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Old 04-16-2003, 09:53 PM
Rogue Rogue is offline
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Join Date: Mar 2003
Posts: 16
Name That Mistune

Hello JBoggs. By spitting back, I was referring to erratic timing -- kinda like the old Chevy spitting back thru the carberator when the timing was off. Many times when the secondary coil windings have a small open, the coil will discharge erratically; thus, sending a pulse down a plug wire causing a cylinder to fire at an inopportune time and cough or spit back thru the intake if the valve is open. doesn't sound like you've had that problem. While the Haynes manual is relatively useless, the section on ignition diagnosis is very applicable. Use a volt/ohm meter & perform the indicated tests for the coil & ign. control. Another option(suggested) is hook engine up to a scope & observe test patterns & total coil output. From your reference to very weak color voltage from coil wire, that to me indicates low coil voltage. Before you condemn the coil, make sure that the coil is getting sufficient voltage. A coil receiving low voltage cannot provide max voltage to the plugs. If so equipped, make sure the coil over pressure(read high heat) pop-up has not popped up. And as Neil suggested, check your vacuum lines for leaks. Finally, all suggestions assume that you have maintained the car in good operating condition. I'm sure you have but I had to say it. If budget allows, go to a service center for a written diagnostic; otherwise, get your vot/ohm meter. On my 190E the diagnostic connector is on the inner fender panel.
Personally, I still suspect a dirty fuel filter or faulty fuel pump/relay. My 2 cents.
Keep us posted :-)
P. S. Almost forgot, voltage regulator. On my 190E the voltage regulator brushes are housed in the rear of the alternator. I have not worked on your model(read cannot afford, wish I could), check your manual. The brushes and/or brush holder are easily replaced. I actually bought a decent alternator off of ebay & carry it as a spare, complete with new voltage reg. If the voltage reg ever fails, you Will be stranded as The Benz is dead! Easy insurance other than the belts a B*tch :-(

Last edited by Rogue; 04-16-2003 at 10:05 PM.
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