Yes I will I may have done this my page of numbers is full of scratch marks looks like a chicken ran north south east and half way west, I have some reading here in volts DC @ 10 and it is 6 to I cant read the others so I will heat it up in the am and make sure of the job.j-n-t

Good morning, the new test took place and DC volts are as follows.
Idle p3 average of 4 to 5.4 = 4.7 .- 13.8= 66%
2000 5.2&5.8= 5.4 -. 13.8 =59.5%

reset mix got,
Idle 58%
2000 54%
So this means I am still high on my fuel pressure need to reset the EHA again?

Hi everyone,worked on the EHA today,I went back in and gave it a turn ccw 1/8th hit the spot. New reading Idle -0.00 to + 0.00 at 2000 I have the same reading. After resetting the air mixture we have Idle 7 to 8 in slow swing this is volt setting DC 10. 2000 rpm is a steady 6.2 volts this is 48 1/2% to 54% respectively.
Now on to the potentiometer, it is not responding to adjustment.after trying to get readings and I am not getting any thing like the numbers that have been posted. I tried to move the pot. and have no change in the Idle. I removed the pot and tried to get ohm readings, this is what I have,
1&3=4.5 ohm@ RX1K
1&2= INFINITY
2&3= INFINITY
pot arm and wiper 0

200K ko eo
1&3= -165.7
2&3= - 155.1
1&2= -39.6

ko e running
1&3= -166.1
2&3= -89.5 to-130.2
1&2= -78.6 to -80.3 this is again at 200k

DC volt 10
1&3=4.8v
2&3=3.2v
1&2=.7to.8v rapid fluctuation can any of the people who have worked this item give me some hints.jnt

Not in a great place to help, I think you said a new one is on the way. sounds good.

1--/\/\/\/\/\/\/\---2 A resistor is usually drawn kinda like this to represent a long wire resistor. The wiper is then a contact that moves along the wire. lets say pin 3.
Measuring between 1 and 2 will be a constant resistance.
Measuring from 3 to either 1 or 2 will give a number that changes as you turn the wiper.

You neede to measure with the connector off - no power. don't need to measure with volts connected.

Once you say you got 4.5 on the 1K scale so that is 4.5k ohms. And possible. but nothing between 1 & 3 nothing between the others, maybe measurement error. You should get a reading between any two - all pairs.

one pair never changes other two change.

And you say you got this I think with connector on and power on? how are you changing the wiper position?
DC volt 10 Good
1&3=4.8v Probably good this looks like the resistor
2&3=3.2v Should change as wiper moves
1&2=.7to.8v rapid fluctuation Good!! Tells me the wiper is #2 and it is at the bottom of travel maybe fluctuating with idle air movement?

Trouble is the 2,3 voltage should be fluctuating too, up at the 3.2V. I would expect the .7 to go higher toward the 3.2 as you raise the rpm.

I'm sorry, I don't know what moves the wiper. If you take it off I'm sure you will see a hole for a shaft or a shaft that goes into the air horn box. Find a way to rotate the wiper while measuring the resistance from 2 to 1.

I would expect it to go from 0 to 4.5k ohms and 2 to 3 to do the opposite.
It needs to be a smooth change, no skipping or jumps. Some one has posted pictures of the thing appart and it shows the wiper and the circular resistor made of carbon deposited on a ceramic substrate. His wiper had worn through the carbon resistor in under the wiper so he just bent the arm of the wiper to move the wiper over to good resistor and it worked. (for a while not a ling term fix)

Gary

Hi Gary, glad your back, The new pot. came in today I will not have time to do much for the next few days, have to keep a couple of date's I can't get out of.But as soon as I can I will take several readings from the new unit before I put it on,and after it is on, will keep you advised as to condition of the car, as for now it is much better in the fuel department,just a little rough idle and search on deceleration,and when you first start the car it stutters for a second be for going on to reasonable but not great idle.jnt

how are you guys measuring current at the eha in series?

__________________
1986 300SDL, 211K,Dealership serviced its whole life
1991 190E 2.6(120k)
1983 300D(300k)
1977 300D(211k)

Current measurements are taken in series.

__________________
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