3.8 misfire

ktm909

New Member
Joined
Feb 8, 2023
Messages
5
Location
Goodrich mi
Can’t figure this out. Replaced plugs wires and coil pack only misfires on 1,3 and sometimes 5. O2 codes also. Replaced sensors. Any help is greatly appreciated
 
Did you use OEM parts, sometimes that's the issue when your replacing parts and still the same problem.

Dirty broken grounds is another common problem, along with the junk Factory battery clamps.

How many miles on the Engine?

If I remember right 1,3, and 5 are on the same side of the engine so maybe the harness going to those cylinders for the injectors.
 
Champion plugs Omni spark wires. Orielly lifetime coil pack 112000 miles. Bosch o2 sensors. Going to check grounds have not messed with injectors
 
Champion plugs Omni spark wires. Orielly lifetime coil pack 112000 miles. Bosch o2 sensors. Going to check grounds have not messed with injectors

I doubt if all 3 injectors would go bad like that, i'm saying could be the wiring harness that comes from the ECM. There should be a ground I believe in that harness for the injectors.
 
I doubt if all 3 injectors would go bad like that, i'm saying could be the wiring harness that comes from the ECM. There should be a ground I believe in that harness for the injectors.

Any ideas or places to start to check that. Code or misfires is po300 if that helps
 
Found the braided ground totally rotted of down at the block. Now I need to find the other end and reconnect. Hopefully this solves the problems

Since you had misfires on the same side, this was my first guess - so glad that you found it.

The strap goes from the back of the block to the firewall near the battery, and also to the hood. I found a replacement for mine on Amazon.
 
Since you had misfires on the same side, this was my first guess - so glad that you found it.

The strap goes from the back of the block to the firewall near the battery, and also to the hood. I found a replacement for mine on Amazon.

Well I am stumped. Can anyone tell me where the braided ground attaches to
Let us know.

well I am stumped. Can anyone tell me where the braided ground attaches to

IMG_0149.jpeg
 
My guess it would either go to the frame or the body.

Where do the 2 cables go to that are where the nut and big washer is to the left of the broken strap?