Hi, Here is the details. 1974 914. Replaced the tired 1.7L engine with a 2.0L. Reused the new distributor and 40 Webbers. New engine has hydralic lifters. The car has an override switch as sometimes it will not start via the key switch. I suspect the sensor under the passanger seat causes this problem. Sometimes the car runs really rough and noisey like the lifters are not coming up but then it runs great. The relay on the engine circuit board which controled the fuel injection system was removed. I put one in and thats when the ignition switch and sensor under seat started to smoke indicating a short somewhere. My questions, 1) How do I get rid of the sensor under the passenger seat? 2) Could the electrical issues be causing erratic engine behaivor? 3) Can I isolate the engine systems from the rest of the electrical system? Thanks Dave

The logiv circuit under the seat is simple. unplug the two large yellow wires.
Connect them VERY solid...use solder.
That is the starter line.

With carbs you need only a few things.
You need the starter, that is the yellow wire under the seat.
You need 12V at the coil
You need the fuel pump circuit.

So, to test, and only for test.
Toggle switch to the coil
Toggle switch to the fuel pump.
Start car with key.

The fuel pump must be 3-5psi for carbs, not the stock pump (unless you have a pressure regulator in the fuel line system)

Rich