My machine is a PC 150-5 1993 year model. I have noticed it starting at a higher rpm than I think it used to. After it runs for a few minutes at idle it drops a few rpm's. Is there something like a cold start system or could it be some type of sensor or other problem. I have not noticed it running differently or any other problems. Thanks.
When adjusted properly there is a warm up system built into the throttle control. The engine will run at about 1,200 RPM until the coolant temperature reaches about 100 degrees F. It will drop to the low idle speed once that temperature is reached.
i do not think it has any problem,first it will be high,then lower a bit,it is normal.
That is my favorite excavator of all time!Enjoy it!
Must have had your first cool morning. Colder it is the longer it will run fast, I believe. The 150-5 has an intake heater like a toaster coil in the intake manifold. Turn key backwards until the indicator turns off. Do NOT be tempted to use starting fluid after using intake heater. I've started ours in below 0 deg. weather, starts very well.
Thanks guys for the info. I figured it was supposed to do that but couldn't find any info on it in my operators manual. Here in Arkansas we very rarely get even into the teens for overnight lows but I have started this machine several morings in the 20's and used warmer then she fired right off. Bought this machine 2 years ago and have done very little repair, cylinders, hose.etc. She's got 7800 hrs and running strong.Thanks again.