A driveability issue with my '88 245 has arisen that I would like advice or confirmation on.

Here are the symptoms:

Stumbles a bit when cold, and even after stumbling has passed their is a mild lack of power.

When warm, acceleration feels "normal", although it will occasionally hesitate or lack a bit of power.

When the warm running condition above crops up, digging deep into the throttle and asking the engine to accelerate briskly for five to seconds seems to restore throttle response for a bit. I gauge this by how much pedal travel is required to prompt a downshift from top gear to third. Yes, it is an auto trans.

Yesterday it was raining, and on leaving work the car was nearly undriveable for a mile or so. Heavy stumbling when I dipped more than a 1/8th into the throttle travel would cause the engine to feel as though it were about to stall. It finally did stall about a mile into the journey. I sat roadside for a few moments and restarted the car without problem. Once underway I dipped into the throttle rather heavily and symptoms cleared themselves. It made the rest of the ten mile journey home with only a couple instances of #2 symptom.

Sometimes the main fuel pump sounds noisier than at other times. It seems to like Lucas Fuel Additive.

So, here is what I think is going on:

While the fuel pump may be feeling a bit old, I do not blame it for the current problem. I feel that if it were causing the problems, the bout of acceleration that restores performance would not be possible.

My theory is that the AMM is playing up and getting ready to call it quits soon. The acceleration method I mentioned prior indicates to me that the fuel computer is having trouble keeping the AMM hot wire at proper temperature.

Your thoughts on the matter are appreciated.

Thanks,

Aaron