You could try testing your fuel pressure.  It could be that your
pressure regulator has gone bad and your pressure is too high.  Also
want to check your grounds (on the head to the firewall) and clean them.

Hope this helps,
Ken Wilford
John 3:16
www.vanagain.com

Rick Koller wrote:

>Greetings All,
>    I have been struggling with diagnosing a high idle/stumble/stalling
>problem all day today..
>Situation: '91 carat automatic, the idle is stuck at about 1300-1500 rpms
>no change from cold to hot engine.
>recent plugs, cap, rotor. Van was running normally. Then suddenly lack of
>power, along with stumbling/stalling and high idle when not moving. Van
>can be driven but at a gradual pace, any heavy gas pedal application
>results in above symptons.
>What have I done:
>I have spare working fuel injection components and in the attempt to fix
>the van quickly, I switched potential trouble parts
>temp sensor II (new),
>idle control module ( tried several that I have including one off my other
>working van)
>idle control valve ( again several )
>throttle position switch, ( cleaned and adjusted the backup that I know
>works )
>switched ECU's
>switched AFM's
>unplugged O2 sensor when the van engine was cold or warm no difference in
>the idle
>checked Hall sensor voltage and it was right at specs ( 5 volts )
>Checked timing and it was in specs 40 degrees BFTDC @ 3000 rpms
>Van starts right up when cold, had some trouble initially restarting it
>when it was hot but this seems to have stopped.
>Any ideas out there? Bad ground somewhere perhaps, don't seem to hear any
>vacuum leaks, have pulled off varios vacuum lines. The one from the fuel
>pressur regulator had some effect of raising rpms.
>Thanks
>Rick Koller
>
>
>