Just got the 1986 911 3.2 registered 3 weeks ago and been driving the car daily all this time. You see my legs are really tall, So I wanted to retract the seat all the way back more than the stock position to sit comfortably. So told my fabricator to remove the seat and find a way to position the seat all the way backwards.
He did that all well, though he drilled right through the DME wiring harness.. Well, I did not know that. I started the car and suddenly a very very rough idle. And a tach that is not working. I was confused, just one hour ago the was very smooth. I thought the car was low on fuel, I refueled it. Still very rough, the car would just rev and rev then the rpm would go down to almost stall. One minute and then the car would give up and stall.
I thought my Idle control valve was seized, removed it and cleaned it, checked the three pins if it was closing and opening all was working. Then I moved to the Idle micro switch, I can hear the button clicking once the throttle is not moving and at "idle."
Then I ruled out the idle because when I drive the car and row throw the gears, the car basically hesitates at all speeds. Every three seconds there is a violent jerk like someone just hit the brakes. Rpms gos up easily when I apply the throttle but the hiccup is basically too violent to be fuel related issue. I noticed the half eaten wiring harness and I fixed all the wires individually and was confident that was my problem. The Tachometer was fixed but still the same rough idle/engine.
After that I was really confused, I fixed my messed up wiring harness and changed my DME relay to a spare relay I had. The problem was not fixed.. What could happen if the wiring harness shorted? What fuses/sensors could be burned?
I basically checked all these sensors and still I could figure out my hesitating engine:
- Checked both speed/reference sensors both has about 1153 ohms and looking good.
- Disconnected oxygen sensor and reconnected no difference.
- Removed the idle control valve and cleaned it.
- Tested the micro switch didn't see any difference.
- Changed DME relay
- Fuse box looks okay all new fuses
Now I removing the Actual DME computer and I am trying to open it and see inspect visually to see if there is cracked joints or anything.
So what could be my problem here? was my car running just find before the fabricator drilled through the harness. Fixed my wiring and still the same. Is it possible that the same time that this happened other stuff broke in the process? The only two possible culprits would be the AFM sensor or a sudden vacuum leak. How do I check AFM sensor?
I am literary stuck here.. Next week there is a track day and I wasn't expecting this sudden fallout.
Thanks for the help in advance, heres a coupe of pictures.
