so I have been having a random problem with the motor cutting out the driver side and bogs bad and goes lean. If I wiggle the main coil harness plug it will go back to normal so leaning towards ordering a new connector. But why would it go lean if the coil was loosing power or ground? i would think it should go rich since it looses spark. The ecu grounds the injectors to fire so the coils dont share the grounds but they do share the same 15 amp ign fuses. So what do yall think main plug?

 

well rewired the coils and all was good this morning and what would you know this afternoon it was running lean again. Looks like cyl 3 injector was not firing but I grounded the injector and it started to go back rich. Wires from injectors to pcm have continuity and all the injectors have the same ohm. what could cause a random miss that kills fuel on one cylinder? just about to the point of thinking the pcm is messed up.

 

It's really some something that you have to dig into with a high end scan tool and electrical test equipment.

You could put a noid light on the injector when its running like this and see what happens. My guess is that it's not seeing the signal and it won't flash indicating its not seeing the signal.

If it is seeing the signal, Its also possible that the injector or some of the injectors are stuck close when they heat up...

It is possible that the ECU is bad. I have seen that before but its usually pretty rare.

 

I put a led on the injector plug and it did flash but still no spark and still runs lean when it happens. Its really starting to confuse me as to why it would loose spark and go lean seems it would go rich. The only wire not in common with the other coils would be signal wire and since all the rest fire seems it would be between the coil wiring or pcm. But still leaves a question of why it goes lean

 

How are you determining its goin lean? If your going off a wideband a miss will read lean because the fuel is unburned and the sensor only reads the oxygen pumped out of the cyl.

 

Yeah it was off the wideband but I think I have it figured out. Somehow the injector and reference wire had continuity on cylinder 3 got that fixed and so far 2 daysdays with no trouble

 

So was it a wiring issue or an issue with the injector??? Or was there an issue with the ECU.

 

Wiring i guess i took off the coils and checked continuity an all was good so i guess I had smashed a wire installing them maybe. but its running better now. but still not 100% what was causing it.