cabinman73
New member
- Joined
- Feb 28, 2021
- Messages
- 1
- Tractor
- John Deer F935
Hello. I have a question regarding this motor. The john deer manual says compression should be 355psi with a max. of 71psi difference between cylinders. I see all sorts of numbers tossed around as to minimums but nothing official. Does anyone know what would be considered ok and bad?
I also have another issue, this unit ran poorly, very rough idle, hard starting so I started with new injectors. I bought them from China but I suspect more of them come from there no matter who sells them. During the switch, one cylinder was missing the injector cip/shield, one was intact and one was missing the entire end so it was doing nothing ( weird ). In any case I had new ones, installed them and then the unit ran worse, a lot more smoke, I was shocked so I pulled them. I did a compression test, roughly 260-280 with 6-7 revolutions on each test. Warm or cold, doesn't make a difference, lots of smoke. My next move will be to take those injectors in and have them tested. One of my biggest concern is this fairly distinct metalic ticking sound, not the kind you get from valves, I did check and verify those are at .007" which is within spec (.006- .008"). I am definitely frustrated. Anyone have any words of wisdom ?
I also have another issue, this unit ran poorly, very rough idle, hard starting so I started with new injectors. I bought them from China but I suspect more of them come from there no matter who sells them. During the switch, one cylinder was missing the injector cip/shield, one was intact and one was missing the entire end so it was doing nothing ( weird ). In any case I had new ones, installed them and then the unit ran worse, a lot more smoke, I was shocked so I pulled them. I did a compression test, roughly 260-280 with 6-7 revolutions on each test. Warm or cold, doesn't make a difference, lots of smoke. My next move will be to take those injectors in and have them tested. One of my biggest concern is this fairly distinct metalic ticking sound, not the kind you get from valves, I did check and verify those are at .007" which is within spec (.006- .008"). I am definitely frustrated. Anyone have any words of wisdom ?
