Required: Multimeter with duty cycle. 1. Remove air cleaner and unscrew the cover of the diagnostic socket on the fender (on the fuel/ignition box there). 2. Set the meter for duty cycle and put the red probe in the #3 hole and the black probe in the #2 hole in the diagnostic socket. 3. Switch ignition on but do not start engine. Should read 70%. 4. Start engine. Duty cycle will be 50% until the oxygen sensor warms up, at which point it will go way down to 30% or less if you are running rich and the electronics are working. Let the car idle and heat up to 80C. 5. When the computer is controlling the mixture, it will read something other than 50% and will change all the time. At this point, you can use a 3mm Allen wrench to adjust the mechanical fuel mixture at the fuel distributor. Insert Allen, then press down GENTLY to engage the key in the screw. Don't press very hard, you will shove the mass flow sensor flap down and add extra fuel. 6. Clockwise is richer, Counter clockwise is lean, only turn in SMALL amounts. 7. Turn the Allen slowly and release the pressure, then wait a bit to see where the reading goes. At idle it will take 10 sec or so for the change to show up, and if you get carried away, you will have trouble getting the correct reading. 8. Adjust in small increments, 1/16 turn or so at a time, until you get a reading close to 50% duty cycle. This should set the EHA current at close to 0, giving you proper fuel mixture control. 9. Now, the fun starts. If you cannot obtain anything but 50% duty cycle with no changes, the O2 sensor is bad or unhooked (connector is under the floor mat in front of the passenger side front seat). If it changes, but you cannot set it to 50%, something else is wrong. 10. You should get momentary enrichment (lower duty cycle %) when you open the throttle, going back to 50% quickly. If you get the opposite, you probably have a bad mass air flow potentiometer, so the computer doesn't get signaled you opened the throttle. 11. Your car should now be around 45-55%. Now rev the motor up to around 2500rpm and it should be 10 less then your idle number %. If not, you need to re-adjust the EHA. 12. The EHA is a small black box located on the side of the fuel distributor. There is a screw in the middle that needs removed and a 2mm Allen key is required. Counter Clockwise is leaner, clockwise is richer. 13. If your car is running say 25% at 2500rpm turn it counter clockwise (to lean it out), if it's like 70% turn it clockwise (to richen it up). It doesn't take much, turn it ONLY A 1/8 AT A TIME. I have mine set to 45%-50% at idle, 38%-40% running at 2500rpm. 14. Get it right and you won't believe how much happier your car is. You have to play with it though cause my numbers won't match yours. Note: The lower the % means the car is to rich. The higher the % means the car is to lean. You don't have to do the EHA adjustment
Required: Multimeter with duty cycle. 1. Remove air cleaner and unscrew the cover of the diagnostic socket on the fender (on the fuel/ignition box there). 2. Set the meter for duty cycle and put the red probe in the #3 hole and the black probe in the #2 hole in the diagnostic socket. 3. Switch ignition on but do not start engine. Should read 70%. 4. Start engine. Duty cycle will be 50% until the oxygen sensor warms up, at which point it will go way down to 30% or less if you are running rich and the electronics are working. Let the car idle and heat up to 80C. 5. When the computer is controlling the mixture, it will read something other than 50% and will change all the time. At this point, you can use a 3mm Allen wrench to adjust the mechanical fuel mixture at the fuel distributor. Insert Allen, then press down GENTLY to engage the key in the screw. Don't press very hard, you will shove the mass flow sensor flap down and add extra fuel. 6. Clockwise is richer, Counter clockwise is lean, only turn in SMALL amounts. 7. Turn the Allen slowly and release the pressure, then wait a bit to see where the reading goes. At idle it will take 10 sec or so for the change to show up, and if you get carried away, you will have trouble getting the correct reading. 8. Adjust in small increments, 1/16 turn or so at a time, until you get a reading close to 50% duty cycle. This should set the EHA current at close to 0, giving you proper fuel mixture control. 