John deere 455 Questions

[dconrad246]

Have a John deere 455 i am trying to get tuned up. The engine rpms are about 300 to 400 low and am trying to fix it. Already adjusted the governor and the valve lash but no change. what else do i need to look into? I have an issue with starting right now in that it starts hard but runs fine and starts fine once its warmed up, replaced the glow plugs and that made it better but didn't fully fix it. just wondering what i am missing and what else to check. wanted to try and get a service manual but cant find one for less than $300.Thanks in advance for any help.

 

[Kish318420]

Have you looked at the throttle and cable area?

 

[dconrad246]

yes, the cable is maxed out. the bracket was a little bent so bent it back and there is no more travel in the whole thing. I also tightened up the Fuel solenoid mechanism as well because that was a little loose. idle rpms are also low as well, but that i think i can adjust with the bolt on the throttle mechanism to bring that up. more concerned that the high end is low, the rpms on the front pto are 300 short as well and it is affecting the 60 inch deck cut quality. Plus with winter coming i want the power for the broom to work properly.

 

[Kish318420]

What RPM are you shooting for on the diesel?

 

[dconrad246]

i think the manual i found said around 3200. Unless there is something i am missing to up the pto rpm.

 

[dconrad246]

now that i look the specs say 3350 rpm and i am at 2900. rpms on pto are 1800

 

[Kish318420]

I would try running some Seafoam (or your favorite fuel/engine cleaner additive) to clean the injectors, valves and combustion chamber. It should help the injector pump also. It will take a few tank fulls. Have is the fuel filter/air filter?

 

[dconrad246]

Swapped the filters and did full fluid changes when i got it. that was about 40 hours ago. ran some seafoam through it (Probably in a bad way) and it didnt help yet. will try again and see if there is a difference. I ended up shutting off the fuel then filling the fuel filter bowl by the engine about a quarter to half full of seafoam then ran the engine for about a half hour at full throttle. will try again and see if it helps.

 

[Kish318420]

You'll blow your engine that way!! Just put it in the fuel tank and also in the oil. VERY IMPORTANT: FOLLOW DIRECTIONS on the can for diesels!

 

[dconrad246]

So, still no change. (Ran the seafoam correctly this time) then double checked the valve lash and that was correct. Tried adjusting the governer again and noticed it was basically maxed but I am not getting black smoke like I believe I should at this point. What else is there to check? I am thinking fuel pump but don't think it would be running right at all if that was the case. Hoses aren't pinched anywhere that was the next thing I checked. Any other ideas?