All you need to troubleshoot you problem is your Bentley and a multimeter.
Just go through the checks described in the Bentley for your Fuel Injection
system and replace anything that is out of spec.  It sounds like your problem
could be the Air Flow Meter or the temp sender.  I have the temp senders with
o-ring for $9 or the 2.1l AFM for $110.
Hope this helps.

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