I hope someone might be able to lend some insight to my issue. Iíve also included some diagnostic info the might help in deriving to a solution.
Over the weekend I replaced the main wiring harness on my 1994 C220Ö The reason in doing so was two fold... #1
There was a short in the cable going to the MAF sensor, thus I originally replaced that, but in doing so I noticed that when I peeled back the fabric tape going into the main coupler that connects to the ECU, that those wires where becoming exposed due to the coating on the wires cracking and falling apart when touched. Despite my best efforts to apply heat shrink to the now newly exposed wires before putting everything back together, a few of these exposed wires must have still touched internally in the reassembly process. After reconnecting the coupler to the ECU, reconnecting the battery and starting the car, there was electrical arching coming from under the newly taped area going into the coupler. Thus reason #2
, a this point a new wiring harness was the obvious course of action.
Once I installed the new Mercedes Benz manufactured harness, (not a third party harness) and all of the fitments matched up perfectly. I cranked my car here are the symptoms that I am experiencing:
- The car starts hard.
- It idles very roughly almost like it's running on 3 cylinders and wonít hold an idle unless you manually keep your foot on the accelerator, once you let off it stalls.
- This car has never produced any real visible exhaust smoke, but it does now when I rev it to prevent it from stalling.
I replaced the MAF sensor a few years ago with an OEM Bosch, (I accidentally dropped it while cleaning it and it was damaged) so up until the detection of the short in the MAF cable, the MAF sensor worked perfectly.
I have double and triple checked all of my connections both electrical and vacuum, and everything looks in order. I do own a scanner, and it is not throwing any codes, plus the check engine light is not on yet, this might be because the battery was disconnected for an extend period of time and the ODB memory has not had a chance to fully propagate.
My gut tells me this is an MAF Sensor issue
, that it possibly shorted out due to the electrical arching when I attempted to fix the old wiring harness, is this possible? Can you fry/short out an MAF sensor? Is there a way to bench test a MAF sensor?