Chrysler Repair: Voyager sensor problems, coolant temp, speed sensors

Question
I have a 1990 Grand Voyager with a 3.3 V6 engine.
I have replaced various sensors, after obtaining code readouts. Tested gas and spark, getting gas and I have spark. When cold, my van will not start unless I disconnect MAP, and both sensors at throttle body. It does not have EGR sensor.
Once it starts, I then have to reconnect all sensors.
I have also replaced speed sensors and water temp sensor.
How can I troubleshoot sensors to insure they are working?
I have volt/ohm/resistance meter.
It also stalls at various times, as it makes a loud air sucking noise. After starting, if I open throttle butterfly for more gas, it stalls.
If I leave ASD disconnected, turn ignition on and reconnect, it makes a one click noise. Not sure if it is open or closed. Is this right? Hard to obtain another computer readout, since I have to disconnect 3 sensors to start. Any ideas are appreciated.

Answer
Hi Richard,
May I ask whether you have checked the egr valve to make sure that it is not sticking ajar? Try moving the valve stem, located between the round top and the body of the valve (in the flange area in between) by means of the tip of a screwdriver inserted into the slot on the stem. It should close to a dead stop via spring-action. If it is sticky spray it with WD-40 where it enters the valve body.
The various sensors require different techniques based upon their design. I would suggest that you disconnect the battery to cancel the codes (except for 12 of course) and try to start the van several times to see what the current codes if any might be. That may focus the search.
It is also possible that the wiring may be the issue rather than the sensors, so tracing from the sensor the the pcm plug for shorts/continuity maybe helpful. Do you have a wiring diagram? I can copy and postal mail you one from either the '90 car manual which is probably the same as the van.
The ASD doing 1 click is to be expected.
The coolant temp sensor should read 7,000 to 14,000 ohms when cold.
So please check out the above and give me the answers and some feedback about the results.
Roland