Yet another issue has surfaced in regard to NOT using a vehicle speed sensor. I'm dealing with old-school Chevy TBI fuel-injection. It was always my understanding that the computer made the switch to a "closed loop" status, when the engine reached operating temperature, which comes in the form of a signal from the engine coolant temperature sensor. Now someone is saying that the VSS also needs to be present in the equation. Does anyone know if this is true??? You can technically operate an engine in open-loop at all times, but doing so is cutting corners way too much.

MonsterGM. That is what i was told by the smog referee. I do not know weather it is true or not, but either way I have to have one for emissions. I would highly reccomend one. Having one would improve your gas milage, driveability, and idle.

All you have to do is pull your guage cluster, snip the yello wire coming from the vss box behind speedo, hook it up to the vss in your FI harness. Good luck.

Charlo