I have a 4104 with a 671. Even after pulling, cleaning. and graphite lubing my throttle cable I started thinking about air. When I bought my parts bus, it had an air throttle on a 671, so I remove it and installed on my bus. I now have perfect throttle response. I love it. We have driven 4000 miles since the conversion with no issues. Shifting is much improved, especially downshifting. I have one small issue. The engine used to start instantly - like no cranking whatsoever. Now I have to crank it for about five seconds, wait about 20 seconds then hit the starter again. It usually starts after the starter motor gets the engine up to the max rpm's the starter can turn. I'm thinking the injector rack has been reset following conversion and there's not enough fuel getting to the engine on startup. This is a Williams system. Is there some sort of idle setting at the throttle / engine connection? Once running it idles just fine, and warm restarts are quicker, but still not instantaneous like before. Thanks for any advice you have to share.
Sounds like you might be loosing prime. Usually when the engine starts for a short time, then have to crank it again, loosing prime usually is the reason.
If you have air pressure, just give the engine some gas pedal to start. I know on my Caterpillar (totally different kind of governor-full rpm type), the difference in just turning over the engine to start, and giving some gas pedal is unbelievable. The engine can be sitting for weeks, and giving some gas pedal starts with two compression strokes. Good Luck, TomC
Thanks Tom, I'll give it a try.
Does it seem to take longer for the engine to completely stop now when you kill it ?