It is technical, how to use a (V) volt meter to measure I (current). The resistance of the EHA is probably so high that you have no resolution on the voltage change. It could also be controlled voltage so the current changes but the voltage is held constant.

You need a 1 or 10 ohm series resistor I wouldn't encourage you to do it. Are you saying you meter doesn't have an (DCA) direct current amps scale or (DCMA) milliamps:less than one amp? It might just be labeled without the DC.

If so ~20 - 30$ will buy a good enough multimeter at Homedepot or Radio Shack. Try asking the sales guy for a meter that will measure just a few miliamps. They will at least be able to show you where on the meter to look for the current scales.

Covered you on the other measage too. You might want to start a new post to bet braoder help on how to measure, adjust and balance the the EHA and mix.

The slow rise means the two are not centered on their control range. what do you mean by even engine flow? Smooth rather than rough or surging of surching? It is helpful to say where the idle ended, high means you are rich and low means you are lean.

Getting to the balance takes some imagination and perception. When the mix is in the 60's the EHA needs to go to where it pulls the mix to 50%. ie., Starting at 60%, ( i think that is lean so EHA is set too rich) go anothe 1/8 cw. Now which way does the % go? If higher like 70%: wrong way. Go back 1/4 ccw (now 1/8 ccw from where you started.) % should go below 60% and you are going the right way.

When you get close, the voltage and rpm will not ramp and peg or ramp and quickly start the ramp again. It will hunt, jump around, in the same voltage area, at 2000 the voltage should be the middle of idle movement and not off outside the idle range. The only way you can get ther is to get the EHA current to zero +- just a little. That means centered at zero. And, The % will allow you to adjust it to the same % at both idle and 2000.

Stay in there.

Current! I dun know
 

Yes I shall keep on trying, It has been said you cant teach an ol dowg new trics, But I say ya can jest takes longer.
Well I had such high reading at the Eha that I put the meter down said to my self self must be somptin wrong.
Cousin Kennith has a digital unit I will use his as for mine I tried to get pics of it but my camera will not focus in on the tiny thing. It dose have MA 0.5,10,250 and 1.5 volts dc and ac scale but I cant read any # below 0.

As for the flow of the eng. what I was trying to say, was the eng. got very smooth and slow rhythmic search at one volt rise and fall back to start, say 4.4 to 5.4.
Went back to Shreveport today and started the trip with the eha unplugged was hard to get it to take the fuel, plugged in and it took the fuel ran very well till we started home it shuttered two or three times then cleared up,Though I did notice at 55 to 60 mph on cruse control it had a shutter took it off and it was fine tested this several times same result,so a smoke test will be used to see if I have another air leek.
By the By I have a sight for you look up air flow meter pot my name look into the two sights cool.:idea2:

I'll look you up, you are notorious? See how much fun we are having?

Did you do the smoke? I've never done that, can you see the smoke being sucked into the leak?? I'll assume you still have to adjust the EHA:

1 "eng. got very smooth and slow rhythmic search at one volt rise and fall back to start, say 4.4 to 5.4." Wow, sounds like you nailed the idle mix adjustment. But, when you raise the rpm to 2000 (pull the plug to the ICV will get you close enough), does the voltage stay right in the middle of that range. Or, does it move off to one side and stabalize not at 5V? These two readings along with idle rpm tell you how well the EHA is set. I'm guessing your 2000 is not at 5.

I'll assume you need the EHA current reading and once you get EHA I right and the two mix V settings right, the car should run great. If not you have eliminated a lot got the fuel adjustment right on and know a lot more about what is not wrong.

2 "Well I had such high reading at the Eha that I put the meter down said to my self self must be somptin wrong." What was the reading??? We need #'s...

3 "It dose have MA 0.5,10,250 and 1.5 volts dc and ac scale but I cant read any # below 0." Cool, that is what you need. You need the 0.5MA and 100ma scales. .5 is close to 0 but if you have 6 to 8 ma at the EHA, the 10ma scale is needed. The 100 is needed to check the polarity and connections with ignition on eng off.

