Here was my original posting:

"A fellow I know called me about a problem with his '85 240. He said he had turned the ignition key to ON and then was distracted by a customer. After about 3 hours, he realized he was hearing a clicking sound from his 240. When he tried to start it, it was so flooded with gas that it was hydrolocked. The clicking sound was the fuel pump relay repeatedly clicking.

He pulled the plugs and got the gas out of the cylinders so the starter could turn the engine over. However, the engine would barely start and would die often. It would idle very poorly before it quit running. While the engine was running, he could feel the inlet hose to the fuel rail and it was pulsing in time with the clicking relay.

He tried the following: Replaced the fuel relay. There was no change. He disconnected the AMM and the engine would still not run.

What do you folks think the problem is? Is there something in the ECU which could be doing this?"

Well the owner went to a pick-and-pull and got an ECU for $30. When he swapped that into his car, the car ran perfectly. So something inside the ECU went bad and was pulsing the fuel pump relay. I assume that there was enough leakage from the older injectors to flood one or more cylinders and cause the hydrolocking problem. He was going to open the old ECU and see if he could find any visible signs of damage.

I haven't heard of an ECU going bad when it was left for a few hours with the key on but the engine not running. Has anyone else seen this happen?