jimdvfd

I have a 2002 ZR600 EFI that runs great when cold. After it warms up the low RPM range starts to sputter. If you get the RPM above 6,000 it goes great. If you let it run long enough the servo will open and close at idle like it is quivering. Per the service manual the servo should not open until 6,000 rpm. I have cleaned the power valves, adjusted cable lengths. I have two of these sleds so I swapped the computer and servo with no change. The LED doesn’t give an error code. Any ideas on where to go next?

kccats

Air temp or water tem sensor! The servo is just cleaning itself??? But if one of the sensors is off then the engine maybe thinking it's still cold and keeps adding extra fuel (like the choke is on)!

jimdvfd

If the air temp or water temp switch were bad why is the LED on the computer not telling me there is a bad sensor.

kccats

There is a way to go threw self diag, but I,m sorry I did it once on my Pantera but don't remember how to get it into that mode! There are resistance tests for that though!

jimdvfd

I took a meter and both the air and coolant temp sensors check out. I unplugged the coolant sensor and it did flash an error code on the ECU. Reading another tread about quitting after getting warm that the stator could be the problem. I have heard that where problems with the stators. Is 2002 one of the years that they had problems. If so how do you test it