Hunting

[edhopwood]

Hello folks, A while back I posted about my engine surging or hunting. At the time I thought that my engine had a Pnuematic governor but after a look at some online manuals and from very useful help on here it seems it's a mechanical governor. The pump is Simms Mimimec on a pre-1957 Industrial Engine.
The engine hunts a little on idle and under load at certain RPM's, there's actually a couple of sweet spots where I'm running it and they'll be stable revs but don't have a tachometer so not sure exactly where this is.
A few questions if I may:
how worried should I be about this? it's never stalled under load but the sound of it can be a little disconcerting.
I have a diesel specialist nearby so can get the pump off and serviced but obviously if there was any checks I could do myself ( or an engineer) I'd like to try that first.

all the best Ed

[edhopwood]

Also, somebody who has experience of these pumps mentioned they can suffer wear in the Tufnol Coupling (?) and this could be the cause of the issue. I'd be very interested to hear other's opinions.

Ed

[Brian]

If the pump is the one on your engine picture in "Misc" it is not a Minimec it is an early mechanical governor. The Minimec, as its name implys, is a much smaller pump that did not come out until the very late 1950's and was not used on Ford engines until 1962.

Hunting is not a problem unless it gets very bad, a lot of diesels do it on low revs. Your pump is an industrial unit and not common, I will check what data I have and post with your original post.

[edhopwood]

Thanks very much for the help again. I can also take some more photos of the pump if that will help although it sounds like you already have a good idea of which one it is.

Ed

[edhopwood]

Somebody suggested inspecting the lift pump to see if it's clean etc.
Maybe thats worth a try too?