Could this a be a bad wiring harness.

[mitsueclipse2g]

Heres the problem with my talon, I believe it may be the wiring harness causing all the problems. When the car starts it will run like crap and run really rough. Sometimes it will run fine, then you turn it off and on again it will run like crap again. It will run on two cylinders and when you shut it off it will fire on the other two cylinders. When it does run right it is getting good compression, and there are no boost leaks or vacuum leaks. Do you think there may be a short in the harness?

 

[Jimmyskrew face]

Heres the problem with my talon, I believe it may be the wiring harness causing all the problems. When the car starts it will run like crap and run really rough. Sometimes it will run fine, then you turn it off and on again it will run like crap again. It will run on two cylinders and when you shut it off it will fire on the other two cylinders. When it does run right it is getting good compression, and there are no boost leaks or vacuum leaks. Do you think there may be a short in the harness?

That could be anything.. It could be your mpi relay acting up, a ecu with bad caps.. ect.. things like that you have to trouble shoot. Even look into your grounds and make sure theyre all good.

 

[mitsueclipse2g]

All the grounds are good, they were all cleaned up. The ecu is good, we swapped out other ecus and it just ended up doing the same thing. The other thing is, it isn't throwing any check engine light codes.

 

[mitsueclipse2g]

Does any one know if these are symptoms of a bad wiring harness?

 

[rstchris]

It will be very hard to diagnose a wiring harness, look in to fuel pressure (pump/filter/injectors) stuff like that.

 

[mitsueclipse2g]

Thats the thing, everything was checked more than once and they are all good. Like I mentioned before you will start it and it will good, next thing you know you turn it off and on later and it starts running like crap again. It may be wires in the harness itself burned out and shorting out.

 

[Jimmyskrew face]

Thats the thing, everything was checked more than once and they are all good. Like I mentioned before you will start it and it will good, next thing you know you turn it off and on later and it starts running like crap again. It may be wires in the harness itself burned out and shorting out.

Was the original harness swapped out for some reason? Because its usually kind of rare to have harness issues unless it was swapped out or interfered with. If all your grounds are good. Then you have to play the game. Which means you have to go over all your electrical connections. But being that its intermittent, I'd think its something esle other than electrical.