Fiat Single Point Injection - Nick Field
Here's a little story

Seicento 1.1, starts hunting when warmed up on idle, then after about 5 mins, injection firewalls the throttle all the way to the rev limiter. Repeatable. Nice in traffic.

AA home start takes one looks and wants to run away - car ends up at franchised Fix It Again Tony dealer.

Firstly I am told that the whole throttle body (potentiometer, stepper motor, injector, regulator) need replacing. But when I query the actual fault, the stepper motor is indicated. So I instruct them to just replace the stepper motor.

I get a call a day later, to find the the stepper motor has not cured the problem. On enquiring why, I find out that they have rounded the retaining bolts (apparently locktited in) and the the only solution is to go and replace the whole throttle body, which I am told is not available on its own, but comes with, guess what, the potentiometer, injector, regulator and stepper motor - total cost £460.00.

When I want confirmation that this will cure the fault, I get the answer "we think so". When I come down off the ceiling, and ask what happens if it does not cure the fault - they agree that it would be their problem.

Then I get back into my 1987 Mini and give thanks to the good old SU carb.