Nasty little Gremlin
 

Hello everyone. I haven't been of the boards much lately since the Benz has been running so well. Although lately it has developed a nagging little problem. It starts fine and runs good up until it gets good and warmed up. It will then begin to lose power and stumble. I can have the pedal to the floor and it will sputter, backfire and not have any power. I can reach up, turn the ignition off and back on and the problem disappears. the problem comes back of course but it could be a minutes to a few minutes later. I have dropped the tank, ran a good amount of Acetone through the tank then took it to the car wash and pressure washed the inside of the tank. Dried it out real good and reassembled the whole thing with a new filter. Problem is still there. I checked the ignition coil and the primary windings show zero resistance and the manual indicates .38 to like .4 ohms. Or something close to that. The Secondary windings show exactly what they are supposed to be. I will be replacing the coil in a couple of days. Anybody else have this issue? At one point i did read something online similar to this issue, but I am unable to locate it now. Any help with this problem would be greatly appreciated. Also, what upgrade can I use when replacing the coil? Whats good? Accell, MSD...etc
The car is a 1985 280SE. Damn good car imo. 165,000 miles

Looks like you need a new rear crank position sensor.

'reads zero' .... on which resistance scale ?

The 85 280SE has a crankshaft position sensor? No mention of that sensor in the service manual.