[crazypete]

Here's my take on the early eec fords (granted this doesnt help you much).....

These cars are extremely solid and regardless of what people say about the quality of these early 90's american musclecars, they are extremely durable and I've seen these motors do over 200,000. The problem is that ford had really weak electronics components. It's usually the sensors and computer chips that go first. I basically had the reverse of the same problem: the computer would shut off the relay at random times, killing the fuel pump. Then, after hard wiring the relay, the computer started telling me my MAF voltage was too low. I checked voltage manually and, if anything, it was too high. I kept tinkering with it, trying to figure out why nothing was working the way it should. All of a sudden, all of the black ground wires in the computer/sensor wiring harness went hot. Manually grounding it would get some very strange behaviour from the eec.....blah blah blah.

Got tired of it all, ripped it all out and did a nice carb conversion. I have NEVER had a mysterious stall since. The car ALWAYS starts now. I am no longer at the whim of some computer, I can walk up front and turn a screw if I feel it's too lean or too rich. If someone were to do everything right... $150 intake/$350 carb and $150 for mechanical fuel pump = $650 = The cost of replacing a computer and a mass air sensor + a little and total confidence in the vehicle from that point on.

For the neutral switch... The computer does not need to know what gear the vehicle is in or not in. It is an Engine control module. Just hard wire it off if it is causing problems.