FordManiac
Member
I have looked into this before but still need help. I have both a Ford 4600SU and 4000SU. Strangely enough they both have had the same issue but in slightly different ways. The problem is the engines both run ruff at certain rpm ranges. So I started running a Opti-Lube cleaner and fuel additive in both of them. Magically the 4000 totally cleared up and runs perfect now. But the 4600 is just getting worse. Originally it ran ruff a 1600-1800 but now most of the whole rpm range is rough. I just replaced injectors but only improvement is at idle. Less smoke at idle now but no change otherwise. Could the pump be the issue? Engine is in great shape and cranks on a dime in cold weather. This tractor has less than 2000 hours on her.
Thanks[/list]
Thanks[/list]