300 E Will Not start

[Phlipper]

1988 300E:
After removing and cleaning (eraser) the airflow sensor, car would run without hunting and increase in idle. However I then adjusted the idle mixture to try and smooth out the idle- but the adjuster seems to be sticking and made the engine run very erratic.

Engine shaking then stalls.
Engine wont start again.

Owner tired goes to bed..
any thoughts are welcome.

Phil
1988 300E300 E Will Not Start

[simmo300e]

my guess is you've leaned the mixture too much. try adjusting 1/4 turn clockwise and try again. you don't need to turn much to adjust the idle mixture.

[Phlipper]

I turned the mixture (clockwise/rich) and the engine started to run but the stalled- so I think it is the mixture.

How can I index or find the sweet spot on this adjustment to begin with.
I have no idea if the mixture is cranked one way or the other..

Now batt is getting low...

[Phlipper]

Running a Bit...

it will run with the flap cracked open 1/4" only. Any variation it will stall...
Will not start with flap closed...

Still not sure where the mixture is set at...

[sbourg]

Opening the air meter flap 'tells' the fuel distriibutor there is a higher fuel demand, so it flows more fuel to the injectors. I.e., mixture is too lean to start with the flap in idle position. There is an offset adjustment for the flap, so check and make sure that is correct.

Could be your cold-start or rotary idle valve are not functioning, or you have ruptured a hose somewher in the idle air circuit.

Steve

[Phlipper]

Can you tell me where the offset adjustment for the flap would be found?

If I work the throttle linkage and the flap togeather in unison I can get the engine to rev beyond 2k. But not interested in idling...

I will check the other areas you mentioned...

Thanks for the help

[Phlipper]

OK I've tried looking at the possibilities- no luck

Does anyone think it could be related to me cleaning up the airflow sensor???

[Phlipper]

Getting desparate Now

It only runs when the flap is held partially open.

Is the flap suposed to be opened at idle under normal circumstances?
Is there an adjustment for this?

[samiam4]

THere is a proceedure in the manual to center the valve in the body. I believe this covers the screw adjustment.

Your not playing with the mixture adjustment on the tower??



Michael

[Phlipper]

/yes the mixture on the tower

And I've pulled a couple the spark plugs - very black sooty, not wet just black soot...

[samiam4]

Turning it just a 1/8-1/4 makes a difference. It's set by duty cycle with the O2 sensor. I'd try and estimate how much you have turned it... and put it back.

Michael

[Phlipper]

needle in a haystack at this point...

[sbourg]

Kinda sounds to me like you have a serious integrity problem in the intake ductwork, so that the intake is not 'sucking' its air past the airflow meter flap. I would check everything out there with a flashlight and extendible dental mirror. In particular, check the integrity of where the rubber pipe attaches between the rubber lower airflow meter plenum and the input of the rotary idle valve.

Steve

[Phlipper]

Steve, earlier today I did take off the ICV and the tube you mention did drop off. I've made sure that it is properly back in place- still no diff..

There does seem to be a lack of suck in the plenum.. i'm going in with the dental mirror.

BTW could I have the ICV installed backward? I see an arrow -which way should it be pointed?

Thanks.

[Phlipper]

Plenum looks good, tubes from ICV in good shape.
The darn thing just wont run up.

Could this all be due to mixture that far out of adjustment?