Questioni have a 1994 pontiac sunbird witha a 2.0 an it wont start.i have fuel at the rail and ia have spark.the problem is that the injecters have 12volts at both wires. one wire is blue,one wire is green and one is black with red stripe.black with red stripe is common on all 4 injecters and the blue does 2 and the green does 2.the only thing that i have done is change the ecm and ran 2new green and blue wires from the ecm too the injector harness under the plenum. any help would be appreciated.thank you.
AnswerHi Jason,
The ecm completes the ground circuit of the injectors. There is a tester called a "Noid" light, that you can connect at the injector connector to see if it is recieving pulses from the ECM.
If there are no pulses, there may be a sensor problem with the crankshaft position sensor, or the throttle position sensor is showing wide open throttle, which could trigger a clear flood mode, where the injectors are not pulsed.
But proper fuel pressure is also required, not just good fuel, so test it with a gauge. Throttle body systems require 13PSI, but yours will be much more than that. 26 to 46 PSI with key on, engine off.
28 to 32 with engine running, and 75 PSI with the return line clamped off.
Van
Van
