Help Please.....1986 928 Running Rich!
 

Hello all,

My 1986 928 all of a sudden started running excessively rich. Fouling plugs, black smoke, flooding. Pulling the spark plugs........all 8 are wet. Was thinking that the problem might be the coolant temp sensor. I changed the sensor and there was no difference.

I remember reading about someone with this exact problem years ago, but I can't seem to find the posting. I'm not sure if it was even on this forum.

Has anyone had a similar problem like this? Anybody that can offer some advice or experience would be greatly appreciated!

Thanks in advance! :)

I have an earlier model but search posts for "running rich"...odds are it is a sensor...O2 or other crank/cam type position sensor. Others will chime in with precise info that is confirmed in some of the previous threads.
Jon

Check if the Temp II sensor wiring is good.

>1K ohms cold, 300ish hot, between pins 2 and 25 at the LH connector. Check with the engine cold and hot.


Pinouts:

(EZF_LH22_32V.pdf)

(EZF_LH22_16V.pdf)

Check your MAF. If it fails the computer goes into limp home mode which has 2 settings. One for under 2000 rpm and one for 2000 rpm+. It will run rich in this mode.

Thanks everyone for the input!

JhW.....I keep thinking that it could be some sort of sensor as well! Coolant temp sensor was the first thought. It has a recent new 02 sensor. Not sure about the crank sensor or if it may cause this, but will do a bit more research.

porken......Thanks for the suggestion and thanks very much for the diagrams. I'm going to check out the wiring. Would make sense if there's a short somewhere.

jstobo.......Thanks. The MAF was also one of the things I was suspecting too! Thanks again for the info. Makes sense that this could be the problem too!

What would i do without all the helpful people on this forum?! :)

Become a severe alcoholic (like me).