Thought: Uber cold engine, plus cold fuel, combine to slow down the combustion flame path, so the fuel air charge which is ignited via compression heat ignition, burns more slowly and less completely as it drives the piston down.
Some of the fuel / air charge remains in the cylinder throughout the "power stroke" and continues to burn during the exhaust stroke. Th*is prolonged burn has the effect of altering the timing, so the engine is "running against its self, thus runs poorly.* *As engine temp rises... the combustion of fuel becomes more rapid, and "timing" becomes "normal". thus engine runs as expected.* *Early on diesel wisdom given to me was to always warm up the engine before putting it under work load... * On Fri, Dec 29, 2017 at 7:43 PM, Scott Ritchey via Mercedes < mercedes@okiebenz.com> wrote: > Different start problem scenario: I started my 82 SD (617 turbo) this > a.m. for its annual trip to NC vehicle inspection station Temps were low > teens overnight and probably mid 20s when I started it. Battery minder > (usually on) was disconnected before start attempt. Engine had not run in > weeks and probably only drove 50 miles in last year. I haven't been > driving the car because I need to replace the flex disks (procrastinate, > procrastinate). > The old engine started instantly but.. the whole car shook hard at idle > although it smoothed out with just the slightest acceleration. After > driving about 10 miles the engine idle was almost normal (just slight > diesel shake). > Why did it shake so bad at cold idle? Any theories? Too cold? Hard > engine mounts? Could the engine dampers be frozen? Maybe a wonky injector > that wouldn't seal, spray, or meter right at idle? The shake was more > violent than my earlier experience with bad glow plug(s). > Any thoughts? > > > _______________________________________ > http://www.okiebenz.com > > To search list archives http://www.okiebenz.com/archive/ > > To Unsubscribe or change delivery options go to: > http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > > _______________________________________ http://www.okiebenz.com To search list archives http://www.okiebenz.com/archive/ To Unsubscribe or change delivery options go to: http://mail.okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
