IAC valve?

[superfestiva]

Hey, have a good one for ya...my cousin has a 2000 xls explorer and has the following issue that is driving him nuts...

When he is driving around with the a/c on he can't accelerate the truck beyond 2000 rpm 'cause otherwise the a/c looses speed in the fan???
In idle the a/c is ok but when he accelerates it somehow looses the fan power?
He also told me that outside odors are being felt now...

He took it to Precision Tune Auto Care and they changed the IAC which did not solve the problem but only for a day...

What can he do?
Thanks...

 

[BrooklynBay]

Did you check the mass air flow sensor? It might need to be cleaned. On a side note, I saw that you have an LPG injection system listed in your signature. Do you have a thread on the conversion?