9. Now, the fun starts. If you cannot obtain anything but 50% duty cycle with no changes, the O2 sensor is bad or unhooked (connector is under the floor mat in front of the passenger side front seat). If it changes, but you cannot set it to 50%, something else is wrong. 10. You should get momentary enrichment (lower duty cycle %) when you open the throttle, going back to 50% quickly. If you get the opposite, you probably have a bad mass air flow potentiometer, so the computer doesn't get signaled you opened the throttle. 11. Your car should now be around 45-55%. Now rev the motor up to around 2500rpm and it should be 10 less then your idle number %. If not, you need to re-adjust the EHA. 12. The EHA is a small black box located on the side of the fuel distributor. There is a screw in the middle that needs removed and a 2mm Allen key is required. Counter Clockwise is leaner, clockwise is richer. 13. If your car is running say 25% at 2500rpm turn it counter clockwise (to lean it out), if it's like 70% turn it clockwise (to richen it up). It doesn't take much, turn it ONLY A 1/8 Required: Multimeter with duty cycle. 1. Remove air cleaner and unscrew the cover of the diagnostic socket on the fender (on the fuel/ignition box there). 2. Set the meter for duty cycle and put the red probe in the #3 hole and the black probe in the #2 hole in the diagnostic socket. 3. Switch ignition on but do not start engine. Should read 70%. 4. Start engine. Duty cycle will be 50% until the oxygen sensor warms up, at which point it will go way down to 30% or less if you are running rich and the electronics are working. Let the car idle and heat up to 80C. 5. When the computer is controlling the mixture, it will read something other than 50% and will change all the time. At this point, you can use a 3mm Allen wrench to adjust the mechanical fuel mixture at the fuel distributor. Insert Allen, then press down GENTLY to engage the key in the screw. Don't press very hard, you will shove the mass flow sensor flap down and add extra fuel. 6. Clockwise is richer, Counter clockwise is lean, only turn in SMALL amounts. 7. Turn the Allen slowly and release the pressure, then wait a bit to see where the reading goes. At idle it will take 10 sec or so for the change to show up, and if you get carried away, you will have trouble getting the correct reading. 8. Adjust in small increments, 1/16 turn or so at a time, until you get a reading close to 50% duty cycle. This should set the EHA current at close to 0, giving you proper fuel mixture control. 9. Now, the fun starts. If you cannot obtain anything but 50% duty cycle with no changes, the O2 sensor is bad or unhooked (connector is under the floor mat in front of the passenger side front seat). If it changes, but you cannot set it to 50%, something else is wrong. 10. You should get momentary enrichment (lower duty cycle %) when you open the throttle, going back to 50% quickly. If you get the opposite, you probably have a bad mass air flow potentiometer, so the computer doesn't get signaled you opened the throttle. 11. Your car should now be around 45-55%. Now rev the motor up to around 2500rpm and it should be 10 less then your idle number %. If not, you need to re-adjust the EHA. 12. The EHA is a small black box located on the side of the fuel distributor. There is a screw in the middle that needs removed and a 2mm Allen key is required. Counter Clockwise is leaner, clockwise is richer. 13. If your car is running say 25% at 2500rpm turn it counter clockwise (to lean it out), if it's like 70% turn it clockwise (to richen it up). It doesn't take much, turn it ONLY A 1/8
It would be a helpful vid if you just show the entire instructions or post a link for them, and explain which pins did you connect the probes and how to do the measurements, instead of jumping around here and there.
so assuming the idle speed is correct, air flow plate adjusted to read 50% at idle, and at 2500rpm 40%, the eha needs a tweak if the "high revs" duty is to low or to high... eha seems to be the hi speed running adjustment, where as air flow plate is a static idle adjustment. or eha is the fine adjustment. wow, really is 02 sensor hungry system.. i wonder what happens if you have a non functional o2 sensor...
EHA is the connection between the ECU and the mechanics. It is supposed to fine tune the fuel mixture. It enriches or leans the mixture. If bad, the motor will have poor acceleration, bad engine braking and higher consumption.
