Chrysler Repair: Intermittent Ignition Cutout, kevin mccabe, logic module

Question
Hello Roland

My '87 LeBaron Premium turbo was experiencing momentary ignition cutout after about a 20 minute 15 mile commute.  I checked the codes through the instrument display and got only 54 which I understood to be the Hall effect sensor in the distributor. Over the course of owning this car for about 30 months,  the temperature gauge has gradually risen from an initial reading of 7 bars to recently showing 9.  I replaced both the hall effect sensor as well as the ignition coil.  When I restarted the car,  the idle seemed improved and the temperature gauge returned to displaying 7 bars again.  This only served to delay the return of the momentary ignition cutout.  I still have no other codes but 54 and concluded the problem had to be in the computer itself.  I have now replaced the computer with a Mopar reman unit.  The vehicle is now difficult to start, requiring extended cranking and the idle now hunts very erractically varying anywhere from 2000 rpm down to 600 and will even stall.  

Either I have messed something else up in changing the computer,  or the problem which I now believe to be temperature related has nothing to do with any of the components I've replaced thus far.  But with no trouble codes showing up,  I do not know where to look next.

Thank you,

Kevin McCabe

Answer
Kevin
Have you checked the wiring to the synch pick up in the distributor. There are two separate sensors (or at least there are two separate plugs) for the '87 turbo model? The synch sensor (which is involved in the 54 code) has an orange 7.5 dc wire that is shared with the other sensor as well (from pin 23 of the red plug at the logic module), a black/light blue wire sensor ground also shared to pin 25 of the same plug, and a tan/yellow sensor synch signal to pin 17 of the blue plug at the logic module.
I haven't seen the inside of the turbo distributor, but I wonder how it differs from that of the throttle body/non-turbo hall unit, other than the extra plug. The pesistence of the 54 code points toward that injector synch sensor or its wires. If you simply replaced the logic computer and got more troubles why not re-install the original?  
Roland
PS I've read your posts at the Yahoo Club and appreciate your knowledge.