Quote:
Originally Posted by MBeige
I've had a similar issue with my former '89 190E 2.6.
O2 sensor was causing chaos with the duty cycle, IIRC. Basically it rendered the adjustment non functional because there was no longer a loop/feedback from the sensor.
However, the EHA was also causing high idle at operating temperature. Bought a new Bosch unit and fixed the problem. The car is gone but I still have the EHA.
Even with a non-leaking EHA, if it was not good it would wreak havoc on the idle and throttle response. |
thanks for the input! After some tests to the temp sensor/wiring, FPR, and ECU, I'm leaning toward replacing the actual EHA as you did above. I have a constant 90% duty cycle with absolutely no fluctuation, high idle after reaching operating temp and lacking in power toward the upper rpm range. I will try and track down a known working EHA to verify this is the root cause prior to taking the plunge and buying new.
Temp Sensor - .60k ua on the DMM & just under 5v at both connectors
Swapped in a different FPR with no changes (as expected)
Swapped in a different ECU with no change
I ran the car without an ECU plugged in & it ran exactly the same... just with the 100% duty cycle error. Car did not start once the original ECU was plugged back in... it was real low on gas upon the start of testing, so I'm thinking I ran it dry. Will refill & resume troubleshooting. FUN!