Cleaning the TB is a great place to start. Also check the TPS. Make sure you have a multi-meter handy as this will prove to be very valuable when checking the TPS.Use Fuel injection spray cleaner and a toothbrush to clean out all deposits on the bore and butterfly (dont forget the vacuum ports on the top inside of the TB). DO NOT USE CHOKE AND CARB CLEANER!!!!! Another thing, I had a problem getting a gasket locally so I got a good quality gasket material and made my own.Use spray injection cleaner. I got some at Advance auto which was specially formulated to clean TBs. ALso, Take the TPS off when you clean the TB to prevent damage. With you multi-meter check for continuity abd resistance on the pins. It will become evident what the switch positions do and how this works if you are careful and disassemble the TPS-It is easily done. Clean the contacts ( I used contact cleaner)and make sure that you get accurate resistance and continuity reading from you meter. FOLLOW YOUR BENTLEY MANUAL TOTALLY on adjusting the TPS. It is very easily done. Also you might want to check the Idle Air Control Valve to see if its clean and that it works properly-Again, follow the Bentley manual for testing proceedures. The whole job should take you about 2.5-3hrs at the most. Well worth it as this is a maintainence item that gets missed.Lastly, you might want to check the condition of the bellows on the TB intake (exit side of AMM) for the TB. Check for cracks etc. AS many complaints as I have with the Bentley manual, it is great for electrical checks and such. I did exactly what you will be doing over the weekend and it was very easy.
--
1991 245 130k-(Volvo number 4)