=1800144&Description=Distributor+Pick-Up+Assy
The electrical connections in your engine compartment go through a heat cycle every time your car is used. Expansion and contraction occurs every time, and any corrosion present may cause a change in the connection when the connectors cool down from normal operating temperatures!
My basic position is still the same as that posted in the following thread ... regarding cleaning electrical connections!
http://forums.pelicanparts.com/showthread.php?threadid=158541