E6 350 idle adjustment

[mackone]

Was wandering where the idle adjustment is on a 1989 Mack E6 350 ? Idles a little to low, Thanks,Denny

[Joey Mack]

its on the injection pump. the throttle lever rests on it.  Ambach pumps have a 3/4" ish long, 5/16" jam nut with a flat head screwdriver head, in the center, Robert Bosch has a a 10mm jam nut on a screw that is 8mm-(5/16")  I'm guessing you have an Ambach... What I have done is remove the whole screw and clean it up really good, (I expect it to be stuck)... look at how the screw is set, so you can put it back together close to where it was. you can use the tach as a guide,  what i have used in the past, is a hand held photo tach and a strip of reflective tape on the harmonic balancer, something like the d.o.t. tape on a trailer, (white color). I have done enough of these where I pretty much can hear when it's good enough. not rocket surgery, just set it between 600-700...  There will be more opinions on this, but it is simple to do.  the long screw around the flat head screw is the jam nut. you turn the flat head until you like the idle speed then lock it down.. do you have an engine brake on the engine? 

[mackone]

O.K. Thanks Joey Mack, mine is the Ambach injection pump, yes it has a engine brake.

[Joey Mack]

is the engine brake switch on the firewall, with the throttle bell crank? assuming it's R or RW....  if so, you should be able to adjust idle without affecting the engine brake switch adjustment..  No biggie...  the switch is easy to adjust, just may have to twist yourself up like a pretzel to get to it...😉