Duty cycle/EHA tests.....Round two

[Cap'n Carageous]

I reversed the leads on the duty cycle tester. Key on ignition off gave zero numbers for both meters. On ignition I got this;

[Cap'n Carageous]

Then this at 2000 rpm

[Cap'n Carageous]

Then this at return to idle. ?????

[Cap'n Carageous]

Then this...

[Cap'n Carageous]

Fianally this...

[Cap'n Carageous]

And a picture of part of the soot on the floor from the exhaust.

[Cap'n Carageous]

Adjusting the mixture screw had no effect on any meter readings, it just made the engine run worse.

[sbourg]

Sorry to complain, but it is still rather difficult to read from some of your pics - is that a vacuum gauge, tach?. In many cases, such as id on a part, or showing how something is assembled, etc, a pic really can be worth a thousand words. In this case, though, a few dozen would be lots better. All the meters are telling you is data, and tabulating it in text is far the easiest way to read it.

Now it is possible the equipment is hooked up wrong, and someone might spot that in a flawless pic, if true. That, though, might require the resources of a good photography studio. This automotive stuff often seems to be highly non-photogenic.

Anyway, IMHO. Don't want to offend, just to help you get your problem resolved. My meager input on your problem is that if mixture adjustment does not affect EHA current, you are open loop - no lambda control. Does your OVP work?

Steve

[josev]

when i had that same problem it turn out my fuel distributor went bad.the part i keep asking and never get an answer
why when the eha reads rich the dutycycle reads lean just like in your pictures.then when the eha reads lean the dutycycles read
rich
steve said worried about the eha reading but all the info refers
to x11 for all diagnostic if you modified you air intake to bring in more air then you need to richen the fuel a little to match the air coming in. more air than fuel choke the engine and vise versa
also why is it everyybody discribe the same exsact problem
but the fix is different .

[Cap'n Carageous]

The guage is fuel pressure at the cold start valve port. It was steady at 5.5 bar falling to 3.5 bar with the engine off. The basics of the meter readings were a constant 39.3% on lambda except when it jumps to 96% and then returns to 39.3.% The eha readings are very active though. I tried to focus more on them than the lambda. OVP 'appears' to be working, I have power to the ABS and idle controller. Although the vacuum guage is not in the pictures, it read a steady 7.5 inHg. In addition, grounding the controller side of the O2 sensor through my body made no change to the EHA current. It's almost as if this thing is in 'partial' open loop. I have read that a fixed lambda reading in multiples of 10 indicates a fault, although I don't know what that would be for 40%.

[mhingram]

capn,
I had the same problem with my readings except my eha was static as well. I am assuming you are using the eha cable that mb makes for diagnostics. The sears multimeter the positive(red) should be on the #2 port and negative (black) should be on the #3 port of the x11. Key on engine off should read 70%, if not then chack the cd manual it will tell you the error. If this is not fluctuating then you are in an open loop. The EHA as steve says is the key to adjust the system to your eha number and the duty cycle should match, although the O2 sensor should effect the eha reading.
good luck.
m

[josev]

Key on engine off should read 70%, if not then chack the cd manual it will tell you the error
it suppose to read 50% not 70%

[mhingram]

Josev,
You may be right I am talking about a 560sel and it should read 70% or 80% if it is a california car. So Capn check the manual for your car it should tell you the correct setting for your year and model.

[Cap'n Carageous]

Originally posted by Cap'n Carageous
I reversed the leads on the duty cycle tester. Key on ignition off gave zero numbers for both meters. On ignition I got this;

Oops, that statement is incorrect, Key on, engine off reading was 69.3% on duty cycle and +20.00 ma on EHA.

[mhingram]

looks good thats what you should get.
m