1997 500 sl runs rich on left bank
 

The car runs rough at idle and rich on the left bank; I also have codes for miss fire on 5 – 8 cylinders. I have check vacuum and vacuum leaks, compression, had the injectors checked and cleaned, o2 sensor replaced. Plugs and boots coils have been check and/or swapped with other side and I still can not get it to idle correctly. If I watch pulse with on the scan tool the left bank is 3.5 ms or so and the Right Bank is 2.5 ms. Every thing leads me to the computer but I am not sure. Is there a way I can test further or someone I can send the computer to and have it check out before I just spend the money on a dream or am I looking in the wrong direction. Could I be missing something? What else could control the pulse with like this? car has 27000 miles on it

Hi

Your 97 vehicle should have 4 oxygen sensors fitted to it, try monitoring all 4 sensors and post the results of your findings. Values starting from a "Cold Start" through the "Warm Up" cycle would be a good combination to form an overview. Also if you can access the Adaptation Values for Idle and Partial Load (AKA-Fuel Trim) post them as well. Would also like to see your HFM Voltage and the Air Mass to get a better sense of what may be happening.

Thanks:cool:

All readings are at idle with engine at operation temperature
 

All readings are at idle with engine at operation temperature.
RPM 717 +- 20
MASS 6.08 +/- .25
Bank 1 long term +9.4
Bank 2 long term -7.0
O2 Sensors
1-1 .08 - .75 Mostly .08
1-2 .45 - .46
2-1 .06 - .75 Switches better
2-2 .46 - .47
Short Term Fuel
1-1 –2.3 to 1.6
1-2 99.2
2-1 5.5 to 9.4
2-2 99.2

TPS 2%
Calc engine load 18.8%

Also the current code is Miss fire on cylinder 7 / 8 and multi cylinder miss fire

Re: All readings are at idle with engine at operation temperature
 

You may have an Air Mass Meter problem, what is the HFM voltage?

My scan tool does not read HMF voltage. Can I read it manually and if so were do you recommend I read this at. Also Man Absolute pressure is around 11 + - 3

Yellow and green wire has .03 - .04 volts at idle
Yellow and white wire has 1.3 + or - .2 volts
Red blue had battery voltage
Brown had ground

Just a follow up, found the O 2 sensor was sending the correct voltage but the computer was not seeing the correct voltage. Did some research and found http://www.beckmanntechnologies.com was the people to see on reman computer and I was very surprised to find them 10 minutes away from my shop. I spoke with Steve and he told me to bring the car over and they would take a look. BOB hooked the computer to the car and thought the computer might do the trick grabbed one off the shelf installed it and problem solved. If any one needs any MB electronics I recommend going straight to them there prices are great and there service is better and they have one heck of an inventory as I seen for my self walking in there warehouse. Thanks for the help MrCjames