Hi! I have a non kat, non O2 car. When at idle it read 50% and when I go go 2,5k rpm it stays 50%. That means I need to adjust the EHA? Or maybe faulty ECU? (Already replaced potentiometer with OE part)
@@190mex The car does not have a cat or a O2 sensor. The problem is with idle surging up and down. I checked the mixture and it stays around 50% at idle and also if i rev it up, still 50%. Idle surging starts only when it gets up to operating temp. If I unplug the IAC it idles good, just at higher rpm. Is there a posibility of an ECU or fuel relay failure/faulty? I've replaced so far: -IAC (tried 2 used ones and a new one, all run same) -all rubber hoses to and from IAC -rubber between fuel distributor unit and throttlebody -fuel filter -OVP -microswitch -OE potentiometer -spark plugs and wires -dizzy cap and rotor
Check again with cigarete smoke put silicon glove on kejetronic airflow meter hole an put smoke with hose on air intake right from air flow disc youbhave vacuum leak some where.
con quelle inquadrature perse nel vuoto e fissate sulle parti di carta, l'operazione si capisce solo se gia' la conosci......cosi',non si capisce un caxxo......
190mex of course,could I contact You through Facebook or somehow,i see that you really know about that KE. I have some shit problems with my 190 but we dont have any mechanic that understands KE.
Required: Multimeter with duty cycle.
1. Remove air cleaner and unscrew the cover of the diagnostic socket on the fender (on the fuel/ignition box there).
2. Set the meter for duty cycle and put the red probe in the #3 hole and the black probe in the #2 hole in the diagnostic socket.
3. Switch ignition on but do not start engine. Should read 70%.
4. Start engine. Duty cycle will be 50% until the oxygen sensor warms up, at which point it will go way down to 30% or less if you are running rich and the electronics are working. Let the car idle and heat up to 80C.
5. When the computer is controlling the mixture, it will read something other than 50% and will change all the time. At this point, you can use a 3mm Allen wrench to adjust the mechanical fuel mixture at the fuel distributor. Insert Allen, then press down GENTLY to engage the key in the screw. Don't press very hard, you will shove the mass flow sensor flap down and add extra fuel.
6. Clockwise is richer, Counter clockwise is lean, only turn in SMALL amounts.
7. Turn the Allen slowly and release the pressure, then wait a bit to see where the reading goes. At idle it will take 10 sec or so for the change to show up, and if you get carried away, you will have trouble getting the correct reading.
8. Adjust in small increments, 1/16 turn or so at a time, until you get a reading close to 50% duty cycle. This should set the EHA current at close to 0, giving you proper fuel mixture control.
9. Now, the fun starts. If you cannot obtain anything but 50% duty cycle with no changes, the O2 sensor is bad or unhooked (connector is under the floor mat in front of the passenger side front seat). If it changes, but you cannot set it to 50%, something else is wrong.
10. You should get momentary enrichment (lower duty cycle %) when you open the throttle, going back to 50% quickly. If you get the opposite, you probably have a bad mass air flow potentiometer, so the computer doesn't get signaled you opened the throttle.
11. Your car should now be around 45-55%. Now rev the motor up to around 2500rpm and it should be 10 less then your idle number %. If not, you need to re-adjust the EHA.
12. The EHA is a small black box located on the side of the fuel distributor. There is a screw in the middle that needs removed and a 2mm Allen key is required. Counter Clockwise is leaner, clockwise is richer.
13. If your car is running say 25% at 2500rpm turn it counter clockwise (to lean it out), if it's like 70% turn it clockwise (to richen it up). It doesn't take much, turn it ONLY A 1/8 AT A TIME. I have mine set to 45%-50% at idle, 38%-40% running at 2500rpm.
14. Get it right and you won't believe how much happier your car is. You have to play with it though cause my numbers won't match yours.
Note:
The lower the % means the car is to rich.
The higher the % means the car is to lean.
You don't have to do the EHA adjustment
No one else is saying it, so i will.
Thank you!
Thank YOU very much !!
Thanks bro
thank you
First of all thanks for your info ....
Mine is 50.7% idle 50.9 % revving around 2.5k
iam just wondering what the purpose of your video since ur not talking not reading not showing any thing you doing
could you please add that document that you were reading in the video to the discerptions
Required: Multimeter with duty cycle.
1. Remove air cleaner and unscrew the cover of the diagnostic socket on the fender (on the fuel/ignition box there).
2. Set the meter for duty cycle and put the red probe in the #3 hole and the black probe in the #2 hole in the diagnostic socket.
