'89 190E Stalling (I've done my homework!)
 

Hello Guru's!

I am yet another poster who is suffering from a "mystery stalling problem" with my 1989 190E 2.6 Automatic. The car stalls at low speeds while in a decel/braking situation. It will restart again immediately and may last another hour or may last 1 min before stalling again.
The problem is evident only while the car is moving...never while in Park or Neutral in fact I have run it at engine idle for an excess of 90 mins with the car in Gear and with the emergency brake set. It never once gave any sign of a problem. As soon as I released the brake and let the car roll (with no gas or brake...just rolling while in gear) it stalls. This particular test happened while in (D)rive but I have achieved the same results in (R)everse.
As stated in my subject line, I have some homework. Here is a list of what I have done/checked/verified/tested.

1. Replaced Fuel Pump Relay
2. Replaced Air Flow Sensor Plate Position Sensor
3. Replaced Hall-Effect Sensor
4. Verified good Fuel Pressure (3.2 bars)
5. Test Idle Circuit (.55-.6 amps at idle)
6. Test Ignition System (45kv at cap)
7. Test Lambda (fluctuating at 90%)(lean)
8. Replace all plugs (gapped at .045)
9. Replace plug wires
10. Replace Cap & Rotor
11. Checked Overvoltage Protection Relay (87E to 87L - 0 ohms)
12. Checked voltage from CIS unit Pin 6 to ground (0 to 12 volts fluctuating as vehicle is rolled)

And as you may have guessed...the stalling problem remailns...So....Whats next? I have a few thoughts and just wanted to get the opinion of this board before proceeding. Should I pursue...

• Throttle Postion Switch
• Vacuum Leak (not enough vacuum to move position indicator)
• New CIS unit
• Wiring harness
• O2 Sensor

Did you ever get this resolved?

Clean the idle valve, they stick when dirty, usually as a result of bad hoses. Causes problems most when stopping abruptly rather than slowly coasting down, as the valve has more time to open.

Peter

I think the voltage fluctuation when the car is rolled is a clue worth pursuing. I'd suggest tracing that fault, paying particular attention to the various grounds. Somehow I think it's a ground problem.

Good luck and please post the final outcome.

///MikeR
'93 190 2.6 Sportline