240,

please help, 1989 240 with 230f engine originally from australia.
my problem is that the jetronic computer is showing the following faults 1, fault in signal for air control valve. 2, signal fault in coolant temp sensor.
the ignition computer is showing the fault, coolent temp sender faulty.

but, the coolent sensor has been replaced and the air valve is working when tested.
I have checked all the other senders and wiring and every thing is ok
The car is reluctant to start from cold as the computer thinks the car is hot and adjust the fuel and timing to suit,also the air control is not receiving a signal to work.

even though both computers are showing that they are working and have no faults, could they be at fault?
has anybody had this happen to them or has anybody got any ideas

[Mike_Brace]

Get wiring diagram for ecu - check for contiuity from appropriate pins to sensors as it could be damaged cables. Otherwise suggests ecu faulty - try and burrow one known to be ok.
Best of luck

Mike

[Peter D]

If you are telling me that the Fuel ECU and the ignition ECU are both showing the same fault then if the new sensor was put in with thread tape then check the body of the sensor is grounded via the head. if not then both ECU with grumble. The NCTI and NCTII element of the sensor should be veru close in resistance at an given temp like 2.5K at 10 degrees down to 250 ohms at 80 degrees. What waveform have you seen on the ICV with is connected. you will not get a waveform if it is not connected. Easy way is to carefullt put a 12 bulb across the two sockets and run the engine and the bulb should look half powered as the nominal voltage is averaged at 6v. This assumes you have a two wire ICV. Regards Peter