Jim Grant's Tech Tips

‘88 Dodge Caravan, Stalling
Q: Hi! I certainly hope you can help me! I have an ‘88 Caravan that stalls all the time. I just put almost $1000 into this van in 3 days, got the van back and it stalled again the next morning. The van will jerk a couple of times, like it is missing, then the RPM meter will go down to zero and then the car just shuts off. Sometimes it starts again and sometimes it doesn't and I have to be towed. I have had new MAP sensor, shut down relay, ignition coil, computer and oxygen sensor put in this van. I need to keep this van running for awhile longer. Can you help? Thanks so much....Kathie..

A: You didn’t say which engine was in your van, but from your complaint I’m willing to bet coffee that it is a 3.0 liter V-6 engine. In the distributor of your vehicle there is a Photo Optic Sensor (a.k.a. ignition module). This unit is small enough to hide in your hand, yet can easily cause a pile of towing bills. The information provided by this module allows the computer to calculate when to send spark to a spark plug and when it’s time to open a fuel injector. This information is critical to the computer, if it goes amuck the vehicle just stops doing anything useful and blocks traffic. Then it gets real fun because the electronics in the module will wake-up and act as if there was never a problem. This transpires usually after the module has had a good rest, while your vehicle’s being towed. Just to make things more interesting to the technician diagnosing, the computer will have no information to indicate that there was ever a problem. So, before any more parts are installed have your tech look closely at the Photo Optic Sensor.