PeachParts Mercedes-Benz Forum - View Single Post - Need help! 1988 190E won't rev up, seems to run very lean

JamesDean · #4 08-08-2013, 08:33 AM

A good next step would be to get a multi-meter and probe the x11 port (driver's fender) and see what the duty cycle is at. I believe you want pin 3 = + probe, pin 2 = - probe.

Ideally it should be fluctuating 40-50% after 1-2 minutes at idle. This is normal operation.

IF you see a fixed value, like its stuck at 29.9% or 30% (or some other percentage) and does not move at all when you give the car throttle... Then you have a faulty component. The CIS book will tell you what to check for. I think thats in the above pdf. If not let me know.

If you see it fluctuating at like 70-80% or 10-20% then you need to adjust the lambda tower and get it back to 40-50% duty cycle.

This car wouldn't happen to have ASR would it?

Hope this helps!