3. Switch ignition on but do not start engine. Should read 70%.
4. Start engine. Duty cycle will be 50% until the oxygen sensor warms up, at which point it will go way down to 30% or less if you are running rich and the electronics are working. Let the car idle and heat up to 80C.
5. When the computer is controlling the mixture, it will read something other than 50% and will change all the time. At this point, you can use a 3mm Allen wrench to adjust the mechanical fuel mixture at the fuel distributor. Insert Allen, then press down GENTLY to engage the key in the screw. Don't press very hard, you will shove the mass flow sensor flap down and add extra fuel.
6. Clockwise is richer, Counter clockwise is lean, only turn in SMALL amounts.
7. Turn the Allen slowly and release the pressure, then wait a bit to see where the reading goes. At idle it will take 10 sec or so for the change to show up, and if you get carried
away, you will have trouble getting the correct reading.
8. Adjust in small increments, 1/16 turn or so at a time, until you get a reading close to 50% duty cycle. This should set the EHA current at close to 0, giving you proper fuel mixture control.
9. Now, the fun starts. If you cannot obtain anything but 50% duty cycle with no changes, the O2 sensor is bad or unhooked (connector is under the floor mat in front of the passenger side front seat). If it changes, but you cannot set it to 50%, something else is wrong.
10. You should get momentary enrichment (lower duty cycle %) when you open the throttle, going back to 50% quickly. If you get the opposite, you probably have a bad mass air flow potentiometer, so the computer doesn't get signaled you opened the throttle.
11. Your car should now be around 45-55%. Now rev the motor up to around 2500rpm and it should be 10 less then your idle number %. If not, you need to re-adjust the EHA. 12. The EHA is a small black box located on the side of the fuel distributor. There is a
screw in the middle that needs removed and a 2mm Allen key is required. Counter
Clockwise is leaner, clockwise is richer.
13. If your car is running say 25% at 2500rpm turn it counter clockwise (to lean it out), if it's like 70% turn it clockwise (to richen it up). It doesn't take much, turn it ONLY A 1/8
Required: Multimeter with duty cycle.
1. Remove air cleaner and unscrew the cover of the diagnostic socket on the fender (on the fuel/ignition box there).
2. Set the meter for duty cycle and put the red probe in the #3 hole and the black probe in the #2 hole in the diagnostic socket.
3. Switch ignition on but do not start engine. Should read 70%.
4. Start engine. Duty cycle will be 50% until the oxygen sensor warms up, at which point it will go way down to 30% or less if you are running rich and the electronics are working. Let the car idle and heat up to 80C.
5. When the computer is controlling the mixture, it will read something other than 50% and will change all the time. At this point, you can use a 3mm Allen wrench to adjust the mechanical fuel mixture at the fuel distributor. Insert Allen, then press down GENTLY to engage the key in the screw. Don't press very hard, you will shove the mass flow sensor flap down and add extra fuel.
6. Clockwise is richer, Counter clockwise is lean, only turn in SMALL amounts.
7. Turn the Allen slowly and release the pressure, then wait a bit to see where the reading goes. At idle it will take 10 sec or so for the change to show up, and if you get carried
away, you will have trouble getting the correct reading.
8. Adjust in small increments, 1/16 turn or so at a time, until you get a reading close to 50% duty cycle. This should set the EHA current at close to 0, giving you proper fuel mixture control.
9. Now, the fun starts. If you cannot obtain anything but 50% duty cycle with no changes, the O2 sensor is bad or unhooked (connector is under the floor mat in front of the passenger side front seat). If it changes, but you cannot set it to 50%, something else is wrong.
10. You should get momentary enrichment (lower duty cycle %) when you open the throttle, going back to 50% quickly. If you get the opposite, you probably have a bad mass air flow potentiometer, so the computer doesn't get signaled you opened the throttle.
11. Your car should now be around 45-55%. Now rev the motor up to around 2500rpm and it should be 10 less then your idle number %. If not, you need to re-adjust the EHA. 12. The EHA is a small black box located on the side of the fuel distributor. There is a
screw in the middle that needs removed and a 2mm Allen key is required. Counter
Clockwise is leaner, clockwise is richer.
