Join Date: Oct 2013
Location: Maryville, Illinois
strange 850 turbo problems
My 1996 850 turbo wagon with a b5234t engine is doing strange things. When started, it will idle at normal rpms, but the temperature gauge goes to mid-range (normal operating temperature) as soon as started. After idling 3 to 4 minutes, the temperature goes to the bottom peg (cold), and the engine revvs to 3000-3500 rpm. If the idle air valve electrical connection is unplugged, the idle returns to normal. It will go back to the high speed when plugged in. There does not appear to be any air leaks in the intake system. If the vehicle is turned off, it will not restart until it is stone cold...3 to 4 hours. There are no codes being shown.
I suspect the problem is not in the idle air valve, but in another electrical area. Edmonds does not have wiring diagrams showing the engine control systems. Any suggestions would be greatly appreciated. Thanks.