The trip was enjoyable We drove a couple hundred miles and it performed so very well, the only thing was a slight hesitation when cold. Today I worked in the Engine bay trying my hand at getting the voltage swing to stop its large swing, It is now set on the 10 volt ac setting and the reading is bottom 5 volts swinging to 8 volts, I had a constant 3 volt swing no matter how far I leaned the system or richened the system.
Checking the #3 pin on x11 IF I am doing something wrong can any one let me know? Oh yes I almost forgot Idle had fallen to 600 so I lengthened the long rod till I got 700 to 750,tomorrow I will see if it starts in the cold.

Foot note the Eng. worked just fine after a cold start up, lengthening the long linkage rod bringing the rpm up to700 or 750 worked with out any problems,so far.
Hope every one has a safe and great new Year. j-n-t.

JNT, making progress, you got 600 idle and I passed smog and we've both learned a lot and still don't know what's right. "lengthening your rod" is a real trick, but I know exactly what you mean. Its agood way to get home but not right. DC voltage is right and a digital meter is not very usefull, a needle is helpful.
I found 2500 a good place to do the mix, get it to 50%. then check at idle. Just the opposite of the manual. This way I end up with closer to 50 at idle.
Also the vacuum is critical on mine: I found very poor results with vacuum on. The line to my EZL had no color stripes and vac all the time. The one to the purge valve has purple and black stripes and no vacuum at idle. I switched them and life is much easier. It passed smog with a 750 idle and 5* timing. I told the teck what I did and he said it must be right. I really don't think so. But the car passes.

You can check your system (and voltage readings) with X92, ign on but do not start engine. Led is on, voltage at pin 3 X11 is 70% 3.84 volts DC meaning USA non CAL, Fed, 85% is CALifornia. Open the throttle full, 20% says good full load switch, depress air flow plate: 10% is good idle switch. Important is the relativity of where these %'s are on your meter. The formula for volts is dc reading/pin 4 voltage (battery)~12.8. ie., 3.84/12.8=.30, 1-.30= .30x100=70% Fed controller. The voltage is higher with eng running maybe 6.4/13.8 would give you 50%

Hello, I did not party to much,we had Friends from Texas in and did our thing a day early so they could get back home for the big party you know how Texans are.
On to the testing,I redid everything,and put it in the DC settings and got the following. pin#4 x11 12volts, pin#3 x11, 3.2volts after the formula I get 73% I think I am pretty close to the correct settings. All testing was done key on not running. I think that once I get the rpm thing fixed I will have to try another ICV we will be set up for some enjoyable cruising.j-n-t

Are you up to checking the ratio again? Can you get the ratio near 50% at 2500 rpm? On mine the idle % falls in very close just wider.

The current is easy to measure if your meter measures current. Some multimeters don't have a current capability. If so the meter leads go between either (but just one side) post and the corresponding socket. That is in series with one terminal. The other post and socket need to be jumpered (connected)

Try to re-explain that,you lost me!

OK but check this out too, Search on patrick_mb to see his two threads on M103 W126 part thottle mixture adjustment. He did a great job of explaining what to check and measure the mix. He also explains what you do with the EHA current.

He explains it a little differently and that helps me alot. He describes going too far rich and too far lean and watching the O2 sensor output while driving. I've watched the ratio but not the sensor.

What I was getting into was how to measure the current at the EHA. To do it your meter needs a current range and I just realized I have a clamping amp meter attachment for my cheap radio shack multimeter. The connector in on the gas distributor drivers side back corner. Black plastic thing with a two wire connector that pulls off towards the rear. With a clamp on, you don't need to rig up a way to get into the circuit to measure current.

Basically you open one of the two connections and the meter remakes the connection. I used some banana plug leads. Just find a way to connect one side with a jumper and connect your meter bewteen the other two. Choose 1Amp range first for the .75 A at Ignition switch on, then down range to see when you start the engine and want to see the +-.1A

I had to clean the gutters today (yes dear) so I didn't get a chance to duplicate what patrick-mb did.

OK, I spent some time today trying to do the job on the % of on off ratio, Static gave me 3.2 and 12v. at pin 5 eaquals 73% to get closer to 70% I should fatten up the fuel is that the correct direction?

