Spedo out of Calibration

[MidEngineManiac]

I've been trying to track down this one since I bought the car, a 93 GT with power everything, 3300 motor and 3-speed auto.

On the drive home it quit, totally. The seller (private guy) felt bad enought that he had it fixed at his expence, and the end result was a new (used) ECM was installed.

Since then, everything works--EXCEPT--my speedo shows roughly 50-60% of the actual road speed. I've learned by following the flow of traffic that when it shows 40-45kph, I'm actually doing 80-90. When it shows 30, I'm doing around 50.

I'm thinking, since everything else is fine, this ECM origanaly came out of either a stick shift or a 4sp/overdrive car.

I'm wondering, if I pull the ECM and open it up, am I going to find a set of DIP switches that can be set for different motor/tranny combinations?



TIA

Mike

[Matt95GT]

I'm thinking, since everything else is fine, this ECM origanaly came out of either a stick shift or a 4sp/overdrive car.

I'm wondering, if I pull the ECM and open it up, am I going to find a set of DIP switches that can be set for different motor/tranny combinations?


Impossible - all 3300 GA's were mated to a 3-speed automatic. Only possible scenario - the PCM came from a 3300-powered Buick or Olds with a different trans/ratio and therefore different VSS signal. There won't be any way of changing that short of replacing the PCM or the memcal PROM in it though.

[doobiess]

all i can think is the speedometer cable is gummed up? maybe that needs replacing but thats all i can think of

[Matt95GT]

all i can think is the speedometer cable is gummed up? maybe that needs replacing but thats all i can think of

Not a mechanical cable. It is 100% electronic. The odometer is driven by a stepper motor.