Thank you in advance for any insights. your forum has been quite helpful, i have read throug all your posts (titles) about Dixies and have not found anything similar though. here are the details:
I picked up a couple Dixie Choppers. 2003 xt2800 and a 2004 sp2800 both with CH745 Kohler EFI 28 HP. they have been sitting a few years so i cleaned the tanks and replaced the fuel lines, replaced filters on both machines and the XT runs great
However, the sp2800 will not go below 2600 rpm and tops out at the rev limiter at 4750 rpm. it will idle down to about 1400 rpm if i hold the butterfly closed, or run the throttle in a negative throttle position. i.e release the throttle cable and push the throttle past the low idle stop.
i have replaced the fuel pump, and throttle linkage.
the TPS OHM's are within spec and vary according to throttle position
The speed sensor ohms are about 940 cold (78 degrees), but i noticed they were 1245 slightly warmed up. the kohler service manual doesn't say anything about higher temperature so i may spend some more time on it... spec is 750-1k for room temp
i have swapped ECU's, both bosch 32 pin., same results
adjusted the governor to bosch spec as well as a little high and a little low as the linkage would allow. The governor appears to move and regulate the engine, but the overall rpm's are just to high
i have tried to run the TPS initialization procedure... it will never complete, almost like it never reaches "closed loop" operation. i put the jumper in, start the mower, it goes to 4 blinks on the MIL, i pull the jumper, back off the throttle, move the idle screw and it will either stay on 4 blinks or go to a fast blink but never any further.
The mower does not have any MIL codes except 61
Dixie is not a common mower in Colorado, but i have found a couple Kohler Dealers...not really my style unless all else fails though.
My next steps:
Swap or unplug O2 sensor, seems to be a comoon issue, but not with the same symptoms
Swap TPS from the xt to the sp
compare and or swap speed sensors from the xt to the sp... not sure how buried it is in the motor though
swap intakes.
try to adjust the governor in discrete increments. all the way up a little lower a little lower etc.
learn more about the injectors perhaps they are stuck wide open or something, but it does not smoke, stutter or foul plugs...it runs like a champ
I could almost adjust the throttle to a negative position and bend the stop plate out of the way to make it work, but that pushes the control arm into the governor and creates a bind in the linkage
it just seems more like there is just a sensor or ground wire or plugged intake vent... just something that i don't know about...I am just looking for some people to bounce ideas off of.
Please let me know if you have any ideas. Thanks
I am new to posting so hopefully i did this correctly...
I picked up a couple Dixie Choppers. 2003 xt2800 and a 2004 sp2800 both with CH745 Kohler EFI 28 HP. they have been sitting a few years so i cleaned the tanks and replaced the fuel lines, replaced filters on both machines and the XT runs great
However, the sp2800 will not go below 2600 rpm and tops out at the rev limiter at 4750 rpm. it will idle down to about 1400 rpm if i hold the butterfly closed, or run the throttle in a negative throttle position. i.e release the throttle cable and push the throttle past the low idle stop.
i have replaced the fuel pump, and throttle linkage.
the TPS OHM's are within spec and vary according to throttle position
The speed sensor ohms are about 940 cold (78 degrees), but i noticed they were 1245 slightly warmed up. the kohler service manual doesn't say anything about higher temperature so i may spend some more time on it... spec is 750-1k for room temp
i have swapped ECU's, both bosch 32 pin., same results
adjusted the governor to bosch spec as well as a little high and a little low as the linkage would allow. The governor appears to move and regulate the engine, but the overall rpm's are just to high
i have tried to run the TPS initialization procedure... it will never complete, almost like it never reaches "closed loop" operation. i put the jumper in, start the mower, it goes to 4 blinks on the MIL, i pull the jumper, back off the throttle, move the idle screw and it will either stay on 4 blinks or go to a fast blink but never any further.
The mower does not have any MIL codes except 61
Dixie is not a common mower in Colorado, but i have found a couple Kohler Dealers...not really my style unless all else fails though.
My next steps:
Swap or unplug O2 sensor, seems to be a comoon issue, but not with the same symptoms
Swap TPS from the xt to the sp
compare and or swap speed sensors from the xt to the sp... not sure how buried it is in the motor though
swap intakes.
try to adjust the governor in discrete increments. all the way up a little lower a little lower etc.
learn more about the injectors perhaps they are stuck wide open or something, but it does not smoke, stutter or foul plugs...it runs like a champ
I could almost adjust the throttle to a negative position and bend the stop plate out of the way to make it work, but that pushes the control arm into the governor and creates a bind in the linkage
it just seems more like there is just a sensor or ground wire or plugged intake vent... just something that i don't know about...I am just looking for some people to bounce ideas off of.
Please let me know if you have any ideas. Thanks
I am new to posting so hopefully i did this correctly...