Volvo: Volvo Torslanda High Idle, volvo torslanda, haynes manual

Question
Hi, We have a 240 Volvo Torslanda 1992/3. My husband is out at this moment trying to fix the idle which is ruuning at approx 1100rpm instead of 900rpm. I have just found your website so apologise if I dont give you enough information but will try anyway. He has been through the entire Haynes manual and replaced or clean all hoses etc. The computer is coming up with no codes. The manual suggests reducing the tickover (Simple enough) except that this model has the tickover screw welded. Any help you could give would be welcome but I understand if it's easier to wali until he comes in and is able to give you proper (Mans mechanic talk) information. Many thanks,
Terri (from the U.K.)

Answer
Terri,
I have had wire harness problems that the wires short out in the sheath and cause a high idle. I have had a bad control unit and a bad fuel injection temp sender short out. There is a idle speed motor that might be stuck or shorted due to the wire harness. Possibily even a large vacuum leak...