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Ok I am back took another look at things,static ,I got 3.4, then 12volts, ok I pushed the plate down and got 9.4,when i released the plate I got 6.4 so by the way I also heard the plate scratch the horn as it came back up so I must have some work to do in the adjustment in that area,but how?I will or I suppose repairer so that it flows freely must happen be fore any other work can go on? I eagerly await the how to's. j-n-t

HI I am back, tried to set the fuel at 2500 my reading was 71% at idle and 85% at 2500 re set the fuel to get 10% dif. but it just would not take the fuel on acceleration, so I had to fatten up again. I dont know if I wish to try messing with the EHA settings.I do have a couple of fuel gauge that go up to600 pounds but I dont feel comfortable yet, maybe if I read more then I may attempt it.

You are making things too complicated or you dont really understand what you are doing. Setting these things is simple. It goes like this - Set your duty cycle at idle or at 2000 rpm. Your choice. Once it is set leave it alone. If the duty cycle varies a great deal between idle and 2000 - 2500 rpm then there is something else wrong. Things like - vacuum leak, fuel distributor, fuel pressure, EHA, airflow sensor pot and on and on. You can adjust the mixture till the cows come home nothing is going to change until you find the root cause of the problem. The ECU (engine control unit) is responsible for enriching the mixture when accelerating. It uses a signal from the air flow sensor pot. Yours is probably shot. Stop fooling with the mixture control and look for the problem in other areas. The mixture control is not the problem and adjusting it will not compensate for other problems.

You need to have a good understanding of the fuel management system for these engines and then armed with that knowledge use your observation and diagnostic skills to determine where the problem is.

To answer some of your more recent questions - yes the plate must not scrape the air horn. Must be centered properly before anything else is done. - The bolt in the center of the plate - loosten it, center the plate, then tighten it. Very simple. The fuel pressure in this system is no more than 100 psi. So your 600 psi guages will work without problems but it would be difficult to accurately read the numbers you are looking for. You need to follow the MB proceedure outlined in the service manuals for checking the pressures.

__________________
I got too many cars!! Insurance eats me alive. Dave

78 Corvette Stingray - 3k
82 242 Turbo Volvo - Manual - 270k
86 300e 5 speed manual - 210k
87 420sel - 240k
89 560sl - 78k
91 420sel - 205k
91 560sel - 85k
94 GMC Suburban - 90k
97 Harley Davidson Heritage Softail - 25k
00 GMC Silverado 1 ton 30k

dpetryk,thanks for the slap,I too felt like I was chasing my own tail,Not at all fully versed on the system I am trying to learn,the gauge would not read in small enough increments if only 100 psi so 200 is OK have some of those too.j-n-t

This sounds like your pressures are off in the opposite Lean direction. They are adjusted with the EHA and I don't think you need the guages, I'm sure I'll get corrected if wrong, but I didn't need them. you just need the current and ratio. Its not hard, just that the two compensate for each other. One is to the right of ) and the other is left by the same distance. The farther off 0, the bigger the difference in the idle and 2000 ratios; Just like what you are getting. If your EHA is lean you have to go rich on the mix. It is easy to tell If you go the wrong way, it will just get worse.

Start by measuring the current, I bet its + a few mils maybe 6 to 8 and moving +- 1. Mine was about 2. Take off the EHA module, the gas pressure, about 80lbs, will bleed quickly and spray a bit. (I have no clue why clever Germans couldn't put the adjustment on the other side so you don't have to take the module off for each adjustment.) Uncover and turn the 2mm TINY brass allen screw (careful it has no friction and its hard to know when the allen is seated. I suggest you blow the gas out of the allen and visually see how the alen is oriented.) I'm guessing CCW, 1/4 turn. I also guess 1/2 turn will be closer. Put it all back together and readjust the mixture ratio, (leaner?) Look at current I'll bet + a few miliamps. And the ratio difference will be close. Keep iterating until you get +-1ma centered on 0 current, 50% ratio, <10% difference and 700rpm idle. Mine took about 5 trys.

But it is neat when you know its right.

Ok my Friend will try today,took the car to Shreveport and it ran fine to but on the way back it stalled several times,I unplugged the icv and after several try's it Finlay went to high idle, before that it just stumbled and choked,perhaps I am going to have to buy a new Icv.well let me get started on this. j-n-t

try as I may I only have a cheep old meter and on a setting of 10 volts dc I got a reading of 3.8 volts over both of the lines one black and the other brown with black stripe, Removed the EHA and turned the allen 1/2 ccw then tryed to reset the mix ran like mud.so back into it and cw 1/4 that gave a great deal of even eng. flow once the mix was reset, but I am still getting the same voltage reading,at the EHA.
Now the lamda reading is at 4.4 to a slow rise or I should say a stedy rise to 5.4 even up and down rampping 68%
2500, was 6 volts at 56% hope I did ok.