I was driving my 89 300ce around 45 miles/hr and slowing down to the stop light. I stopped , the engine cut off and all the lights came on. I started the engine again and drove another 100 miles (stop and go traffic) without any problem. This was the first time happened to me. Any idea? Should I take it to the shop and check it out or do some DIY myself?

Very similar to problems I am having with my 89 190e. Turns out I had no voltage going to the idle air control valve. Still trying to track down where the voltage is lost but have unplugged to ICV and it has not done it since. Might want to try that until you can figure out if you have voltage to the ICV or not.

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89 190E
2.6L
Arctic white
Grey leather
Sunroof
Pirelli P400 rubber
Smoked corners

Hi 190e, How can I find out the voltage of ICV? Where is ICV?

Not sure on the 300 but the 190 the ICV is right in front of the fuel tower. You can tell it by the two rubber hoses running from the manifold to the intake.

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89 190E
2.6L
Arctic white
Grey leather
Sunroof
Pirelli P400 rubber
Smoked corners

A combination of old, hard hoses and a dirty ICV will do this -- valve closes to slow the car down, then fails to open as the rpms drop, causing a quiet stall -- engine just quits turning, no shaking, etc.

Clean the valve by filling with carb cleaner, covering the holes, and shaking for 15 sec, then dump the solvent, until it stays clear. This will take a while, probably tons of residue in there.

If the idle control hoses are not fairly soft, replace them.

If you get occasional stalls while just driving, replace the fuel pump relay.

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Thank you very much. I will do that ASAP.

I took out the ICV this afternoon, it looked clean and I cleaned it again anyway. I pray the problem won't come back.

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89 300 CE

After another 400 or so miles. It happened again. I restarted engine and went home OK. What is the next step? Fuel pump relay? Thanks.

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89 300 CE

That would be my guess.

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89 190E
2.6L
Arctic white
Grey leather
Sunroof
Pirelli P400 rubber
Smoked corners

I once had that same problem with my '88 260e. It started as an occasional stall and became much worse over the course of several months. The problem turned out to be the airflow sensor pot mounted on the front of the airflow sensor. It wears out with time and causes the problem you describe, especially at idle and when coasting to a stop. Try a search on "airflow sensor pot".

The Bosch part is available from Olyparts.com. It is kind of sensitive to replace but not horribly difficult.

There are other causes of stalling that should be investigated before assuming the pot is bad.

John

If it stalls while braking hard ONLY, it's the idle control valve and/or bad idle control valve hoses. If it stalls at any other time, it's most likely the fuel pump relay, unless it ONLY stalls when suddenly opening the throttle -- in that case suspect the airflow meter pot.

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Thanks all for the replay. Psfred. I didnot brake hard, just normally hit the brake, slowing down. However, they both happened when I exit from freeway. I did take you advice last time, cleaned the ICV, I touched the ICV hose, they were very hard ( I had to pressed with force). You said "Fair soft", Do you mean they are suppose as soft as heater hose? Thnaks again.

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89 300 CE

They should be as soft as heater hose if not softer. Replace them, they are surely leaking. The one from the air meter horn is easy, the one to the manifold (with the cold start valve in it) is a bear. It will run much better.

Replace all the other bits of rubber hose on the vaccum lines, too, they are all probably rock hard and leaking, or gone mushy and leaking. Replace the hose to the MAP sensor on the left fender, too.

Clean the ICV again by filling with carb cleaner, covering the holes, and shaking the carb cleaner around for 30 sec, then dump. Repeat until it's clear coming out. This will take a while a several shots of cleaner, you need to dissolve all the old gasoline residue.

That should fix it.

However, if it starts to stall while driving at open throttle, replace the fuel pump relay and have the current draw for the fuel pumps checked!

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Thank you all again.

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89 300 CE