Have a late1999 I'm working on. I've done cyl contribution test and buss test with my modis scanner. Buss test comes back with cyl 3 high to low side short p1263. Removed both valve covers. Replaced with new gaskets and harness. Still nothing. Cyl 3 is not doing anything I can unhook the connector at the injector and no change in the way it runs. Ohmed out injector solenoid 2.4. Hooked up number 3 plug to new injector. Did buss test, same code. Checked harness from injector to idm, good conection and not shorted together or to ground or positive. Replaced idm, still sames code with buss test. I'm pulling my hair out as we speak.

 

That code indicates that the low side wire is shorted either to battery positive, or to the injector high side (common) circuit from the IDM. Check resistance between the low side socket in the wiring harness connector at the injector to the positive post on the battery. Resistance should be at least 10,000 ohms. If it's less, there's a short in the harness somewhere between the VC gasket and the IDM. The resistance between the low and high side sockets in the injector wiring harness connector. That reading should also be above 10k ohms.

 

With idm unhooked no connection to high side or battery positive or negitive

 

What about with the IDM connected? It's possible the IDM could have an internal short, I suppose.

 

Ok I figured it out finally my solus (I said modis in the first post) saves the codes from one buss test to the other. The more stuff I tried the codes came up. I cleared the codes and moved the solenoid to another injector and the problem followed that solenoid as long as I cleared the codes every time. Just need another solenoid. Hope this helps someone else.

 

Ah, that explains it. Glad it's figured out.