My 89 200TQ has begun to buck when the car is warmed up and under load, such as taking off from a stop heading up hill. Cruising there is no problem. This only happens when the car has warmed up. I've replaced the following items: fuel injectors and inserts; distributor cap, rotor, wires; all vacuum hoses; fuel filter, fuel pump, FP relay is OK; temp senders for ECU and Idle circuit,
I would like install the check engine light to read any codes but am not sure where to access terminal 31, and 33 on the ECU for it to blink out codes. Scott Mockry's site is not specific as to where that lamp can be hooked up to existing wiring.

Any suggestions or ideas?

knock sensor?

nt

nt

Disconnect knock sensor connector from harness and connect oscilloscope's high impedance input across knock sensor's output. With a small hammer, tap on engine block near knock sensor. You should see a squiggly trace in response to knocks.