If you still have no spark and you are certain of the coil, plugs, plug wires, crank sensor and PCM, that really only leaves the distributor or distributor pickup coil. The distributor pickup only costs about $30 and they do occasionally fail.

 

I've checked for spark "downstream" of the distributor and have none. Checked for spark directly from the coil lead and have none.

Battery is new and fully charged. Fuel pressure has been checked at the fuel rail and is within spec.

I noticed that the fuel pump runs constantly even after coming up to pressure. I assume there must be a pressure switch somewhere in the system which indicates to the CPU that the system is pressurized. This isn't working and I wonder if it has anything to do with my lack of spark???? Possibly the computer is not firing the plugs since it "thinks" there is no fuel?

 

Logical, so I checked the Dodge manual but I don't find one. There is a fuel level input to the pcm but no fuel pressure input. When starter is engaged and the engine is trying to start the pcm is said to be in open loop mode.

The following actions occur when starter motor is engaged.

The pcm receives input from these sensors:
battery voltage
coolant temperature
crankshaft position
intake manifold air temperature
manifold absolute pressure
throttle position
starter motor relay
camshaft position sensor (a.k.a. the distributor coil pickup)

The pcm monitors the crank sensor and if it does not receive a signal within 3 seconds it shuts off the fuel system. The pcm controls the fuel pump via the fuel pump relay.

The pcm controls the voltage to the injectors by the ASD relay. It controls sequence and pulse width to each injector by turning the ground circuit to each injector on and off. Timing is determined by the input the pcm recieves from the crank sensor.

 

In another thread with very similar symptoms it ended up being the wiring to the crank sensor AND the wire to the distributor pickup. I am sure you have read this already but just in case:

https://dodgeforum.com/forum/dodge-r...-problems.html

 

I gather from reading through the thread that your van probably has high miles. You might want to consider replacing the ignition switch as the electrical contacts may be worn.

 

There is only one other thing I can think of there was a recent thread where the problem was coming from the thermostat beside the AC unit.

 

Van is getting close to 200,000 miles on it. Any idea what I have to do to access the ignition switch, which I assume is in the steering column?

My van isn't equipped with AC, although I'm not sure if the thermostat unit you're referring to is part of the AC system or not.

 

I have not done an ignition switch replacement but it's got to be covered in Chilton. The free on-line Chilton (complements of the Michigan library system) can certainly help you with this. Here's the forum link:

https://dodgeforum.com/forum/dodge-r...e-chilton.html

There is a two-wire temperature sensor (not thermostat) located at the front of the intake manifold right next to the base of the upper radiator hose neck. It is almost completely hidden by the alternator, not the A/C compressor.

Best to remove the alternator to gain access to the sensor. The electric connector just pulls off the top of the sensor and you can remove it with a deep 13mm (I think, maybe 12mm) socket. Make sure you drain the radiator first otherwise coolant will go everywhere. Use a clean container so you may reuse the coolant if it's still good.

 

OK..first of all I want to thank everyone who contributed to this thread with their suggestions, questions and comments. The van is running!!!!

After much frustration and bewilderment the problem turned out to be a bad connection inside one of the connectors to the PCM. The red/white wire was disconnected from the pin inside the plug. Without that connection the shut down relay was always open and would not allow the PCM to put power to the coil...therefore no spark.

Don't know about you guys but to me these are the most frustrating and head scratching problems to figure out.

Finally getting the wiring diagram thanks to the above post helped tremendously.

Thanks again everyone.