Expert: Sean Halliday - 7/18/2007

Question
QUESTION: Car cranks, will not start. Good fuel pump, does get spark, excellent compression. When I attached a noid lite to the injector harness I get a steady light instead of a pulse when the car is cranking. I am thinking along the lines of a bad PCM. (previous owner said that the PCM might be bad caused by a bad ground wire.) Any thoughts?
Thanks for your wisdom.

ANSWER: The system in your car is the digital injection so the power will be constant to the injectors.As the engine turns ,the ECM will time the right amount of fuel to each injector/cylinder by way of the ground wire to each one.So,check your air flow meter,your distributor and also the ECM ground wire/wires.It is possible your ECM is bad ,rare but possible.The air flow meter has effect on the fuel injection as also the HALL effect distributor.Make sure both are ok.

---------- FOLLOW-UP ----------

QUESTION: Sorry, I forgot to mention that I did spray starting fluid into the intake. The car did not start, even temporarily. The Jetta does not have a crank/cam sensor, it has the old fashioned rotor, distributor cap. The rotor turns, the distributor cap is not pitted, the timing belt turns like it is supposed to. The car just will not turn over. The previous owner did say that the ground wire was bad and that this caused the PCM to fry. Ever heard of that one?
Thanks again.

Answer
Even though the timing belt is turning,check the timing is correct anyway.I have never heard of the PCM getting fried unless someone has fried it.Thats by too much voltage as they are very sensitive.The easiest way is to try a PCM and see if it starts,did this car run when you got it?