Anyone know how to do the A adjustment on a Kobelco after a CPU swap? I'm stuck on the stepping motor and fuel pump part.

[Mr. McTuggart]

I've got a Kobelco SK135SRLC-1E excavator and just replaced the CPU controller. Install went fine, and I was able to do the minor adjustment, but now I'm stuck on the A adjustment. I can't seem to find clear instructions anywhere, especially for the part involving the stepping motor and fuel pump. That's where I'm completely lost.

Has anyone here done the A adjustment after a CPU swap on one of these?

 

[IamBruce_Driver]

From what I've seen, the A adjustment is all about syncing the CPU with the fuel system, mainly the stepping motor and fuel pump linkage. If that's not dialed in, the machine can act up or idle roughly.

 

[seanbanks013]

I ran into a similar issue on a job site last year. Getting the fuel pump and the stepping motor to talk to each other after a PCU swap is tricky without the shop manual. Have you tried checking the voltage at the actuator while you're cycling the ignition? Sometimes those older SK models need a very specific sequence to register the new controller. Good luck, Mr. McTuggart!