I'm suspecting you don't know how to use an amp meter. If so, read the next two paragraphs carefully: It is not connected like a volt meter:you have to open the circuit. It this case just pul the plug to expose the pins and connectors. The meter goes in one side of the circuit like a switch to a light, in 'series'. It jumpers, closes the circuit on one side, going between, the plug on the EHA and the socket that connects to that pin.

Get a jumper wire with allegator clips on each end, or rig one with a small wire like sprinkler or bell wire: paper clip size wire. Strip the ends about an inch. Pull the connector from the EHA. Wrap one end of the wire around the pin closest to you on the back of the EHA. Get a few turns on it to hold it on and give a certain connection. put the other end into the connector that would go to that pin: fold the end back on itself at least once so it holds itself securely in the socket. That makes one side of the circuit.

Now connect the meter leads the same way: one lead going to the pin and one going to the socket. The meter is now in series on one side of the EHA, the other side is jumpered and you are ready to measure.

Be careful not to let the wires touch metal. They are hot and connecting to ground may damage something!!! The meter is technically a short the EHA will get the same current and opperated normally with the meter in series.

To check your connections, Turn on the ignition and you get 25 or 75ma. If it pegs the needle left, polarity needs to be reversed. Just swap the connections at the meter. This is now + current. Up scale the meter to see the reading. Start the car and you should be measuring the EHA current for the temp of the engine. Get it warmed up and it should prop to a few ma. If it pegs south, the current is now negative, reverse the meter connections and down scale to see what you have and write it down.

Adjust the EHA screw 1/8 turn, Air Mix will now be off for the new amount of gas and you need adjustment the mix. Here is a trick: write down the idle and 2000 numbers. They should be different by how much of a change you made.

And, You may have missed this: the mix ratio at 2000 needs to stay right in the middle of the idle range. I'm sure yours won't be, ie 3-4 at idle, 6-7 at 2000. adjust to get back to 5+-.5. And when you are close, the 2000 reading will be very stable like 5+-.1, fun. Last the idle needs end up at 650. Too high and the mix is too rich, too low, guess. If you can't get them to 5 with smooth, 650 idle, say the idle is high, it means too rich EHA, low idle means too lean EHA.

Your turn,

Ok dude the no. are on another sight remember the ones I told you to check out? well I started another thread to pull more info in from the authors of those sights.I did allot of testing today and have a great deal of #s down in that sight, BUT I did not test the EHA in series,never even gave that a thought.SOOOO I will test more tomorrow and give up those to ya.j-n-t

Air flow meter readings by me

Eha Readings
 

Well I think the mark was finally hit,I have -0.0 to +0.01 at idle and holds the same threw 2000, so we should be just in the ok doo kay spot.
The power is much greater and the fuel mileage is better too!
Fuel mileage has increased by 1.6 mpg. to a respectable 19.5 mixed driving.
The next task is the potentiometer,and fine adjustment of this unit. POT. has been installed and improvement is noticeable though I am not ready to voice a complete opinion of the job, I feel the need to investigate the fine adjustments, before I say I am happy, As always I will keep you all informed of the results.jNT:D

Well it has bean almost a year from my last post on the subject of the intake system on this 420sel and I am sorry to report that not all of my work was successful, the wet intake chamber is wet as it was in the start of the work, though I have acquired another car (190E 2.6) it has two troubles, one wet intake and poor restart after warmed. I may have a little trouble with the fuel pressure valve, will have to check all of that system though it gets 25mpg hw, and 20.6 in town, I'm happy just need to do the fine tune. JNT.

latest up date on the varnish in the intake plenum, the real cause of the varnish in the system,is due to fuel drip from the fuel distribution block. Apparently the O ring at the base of the unit is not sealing the system, and dripping fuel into the plenum. JNT