I have a 1991 300E2.6 that has some intermittent, erratic power surges and losses. They occur at any time; idle, accelerating or cruising. It seemed like the fuel/air ratio was changing rapidly but, it only lasts for a few seconds.

Following a few posts from here I changed the over-voltage relay and the Electro-Hydraulic Actuator (EHA) but the problem remains. I disconnected the EHA and the car runs fine. No power surges or power losses; just harder to start when it's cold.

I'm guessing that I'm getting a power spike that causes the EHA to fluctuate and thus fluctuate the Fuel/Air ratio.!?!?!?! Where should I start next? The MAS control or the alternator or WHERE????????

Intruder