Hello I have a 96 456gt and I have the same problem as many of you. My left ecu turns on and off now and then. But sometimes mine only runs on 6 cyl. when it happens. Today when it happend I just disconected the ecu, and suddently the 6 dead syl. fired up again and the engine seam to run perfect??? I drove 20-25 minuts back home without any trouble!?!? (I think!?!?) Can any one tell me if this is normal and safe? Can I damage the engine runing without the exhaust temp. ecu? What does the ecu do besides cheking exhaut temp? Everything seams fine to me, but I dont know. Can anyone enlighten me pls. Regards Paul
Under what conditions did you disconnect it? Did you have the car off? Battery disconnected? I recently had a problem where my "95 456GT suddenly developed a check engine light accompanied by loss of power. The car would operate as normal until greater than 1/4 throttle, then would pop and fuss and generally run like crap. During diagnosis I discovered the common coolant hose issue in the "V" of the engine. I removed the intake manifold to fix the hose, cleaned the contacts of all the sensors I could see and cleaned the MAFs - they were quite dirty. Once the car was put back together, the problem disappeared. I suspect you may be in the same boat here. I too get check engine lights periodically - 1-6 has been locked in for several days now... Why do you think the ECU is losing power? Or is it just that bank?
These issues are often because of sensors (obviously deanhalter experienced a dirty maf) sometimes because of oxygen sensors or even temp sensor (ecu considers engine is cold while it should be hot, or opposite, etc). To clean them and check the quality of connectors must be done every two years at least. good luck
The engine was runing on the right bank of syl. when I disconected the left bank ecu and te engine left bank fired up again. With the engine running on all 12 I then tried to conect the ecu again and emediatly the left bank cut out..... Before that I had tried to restart, and cut batery etc to "reset" the car with no sucsess. Regards Paul
In 456,if work only one bank and slow down warning light on,maybe the cat.temperture ECU or the thermocouple failure.The engine ecu will retard the engine timing when the cat.temp.ecu send the signal is cat.temp too high.Besides,you must check the fuel pressure in both bank is at least 3 bar at idle and keep at 4000 rpm.The ignition system needs to check the spark plug to make sure that is ok.The ignition system and fuel system problem can cause the engine ecu retard the engine timing and inject more fuel to cool down the catalytic convertor.If the temperature too high,you still to dive is very dangerous.
