Volvo Repair: 1989 Volvo 740 G.L.E. Random High Idle, volvo 740 gle, volvo 740

Question
"I have some mechanical skills, The 1989 Volvo 740 Gle has 122,00 miles on it.(B234F Engine,16 Valve.)
My car when I start it Idles Just fine, after a short time the rpm's start to rise to about 1600 rpm's. (not every time)Most of the time. A so called mechanic told me to purchase a new Idle Motor, did that, still doing the same thing, checked vacumn lines also.Any suggestions would be greatly appreciated.
Thank you
Larry"


Answer
Larry, Im surprised you still have one of those that runs.  This was a common problem that happens in these 16V motors.  Try to clean the throtle body out with carb clean and adjust it.  The Idle motor theory was great. There were issues with the fuel control unit that caused this symptom.  I havent had one of these in the shop in a while.  They all blow up and noone wants to put the money in them to fix them.  ROger