1987 GMC Jimmy
Automobile Hoarder
- Joined
- Jan 23, 2016
- Posts
- 5,848
- Reaction score
- 2,389
- Location
- Mississippi
- First Name
- Jesse
- Truck Year
- 1987
- Truck Model
- V1500 Jimmy
- Engine Size
- 350
As far as I know there is not polarity on the injectors and you can not install them backwards because there is a little pin on them that has to sit in a slot on the injector pods. Otherwise you crack the injector pod and get to search for a new throttle body...ask me how I know this.
The injector do click when they are pulsed with a 12 volt source. I actually have three sets (like I said ask me how I know that the parts of the throttle body crack easily). One isn't in great condition but the other two sets I have tested and as far as I can tell function as they should. Originally I was told that you could test the injectors with a 9 volt battery and I found out that it takes a 12 volt source to get them to cycle.
I have ordered an AC Delco ignition control module and I am going to try it out. The one I put on it was a house brand and I know that they can be picky about brands sometimes. I noticed that the voltage at the injectors was only around 5 volts, so I am wandering if the off brand icm isn't the issue. If this doesn't do it I guess she is going to sit until I can afford to pay someone to figure it out.
That may be worth looking into. The injector pulse and ignition aspect are controlled separately. You could also pull the ICM and have it tested just for kicks. I don't know. You've covered a lot of stuff. The only thing that comes to mind is when stuff gets funky in any computer controlled vehicle, the ECM may be on the fritz.