injectors not firing

[rwcar1957]

HI I have 92 lumina z34. My injectors are not firing. I have fuel presure to the injectors.Looks like my fuses are fine.Changed the fuel pump relay. I tryed spraing gas in to the intake then it ran until i stop spraing gas. NEED HELP.

[Juglenaut]

The ICM controls them, it is possible the ICM burn out all power to them.

Do you have a test light?

[craftsman_454]

testing injectors

most gm use a ground side switch controlled by the pcm for injectors. so with the key on you should have 12v to each injector on one of the wires. THe pcm grounds the circuit by getting a signal from a camshaft position sensor or crank position sensor depending on make and model etc.

use a test lkight to check for the ground signal by hooking the test light up to the positive post of the battery. if the ground signal isn't there then check the wiring for a problem. any more q's let me know.

[SappySE107]

Check for spark as well. Sounds like the crank position sensor is bad.

[Juglenaut]

OBD1 the ICM controls the injectors and the kps or cps is directly integrated in the icm. OBD2 is different.

I would check to see if they all have power first, because grounding the switched negative side the injector solenoid opens.

You would almost have to look at the PCB of a OBD 1 to know the difference between that and a OBD2.