GMC Repair: injector pulse, gmc sonoma, pink wire

Question
Hi, I have a 1995 gmc Sonoma ls 2.2 l standard trans. I have no injector pulse on #2,3. spark at all 4 cylinders. truck does run on #1,4 cylinders. tried a used ecm with the original prom; same symptoms.the Haynes wiring diagram shows a dark green wire going directly from the ecm to #2,3 injectors. how do I check this wire? how do I check if ecm is sending a signal? is this dark green wire the ground side? the wiring diagram shows a pink wire leading to all 4 injectors with 12 v.

Answer
Allen,

You can check the wire by poking a probe into it at the computer and checking for continuity between that and the injectors.  Did you try trading places with the working injectors and the non-working to eliminate the injectors themselves?  Did both of these cylinders begin misfiring at the same time, or did it run on 3 for a while then start running on 2?  If both quit working at the exact same time then it would almost certainly be a problem with that wire that goes to both of those injectors.  I would almost eliminate the ECM as the problem if you have already tried a different one.  Maybe try a third if possible just to be double-sure.

If you have a pink wire going to all 4 then it must be good if two of them are working.  You are right, it about has to be that green one if those two injectors are both good.  Check to see if it has worn through its insulation and is grounding out somewhere or if it has come disconnected someplace.

That's about the extent of what I can guess without being there to mess with stuff.  Best of luck to you!