After a lot of part replacement and testing I am suspecting a bad knock sensor may be causing me to have a rich running problem (02 sensor reaches .94V). After disconnecting the knock sensor I noticed no change in the engine timing or fuel mixture - does this mean anything? Can I test the knock sensor?

Engine Idles at 12 deg. and increases until off the timing guage when throttle is applied. At the upper end of the timing (when throttle is applied) I notice that the timing mark shifts back and forth a few degrees - like it's searching for the right high RMP idle - is this normal?

Thanks to all the poeple on the board who have got me this far.


Below is my previous post for some background on what I have done:



I have an 1985 760 Turbo with 185000 miles. The initial symptoms were the car would run for 5-10 minutes and then choke - I would wait and then start again, go 2 miles and it dies again. After being towed home I spent the next 6 months trying to fix the problem - after many parts, time, and research I have learned a lot about the car but not yet fixed the problem.

Car will start and run fine but O2 sensor reads between 8.9 and 9.3 Volts meaning a rich mixture - will typically choke on gas about 15-20 minutes after running.

Here is what has been in order over a 6 month:

-Throttle Body cleaned
-Fuel pressure regulator has been replaced
-Fuel relay checked – operational
-Injector Ballasts tested for proper resistance - check
-Fuel pumps both working – audible
-All fuses intact
-Air filter clean
-Hall Sensor gauge jumps when cranking - assume operational
-Cap and Rotor replaced
-Coil to Distributor Wire Replaced
-Coil swapped with new coil - no fix
-ECT (Engine Temp Sensor) replaced twice and tested
-O2 sensor replaced - readings are true - leans when induce air leak
-Engine wire harness - removed - much corrosion, replaced all bad wiring and --installed
-Injectors cleaned and balanced.
-Engine computer swapped - no fix
-No leaks found in piping
-Throttle switch checks out - unpluggin increases idle and otherwise clicks right.
- Spark tested - jumped 1/4 inch with blue spark



Thank you