Engine lope at idle

Hi,
suggest first check the actual Low Idle Speed you have as anything much below the spec. of 550 RPM could cause instability--lope--it may be beneficial to run it at around 575 RPM and up to 600 RPM and see if it smooths out.
Cheers,
Eddie B.

The lope is all governor.......the fuel pressure variation will be in response to the rpm change .....not the other way around.

It is basically a result of wear in the governor components that leaves a little slack and makes the rack move very easily. That's not to say that the rack shouldn't move smoothly, but with some wear in the governor components that hook to it, you get the lope.

I have a 9U D6 that has a very responsive governor.......it lopes. On the old ones, it may be better to have that???

Thanks guys. The rack and pumps were stuck when I first bought it so I did quite a bit of lube work to get them moving freely. I’m going to find a tach and then check the rpms relative to the throttle indexing and see if I’m just setting it too low.

In addition to fixing your t-stat I hope you are taking it out and working it at temperature to keep the wet stacking from returning. I wonder how many machines have had the engine overhauled to fix the wet stacking only to see it return when they only play and idle. Working them with a load at governed RPM is our friend keeping them running as they should.