A meter can be used to verify that the reed is getting a signal & it can also check the coil but a meter can not verify the condition of the reed itself.
Tom Hargrave www.kegkits.com ----Original Message---- From: E M <[EMAIL PROTECTED]> Sent: 07/18/07 09:51 PM To: Mercedes Discussion List <mercedes@okiebenz.com> Subject: Re: [MBZ] 300e fuel issues. . ?? -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= I'd also be interested to know how to hook up a meter to check the reed. I recently bought a multi meter that reads dwell, but still learning how to use it. Ed 300E On 18/07/07, Troy Kocher <[EMAIL PROTECTED]> wrote: > > On 7/18/07, Tom Hargrave <[EMAIL PROTECTED]> wrote: > > > > There is a control pressure actuator attached to the side of the fuel > > distributor. A steel reed inside oscillates up and down, controlled by > the > > computer. Feedback from the oxygen sensor modifies the reed duty cycle. > > The > > duty cycle of the oscillation determines the control pressure to the > > bottom > > of the fuel distributor because the duty cycle changes the amount of > fuel > > that's allowed to pass through. The control pressure determines the fuel > > mixture. If this reed fails, as it did in one of my 300E's (twice, both > > times cracked), strange things happen because the system is no longer > > stable. It can stick open, stick closed or just not oscillate. > > > > If your fuel pressure is correct then I'd suspect this part. > > > > I'll talk to my mechanic about checking the fuel pressure. > Is there any way to determine the condition of the reed? > > > And Mitch is correct, the system does flow a lot of fuel. They do this for > 2 > > reasons. The first reason is that they actually use hydraulic pressure > > generated by the fuel flow, plus restriction (a pressure regulator), to > > control the system (mentioned above) and to do this, they have much more > > fuel flowing through the system than needed to maintain a steady control > > pressure. The second reason is to keep the fuel cool. The car would not > be > > running if you had a blockage in the tank, etc... > > > > Some have one fuel pump, some have 2. Both of my 1986 300E's had one. > > > > Earlier CIS systems did not a control pressure regulator. They depended > > entirely on the balance between the air flow sensor plate and a > calibrated > > internal spring to manage fuel flow. > > > > Thanks, > > Tom Hargrave > > www.kegkits.com > > 256-656-1924 > > > > > > > _______________________________________ > 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
