GMC Repair: loss of power, throttle position sensor, fuel pressure regulator

Question
I have been experiencing a intermittent loss of power.
no fault codes found. Not even when the car runs. never the light on.
My car is a Opel  aspirated engine with a GM engine.

i have a C20XE end 1993 ,  Motronic 2.8

i replaced with  new parts from Opel :

-cylinder head
-valves
-catalitic converter+ central part+ final part
-DIS+ cables+ sparkplugs
-Fuel pump+ fuel filter+ fuel pressure regulator
-knock sensor
-Air meter sensor
-Water temperature sensor
-Air temperature sensor
-throttle position sensor
-O2 sensor
-cam shaft sensor
-air filter

I cleaned all the wires, i checked the compression and it is perfect.
I didn't replace the injectors ,ECU and the cranck shaft sensor.

Sometimes the car goes very fast and you feel it pushing you back in the seat.
Sometimes else it goes smoothly slow with no pushing.
When this occur the tester read all the parameters within the specs.

Do you think is a ECU problem? or the cranck shaft sensor? or injectors? Or the ECU wiring?
please help me
Simone


Answer
It could be ANYTHING with ALL of the parts that you have replaced, Any number of wiring problems can be the cause.

I would test the cran sensor. It is possible that there is an ECM (ECU) problem, But WHAT caused the ECM (ECU) to fail ?.

If it is a shorted component connected to the ECM (ECU) and you install a NEW ECM (ECU) you will destroy the new one.

You need to find the CAUSE before you replace the ECM (ECU).


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