CIS-E: Function of EHA and fuel distributor
 

I can't start my 1987 190E 2,3 (W201 engine 102.985).

Ignition and fuel pressure seems OK (strong spark and specified flow through pressure regulator), Voltage inputs to ECU are also OK, Fuel Pump Relay and OVP seem to function correctly.

Pressure at cold start valve output of fuel distributor seems OK (the valve can produce a fine spray), but the 4 injector outputs have very little pressure, i.e. fuel flows proportional to the posistion of the air mass sensor (from none to some milliliters per second). Applying 20 mA current through the EHA in either direction hans no (or at least not a significant) influence on the flow rate.

Is it normal, that fuel to injectors are not under pressure, and that EHA current has so little effect on the flow?

Any other suggestions?

Check you AFM to Throttle body boot. If the AFM plate does not get sucked down enough due to a leak in the boot, or the AFM plate being out of calibration than no fuel will flow, well a tiny bit but more when the plate moves down. Any easy check to see if it is AFM related is to have someone look at the AFM plate when you are cranking to see how it moves. Then have them push it down ever so slightly to see if it will start. BY slightly I mean 1mm or 2.

Not sure what you are saying - note the injectors have check valves that will not permit fuel flow below about 40 odd psi in the injector lines. If there is any injector output, secondary pressure is at least that.

Steve

The AFM plate does open a few millimeters when cranking. And I did try to push the plate downwards, but still without any life from the engine.

Thanks.

I will try (when it stops raining) to take out the injectors, to see if they have any output at all.

Jens

I would take a hard look at the idle air management system. You may be barking up the wrong tree. Make sure the u shaped hose is attached to the manifold and the idle air valve. It is under the manifold and can cause the problem you indicate. Also try running 12 volts directly to the idle air valve and try to start the car. I just went through this on an 87 2.3

Good luck