As you might have read in my earlier post I am having a problem with my van
bucking at highway speeds.  The symptoms are:
When cruising at around 70 mph van runs smooth.
If you let off of the throttle to maintain speed it starts to buck.
If you let off of the throttle completely the bucking stops.
If you press the throttle again you can go through an area where it bucks and
then you will be accelerating smoothly again.

This all started after replacing my stock muffler with an aftermarket, but
high quality, "Danske" muffler.  Now the exhaust note sounds funny like a
hiss.
After this the van wouldn't idle.  I found that the idle switch wasn't
closing when the van went back to idle (had to give the throttle linkage a
nudge to get it to move back far enough to click the switch).  I lubed and
cleaned the throttle body but it didn't help.  So I adjusted the switch
position so that when the throttle closed it clicked the switch.  Now I have
idle (a little higher than before) but after this the bucking started.

I have also replaced:
Oxygen Sensor
Coolant Temp sensor (blue)
Distributor Cap
Rotor
Spark Plug Wires
Spark Plugs (Plus 4 Platinum)

I just checked the Temp sender in the AFM and the values weren't right.  I am
going to replace this next to see if it helps.  Any ideas or similar
experiences?

Thanks,
Ken Wilford
http://www.vanagain.com
John 3:16
Phone: (856)-765-1583
Shop:   (856)-327-0027
Fax:     (856)-327-2242