I performed the test you requested with the following results and issues. The TPS did start at.8 and went to 4.6 at a slow full throttle.
The IAC read 9.6 ohms across the posts of the sensor.
The issues I came across was that the TPS would show the voltage even with the key OFF. The voltage would climb with the key off as well.
I found that the "check engine" light was burned out. After replacing it, I noticed that the light comes on steady when the van is started.
I also noticed that there are no warning lights being lit when the key is turned to ON.
I had a friend come by with an actron elite scanner instead of the cheap reader I have. He said that the diagnostic connector is not receiving a signal for the scanners to read.
Would any of this cause the roughness? Should I stop checking sensors and try to find this problem first?
I will add to the donation (when I figure out how) if you can continue to assist.
Sunday, September 6th, 2009 AT 8:30 AM