New 928 owner needs help in north Florida

I recently bought a 44k mile 11985 928s in New Smyrna Beach, Fla. The car appeared flawless. i put it in a local shop in the Daytona Beach area for some touch-up work to prepare the care for the drive to my home in Pennsylvania, near Philadelphia. All went well until two weeks ago, when the shop proprietor told me the MAS had gone crazy- spouting black smoke. I bought a rebuilt MAS from ERI in Arizona, and expected the best - that with the installation, the car would run as well as it had when I had test driven it. It doesn't. It belches black smoke and the shop proprietor has made no progress in aligning the mixture driving conditions. The car runs hopelessly rich, and the proprietor has no idea how to solve the problem. He says he has followed all the instructions from ERI, and used the correct gauges. His shop is small, and he is not an expert on 928s. I am now stuck with a non-running car, almost 1000 miles from home. i need to find an expert 928 technician within a couple of hundred miles of Orlando-New Smyrna Beach-Daytona. I'm sure there must be 928 experts in north Florida - with the proper diagnostic equipment to deal with this problem. I just don't know who any of them are.

Thanks in advance, David.

Please check the Roadside Assistance Forum for a post by Jim Bailey. He'd be a good person to ask.

Let me know if you need help finding the Forum or info.

Cheers,
Bill

The most likely cause for a mixture so rich it produces black soot from the exhaust is the temp II sensor. It is a thermistor. The LH 2.2 changes the pulse to the injectors based partially on its input from this sensor. When they fault, they tend to fault to infinite resistance which simulates -40° temps. This is supposed to produce a super rich mixture.

Locate the blue plug connector on the coolant water bridge and disconnect the temp II plug. Place a bridge wire between the two terminals of the plug. This simulates a fully warm engine. Start the car and observe any changes.

Note that if this works, it doesn't diagnose whether the fault is with the wiring or the sensor itself. Diagnostics for both are provided in the Factory Workshop Manuals. You need the LH 2.2 pin-out to compare the ECU input with the measurement from the sensor apart from the rest of the circuit.

For future reference, I would suggest starting a topic of this nature to the Technical Discussion Forum instead. It would solicit more responses that relate to your issue there. Also, specifying as much as you can with regard to your car is helpful to those of us who may be able to offer assistance. Euro or US spec? Transmission details?

David,

I'd recommend calling Lou Verdiales at Aero Dynamics (Phone #386-304-0380) in Port Orange, FL, which is adjacent to Daytona Beach. He'll definitely find and fix the problem with your 928 so you can be on your way home as soon as possible.

If you need another shop with good 928 skills and experience try Dan's Werkshop at 321-724-3059 in West Melbourne. It's a little further south, but they will fix your car as well.