Chrysler Repair: 87 2.2L turbo dies after 10 min., 42 code, hall effect sensors, spark coil

Question
I have an 87 Lebaron 2.2 turbo that runs fine for 10-15 minutes then dies.I have no voltage to
the coil, injectors or fuel pump. After it sits it will restart with same symptoms. The computer had an ASD code in it. I traced the wires back to the power module on a computer,all items are fed by the same output from the power module. The ASD relay is also made into the power module.
I have tried 2 reman units from 1 parts store that would not even start the car. Just tried another brand with the same results as the original power module. I also installed a new fuel pump. Any other suggestions would be greatly appreciated.Thank you.
Paul

Answer
P.S. I thought of another way of testing whether the issue is your ASD circuit or your hall effect sensors in the distributor that are causing the die off. Why not jumper a 12v supply from the + post of the battery clamp to the + post of the spark coil and then drive it for long enough to see if it fails as it typically is doing. If it does, then the issue is indeed the sensors, it it doesn't then the code is right and the ASD circuit is quitting. Just remember to remove the jumper after the test drive so as not to run down the battery. This jumper is temporary, for test purposes only, and it will cause the spark, pump and injectors to get power regardless of whether the ASD is working or not.
Roland






Hi Paul,
I have a couple of thoughts. The way the engine runs for a few minutes and then dies is more consistent with the breakdown of one of the hall effect sensors in the distributor, but that would cause an 11 or 54 code. So I would opt to replace those sensors only if the tests for the ASD circuit proved to "pass".
I am limited a bit by not having a troubleshooting manual for the '85 non-turbo version of the 2.2L but it appears to me that the ASD part of the systems are identical to your '87. I am also limited by the fact that the wiring diagrams in those years treat the ASD as a 'black box' part of the module so I can't really understand the wires except for what is shown in the manual and maybe by reference to wire color in an '89 manual when the ASD was externalized and the controllers were unitized into a single module (SMEC). The electrical engineers at Chrysler are consistent in the assignment of wire colors, thankfully.
In any case for a code 42 the troubleshoot manual says to pull the red plug from the logic module, turn the ignition switch to the run position and check the voltage on pin 17 of the plug (hold the plug vertically with the tab on the top,facing left; 17 will be the 5th from the top on the right side column). It should read within one volt of battery voltage. If that voltage is o.k. it says to replace the logic module. If the voltage is 0-1V then pull the 12 pin connector from the power module (it doesn't say to but I would  replace the red plug in the logic module before doing this test) and turn the ignition to run, and then measure the voltage on pin 5 of the power module's 12 pin socket (not the plug). Pin 5 in on the left side (5th from the top) if the orientation has the double arch at the top. Again the reading should be within one volt of battery voltage. If the voltage is at that level, then check for a poor/open connection between the pin #5 of the plug and the coil/injectors/fuel pump. Also make sure that terminal of pin 12 of the plug is not spread apart so it can't make contact with the pin of the socket. If the voltage on pin 5 of the 12 pin socket is 0-1V then replace the power module.
One other observation: The manual doestn't say so, but based on how these ASD circuits work on the SMEC set up, I would expect that the 12V to the coil. etc should be there for about 1 second when you turn the ignition to run, but then disappear until you start cranking the engine. The trouble shooting manual doesn't address the time dependence of the voltage measurements that it suggests that you make. Also, I would be inclined to do all the above measurement when the system has failed, not when it is o.k. Otherwise you will not be testing it when something is wrong.
If it seems to pass the tests, then maybe trying a replacement of the distributor sensors in in order.
I am a bit surprised at the meager documentation of this system, it was improved in post'87 manuals. Also, be aware that the shift to the SMEC set-up occured in the middle of the '87 model year and you evidentally have the early '87.
So let me know if this is of any help.
Roland