13. If your car is running say 25% at 2500rpm turn it counter clockwise (to lean it out), if it's like 70% turn it clockwise (to richen it up). It doesn't take much, turn it ONLY A 1/8
It would be a helpful vid if you just show the entire instructions or post a link for them, and explain which pins did you connect the probes and how to do the measurements, instead of jumping around here and there.
www.benzworld.org/forums/w124-e-ce-d-td-class/1644686-duty-cycle.html
so assuming the idle speed is correct, air flow plate adjusted to read 50% at idle, and at 2500rpm 40%, the eha needs a tweak if the "high revs" duty is to low or to high... eha seems to be the hi speed running adjustment, where as air flow plate is a static idle adjustment. or eha is the fine adjustment. wow, really is 02 sensor hungry system.. i wonder what happens if you have a non functional o2 sensor...
EHA is the connection between the ECU and the mechanics. It is supposed to fine tune the fuel mixture. It enriches or leans the mixture. If bad, the motor will have poor acceleration, bad engine braking and higher consumption.
Saves como or how I can take off the little ball inside so I can adjust the fuel screw?
AlonSOAMAZING
Hi!
I have a non kat, non O2 car. When at idle it read 50% and when I go go 2,5k rpm it stays 50%.
That means I need to adjust the EHA? Or maybe faulty ECU? (Already replaced potentiometer with OE part)
What is year of production?
W201 1.8 1991
@@sittos191That means O2 sensor is not connect end ECU canot fine adjust the mixture becouse EHA is adjust by the ECU what is isues with engine?
@@190mex The car does not have a cat or a O2 sensor. The problem is with idle surging up and down. I checked the mixture and it stays around 50% at idle and also if i rev it up, still 50%.
Idle surging starts only when it gets up to operating temp.
If I unplug the IAC it idles good, just at higher rpm.
Is there a posibility of an ECU or fuel relay failure/faulty?
I've replaced so far:
-IAC (tried 2 used ones and a new one, all run same)
-all rubber hoses to and from IAC
-rubber between fuel distributor unit and throttlebody
-fuel filter
-OVP
-microswitch
-OE potentiometer
-spark plugs and wires
-dizzy cap and rotor
Check again with cigarete smoke put silicon glove on kejetronic airflow meter hole an put smoke with hose on air intake right from air flow disc youbhave vacuum leak some where.
When I push down the 3mm Allen wrench into the screw down the nozzle my engine dies. Is that normal? Might I have asserted too much pressure?
Too much pressure is very sensitive
Hi very thank you
Iam Omar from irap can you help me in car benz.I need to this failes tak bactur oll sarves
and thaks
Dude the economy meter goes to maximum red side, that means something wrong.
Hello! where find you this document?
On forum: www.benzworld.org/forums/w124-e-ce-d-td-class/1644686-duty-cycle.html
190mex thanks :)
is it the same for 2.3 E,it is the same engine,only bigger pistons
Yes
190mex is there a way for getting that sheet you are holding
Text from this forum: mercedes-190.co.uk/topic/6620540/1/
con quelle inquadrature perse nel vuoto e fissate sulle parti di carta, l'operazione si capisce solo se gia' la conosci......cosi',non si capisce un caxxo......
HI MAN YOU CAN SEND ME THATS MANUAL?
i had to disconnect the decel switch at the accelerator mechanism for me to be able to adjust duty anyone else
Wdym because I can’t adjust mine
can you show me the document to my email
why is everyone afraid to TALK on a video anymore? SMH
maybe he speaks german or is mute
lol
Send me this documents?
From net google :D
190mex
mercedes-190.co.uk/topic/6620540/1/
in this post,it says that when you turn ignition on,the reading schould be 70%,but mine is reading 90%.
Any tips?
www.markthomastrimming.com/storage/merc/boschfaultcodetable.jpg
190mex oo man,it is not assigned,what the heck does that mean :( mine is 1990.
are you put in corect pins 2is negative 3is positive ?
190mex of course,could I contact You through Facebook or somehow,i see that you really know about that KE. I have some shit problems with my 190 but we dont have any mechanic that understands KE.
190mex what readings are you using in the multimeter is it ohms or voltage? thanks