Chrysler Repair: Chrysler Voyager Dying, chrysler voyager, brain box

Question
My 1991 Chrysler Voyager has a problem that nobody has been able to solve.  It has been dying for apparently no reason after about 10 minutes of running.  It only happens in warm weather.  All winter, the van ran fine.  My father helped me out by changing about 4 different modules that he thought may be the problem.  He determined these modules due to the codes taken by counting the flashing engine light before I started it.  He said that's how you can tell what is wrong.  That didn’t work.  Then we took it to a repair shop to put it on the machine, but nothing came up.  They said it was possibly the brain box (something like that - car's brain module).  My father said he checked some other problems such as spark plugs, moisture between gaskets or something like that, and catalytic converter.  He ruled out the starter because when I try to restart the van, it turns over, but it doesn't catch and start.  It takes about 10 minutes before it starts again  - sometimes longer.  It dies with no warning; the "check gauges" light goes on, and the car slows down and just turns off and I pull over to the right hand side of the road, if I am able to.  The brain box is the last hope, and that costs almost $200, so if that doesn't work I've wasted $200 on top of all the money I've wasted on the modules my Dad replaced and the test at the repair shop.  I cannot afford a new vehicle right now and I it’s very costly changing things and then still not having it work.  Any advice would be GREATLY appreciated.  Thanks.

Answer
Hi Diane,
This sounds like one of the solid state rotational sensors of the cam or crankshaft position is failing as it warms up and then recovering when it cools down. It should set a code 11 or 54 but sometimes the failure can be just enough to kill the spark but not so severe as to set a code. Have Dad show you how to test for spark and then when it happens check at that time (it still takes two people to test it,however). Or if it is that predictable have him ride with you until it fails so he can test it then. That would be how I would test it and then go on from there if you are satisfied that you do have spark and it still won't start.
Roland