Sorry for the dramatic subject, but I'm at wit's end. Any help would be *greatly* appreciated.

CAR: 1988 German-model 190E 2.0 Sport. 85k miles, US Emissions Pkg, CIS and all the same engine electricals as the US 2.3

SYMPTOMS: Surging/Stalling after cold start. Severe engine hesitation under low-rpm load following start (hot or cold). Injectors do not shut off on deceleration with any computer I've tried.

TESTED/REPLACED: New O2 sensor. New plugs. New cap & rotor. Wires OK. New Fuel Injector Seals. No vacuum leaks. New over-voltage relay (working). Fuel Pressure Regulator OK. Aux Air Slider Valve appears to be OK (9 Ohm Resistance). O2 voltage at idle = .56, full throttle 0.93, cruising 0.15. Coolant Temp Sensor OK. Fuel pressure OK. Engine running better than ever (9.6s 0-60 runs w/auto) and getting better mileage than ever (27hwy, 23 city).

REMAINS IN QUESTION: Electro-hydraulic Actuator, Engine Computer.

STRANGE THINGS: Voltage across Terminal 3 & Ground fluctuates around 6V with the throttle slightly pressed. Fully released (when switch is not actuated), voltage is constant 12.2V under *all* conditions. This did not happen with donor computer I substituted in, but engine still surged. Computer was from an '84, i.e. not an exact match. Is this 12.2V thing a "limp mode"?

When I unplugged the EHA, there was *no* difference in idle.

When the Aux Air Valve is unplugged, idle is glass smooth at 1200rpm. (750 with it plugged in, surging slightly when warm, massively when cold. Idle sometimes jumps to 1100 and stays there when warm).

Currecnt to EHA (with EHA disconnected) following cold or hot starts is 0.13A.

The car has spent 4 weeks total in 3 different shops (including the Dealership), and we're all stumped. I'm hesitant to spend any more money, but my next step is to replace the computer and the EHA. But will it help?!

REWARD: If you help me, I will love you forever, say nice things about you forever, and more importantly, not post any more long messages.

[This message has been edited by 190E 2.0 Jason (edited 05-09-2000).]