All of the flow in the return line is due to fuel that leaks past the injector body & it's a very small leak. The leak is intentional & is designed to lubricate the injector.
You are correct that the pressure setting affects the way the engine runs but the pressure setting affect the spray pattern. Higher pressure = faster spray from the injector nozzle = better atomization of the fuel. Thanks, Tom Hargrave www.kegkits.com 256-656-1924 -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of dave walton Sent: Sunday, August 12, 2007 11:15 AM To: Mercedes Discussion List Subject: Re: [MBZ] thoughts on diesel clatter All the flow through the return line is the result of pressure drop AFTER the injector fires, right? My direct observation has been that the same injectors set to different release pressures affect the amount of clatter. I have been assuming that is due to the timing difference. Am I wrong? -Dave Walton On 8/12/07, Tom Hargrave <[EMAIL PROTECTED]> wrote: > You have forgotten some important points. > > I don't know how fast your arm is but the down stroke on my pressure tester > is probably 100 times slower than the delivery stroke on at diesel IP at > idle & the delivery stroke speed only gets faster as the engine RPMs > increase. Plus on a tight system, the injector line is already at the > pop-off pressure from the last cycle. This means that delivery starts the > moment the IP piston port closes regardless of spring tension. You have to > re-build pressure with every stroke of your tester. > > Thanks, > Tom Hargrave > www.kegkits.com > 256-656-1924 > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > On Behalf Of dave walton > Sent: Sunday, August 12, 2007 10:32 AM > To: Mercedes Discussion List > Subject: Re: [MBZ] thoughts on diesel clatter > > The more pressure exerted by the spring in the injector, the more fuel > pressure it takes for the injector to fire. It takes more Time to > develop higher pressure. Time = Timing. > > Hook an injector up to a pressure tester, change the shims and see for > yourself. > Am I missing something? > > -Dave Walton > > On 8/12/07, Tom Hargrave <[EMAIL PROTECTED]> wrote: > > Timing is 100% controlled by the IP & the injector is just a poppet valve. > > > > Weak spring pressure affects the spray pattern, not the injection timing & > > this causes the clatter. > > > > Another failure is a leaking injector which can leak fuel into the > > pre-chamber during the intake stroke & cause nailing. > > > > Thanks, > > Tom Hargrave > > www.kegkits.com > > 256-656-1924 > > > > > > -----Original Message----- > > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > > On Behalf Of dave walton > > Sent: Sunday, August 12, 2007 4:27 AM > > To: [EMAIL PROTECTED]; Mercedes Discussion List > > Subject: Re: [MBZ] thoughts on diesel clatter > > > > My experience has been that diesel clatter is caused by weakening of > > the spring in the injector. That causes it to fire at a lower > > pressure. Eventually it injects the fuel so prematurely that it > > ignites while the piston is still on the upstroke. > > > > -Dave Walton > > > > On 8/11/07, John M McIntosh <[EMAIL PROTECTED]> wrote: > > > Well since my 500SEL is busy having a rebuilt transmission installed > > > I was forced to cart four people across the rockies up the Coquihalla > > > Highway 5 to 8% grade for nearly 3000 feet of altitude in the 92 > > > wagon. For reference the OM603 will only do 75 mph flat out up the > > > 8% grade, water temp rose from 85C to 100C. That and another 500 > > > miles of mountain driving and 250 miles of flat land. > > > > > > After all this my wife noticed the clatter is *much* louder at idle, > > > much more clatter/bearings bouncing/burbling kinda noise. > > > > > > I wondering if I knocked loose lots of carbon (mind our normal > > > driving over the last 40K miles has been highway), and it's causing all > > > this racket? Well that or blew a exhaust gasket (don't think so) or > > > muffler joint. > > > > > > PS Saturday night in a unnamed rednecked city, never seen so many > > > chipped dodge ram 3500s. When they stomp the throttle at the > > > intersections, billowing clouds of black diesel smoke, same on the > > > highway, mind at 80 mph it's lots of roar and smoke, not much > > > acceleration, no need to check blind spots you sure can hear them. > > > > > > John > > > 1983 300TDt 385k Kilometers (mobil 1 Delvac) > > > 1990's 300TDt 202k Kilometers (mobil 1 Delvac) > > > 1993 500SEL 194k Kilometers (mobil 1 Delvac) > > > > > > > > > > > > _______________________________________ > > > http://www.okiebenz.com > > > For new parts see official list sponsor: http://www.buymbparts.com/ > > > For used parts email [EMAIL PROTECTED] > > > > > > To Unsubscribe or change delivery options go to: > > > http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > > > > > > > _______________________________________ > > http://www.okiebenz.com > > For new parts see official list sponsor: http://www.buymbparts.com/ > > For used parts email [EMAIL PROTECTED] > > > > To Unsubscribe or change delivery options go to: > > http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > > > > > > _______________________________________ > > http://www.okiebenz.com > > For new parts see official list sponsor: http://www.buymbparts.com/ > > For used parts email [EMAIL PROTECTED] > > > > To Unsubscribe or change delivery options go to: > > http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > > > > _______________________________________ > http://www.okiebenz.com > For new parts see official list sponsor: http://www.buymbparts.com/ > For used parts email [EMAIL PROTECTED] > > To Unsubscribe or change delivery options go to: > http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > > > _______________________________________ > http://www.okiebenz.com > For new parts see official list sponsor: http://www.buymbparts.com/ > For used parts email [EMAIL PROTECTED] > > To Unsubscribe or change delivery options go to: > http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com > _______________________________________ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com _______________________________________ http://www.okiebenz.com For new parts see official list sponsor: http://www.buymbparts.com/ For used parts email [EMAIL PROTECTED] To Unsubscribe or change delivery options go to: http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
