I'm still trying to troublshoot the IAC system in my son's 1986 240 with 2.2 LH & B230F. As mentioned in previous post, the car is a recent purchase and came with the IAC hose blanked off. We corrected the hose routing while cleaning the throttle-body for 1st time and noticed that on starting the car it revs to a high RPM and blipping the throttle off-idle temporarily drops it back down, but it immeadiatly climbs back to what it was. I have the IAC positioned with the "arrow" pointing at the intake manifold and I pulled the throttle-body off and used a meter to verify that the TPS is working. I have checked the resistance accross the IAC terminals and get 20, 21.5 and 41.5 ohms which is close to what manual says is normal. I temporarily swapped in a junk yard IAC and still see the same behaviour. When I pull the IAC plug and check voltage on running car I see 12 and 13.5 volts between outer and central socket and these readings seem to be constant and not fluctuating. Oh..and at some point the IAC and TPS connectors were switched but I'm not sure if this was from previous owner or by myself (now corrected). Does this type of behavior ring any bells? I am deeply suspicious of the cheesy wiring which I need to replace, but are there any checks to determine if the ECU is at fault?

Our other significant problem is a hesitation (almost a stall) under load. We noticed today that this gets worse as the car warms up, starting out mild and getting worse as car is driven all day. Not sure if these two things could be related. I wanted to check the O2 sensor outputs tonight but did not get this done.

Long post...sorry.

Cliff