pig rich, looking for ideas Options

[Facime]

So I just bought someone elses problems. Its a 95 GT with 183K on the clock. Previous owner had an issue with the car running poorly. Will start but barely run. He threw some parts at it, plugs, wires, complete dizzy with new cap/rotor, map sensor, TPS.

Once I got it I verified compression is good. mechanical timing is right. plugs were new but sooty black across the board. I pulled the ECU and the caps all look good inside.


So I'm leaning now towards massive overfueling. Besides the ECU is there any other way that injectors can stay open? some kind of short maybe (is there a resistor pack)

Any tips for testing fuel pressure at the rail? I'm leaning towards bad pressure regulator or plugged return line. Any other thoughts or ideas?


Thanks

[Box]

Coolant temp sensor, for the ECU, can also cause it to run overly rich to the point of being undrivable. I'd check it before the FPR as it's easier and less messy.

There's another coolant temp sensor that goes to the gauge in the cluster. So the one for the ECU can be bad without anything weird showing in the gauge.