epowers777

I made the mistake of moving that screw that stick up in between flap and fuel distributor. I got a mb manual online and cant figure it out. I fixed the vacuum leak and got to adjust the fuel. Please help

ps2cho

The mixture adjustment device or the small circular...button? that affects the height of the sensor plate?

epowers777

Thats what im guessing it does. It takes an Allen key to adjust.

ps2cho

That is the mixture unit.
Here is a good link to set it.

http://www.landiss.com/mixture.htm

Put it at between 40-50% and just leave it alone!!

epowers777

Well for an ubdate Im a dummy. I turned the screw so much I couldnt even start the car. Well after a battery charger a million turns and a hot starter I quit and got an idea. I called the wife and had her start it. While starting I pushed on the P flap an WAM she started. thank you mercedes!!! I CAREFULLY turned the screw while forceing it to idle. Slowely I lifted my finger to close flap while the fuel mixeture changed. Took about 25 minutes. It also died a few times. Finally got it to ideal on its own. Had wife shut car off then start. Took a few 1/4 turns to get it to start on its own. DONT turn to much u will flud her out.........At first I thought it was something elso so I check the spark plugs and they were sopping wet. Also had good spark and thats when the idea came. ( Upper half for people who need help and made my bad decision)


Ok heres were Im at need help!!!....
Did 2 checks 2500rpm
First 68% @ 13.5v @4.1v to 4.5v = average 4.3
(leaned died so richened 1/4 turn)
second 75% @ 13.5v @3.1v to 3.7v=average 3.4

Idle

First 93% @ 13.5v @ .9v to 1.0 = average .9 ( bounced slow)

Second 93% @ 13.5v @ .9v to 1.0 = average .9 ( bounced faster)

Theres the specs what do I do from there Ps2cho
Thanks so much for your help!

epowers777

Came home late tonight and no start. Back to the drawing board. hopefully it just needs gas.

epowers777

anybody got any tips for me?

ps2cho

Easiest way to fix this will to have your wife hold the accelerator down a bit and crank the car while you twist the mixture device until she starts. Remember a full turn is the difference between start and no start...so go 1/4 at a time and wait a few seconds before doing another.

epowers777

Im not to worried about getting it started what I need help with is the percentages I have given above. Well a high percentage means what???? Am I running to rich or to lean? So is 0% lean and 100% rich or the other way around? I havent had time to work on it but hopefully soon. If I know im lean or rich it will really help me thanks!!

ps2cho

Well, according to technical documents, the mixture or duty cycle is not supposed to affect how rich or lean the mixture is. The % fluctuates from rich to lean and that is indicative of the oxygen sensor working in tandem with the system in a closed-loop state. The duty cycle, when set correctly, allows the fullest range so the system can adjust accordingly. When the duty cycle is set to 50%, it allows the system to compensate 50% rich and 50% lean. If it was set at 70%, it now only allows a 30% increase in richness, but now a 70% compensation to lean. Get it? It is not supposed to be a way to manually set the mixture -- only to create a range for the system.

There is a debate whether or not the mixture changes things -- but in my experience and others' too, it does seem to affect the mixture to some extent.

What you really need is an CO2 tester to get the best information. The alternative to this is to use a DMM to read what the O2 sensor is finding. Probe the two cables (underneath passenger seat) and it will flucutate between 0 and 1v. 1v means rich, 0 means lean so you want an average somewhere around .5v.

The last way, and the quickest, is to just set it at 50% and let the system adjust itself as this is the way the system was designed. But as I said above, experience and technical specs don't always hold hands.

The numbers you posted are from what? The X11 and the EHA? I'm a little confused. Either way, they are too far out of range especially if that 93% is true!
EDIT: Oh okay I think I get what you are doing now. It is redundant to use both the % and voltage as they show the same thing. The X11 connector uses a 0-13.5v (IIRC) range. 14.3v indicates lean the way that you are doing it, and 0v shows rich. Take the voltage you get, and subtract it from 14.3 and you get the % you got...See? So its easier just to use the % as both numbers mean the same thing.

Hopefully this helps.
Goodluck!

epowers777

The o2 sensor I put in is new ( 7 months) It has 2 white wires and 1 black wire. Which ones do I probe. I wonder if I reversed the 2 white wires ( had to cut it in)

Ok lets look at the math numbers.

This is the old math problem I was using from that article u sent me.......duty cycle=[1-(v{pin4}/V{max}]x100%

What your saying to do..........
2500rpm check
first.......4.3v-14.3v=10%
Second..........3.4v-14.3v=10.9%

idle........
.9v-14.3v=13.4%

So if 0%is rich and 14.3 is lean Im running way to lean which is probably y it won start when it cooled down SOOO i need to be at 7.2% to be at 50 percent????

Also did you detach a purge line?

epowers777

Got her started turned clock wise 1/2 turn started right up got a reading of 6.8v which is 6.6% BUT that wasnt warmed up so just an update. Also is it suppose to cycle volts at idle or only at 2500rpms?

ps2cho

The voltage/% should fluctuate all the time. If it doesn't you are not running in closed loop for either 2 reasons 1: Not warmed up. 2: O2 sensor possibly bad.

I'm not sure about the purge line...I have never removed it. Concentrate on getting her up and running, wait til she warms up then keep adjusting it til you get 50%. Rich or lean doesn't matter in this case...just get 50%

Your math is wrong here, but I also wasn't too clear either.
The correct method (I am assuming because you don't have a % function on your DMM) would be this:
4.3v/13.6v = 0.32.
then take 1.0 - the above to make it into a percentage:
1.0-0.32 = 68%

4.3v is 32% lean and 68% rich. Make sense? You aren't too far off. Just turn that anticlockwise about 1/6 of a turn if you haven't touched it since and that should bring you to 50%.

To make it easy... 13.6v / 2 = 6.8v (50%) <--- this is your target # to be by within a 10% margin so +-1.36v

epowers777

Sorry it took so long to reply my internet was down........ I got her running and seems to be running reall good. At idle it idle great and at drive it feels like theres a missfire but Im sure its the tranny mounts. Psycho trying changing your fuel check valve. It seemed to fix alot of my problems in idling.
Ok heres the specs at idle I got a 42% and at 2500rpms I got 45%. ......Is that good??? The only problem is my cycle isnt a close loop like the paper says only 3 ten thousands of a movie example 4.5v 4.6v 4.7v So you pick 4.6v and then do your math. Mine moves 5 times does that mean my o2 is bad????