Originally Posted by
Bowhunter/Ranger519vs
All grounds were checked and we put a new grounds on coils 2,4 and 6. Still didn’t change the results. Is there one ground for the coil plate? If so, if the ground was bad wouldn’t that affect the right bank as well? I know the left bank and right bank are both grounded to the plate, is there another ground that I’m forgetting about?
Not always, Right bank and left banks have their own separate ground circuits. I would recommend a voltage drop test on the ground ckt. Volt meter connected to the black wire at the coils and the ground test lead connected to the battery ground where it is attached to the motor, check this drop while the motor is being cranked. Any reading on the meter is undesirable voltage drop, up to one volt would probably not be a problem
Grounds can cause some really strange issues.
Might be wise to also drop test ecm power and grounds as well
Report back please