1989 560SEL - Engine issue
 

Okay so here is my issue....

My 1989 560SEL with 162,000 on the clock has all of a sudden decided to start running on less than the 8 cylinders is has. I replaced 2 plugs that appeared to be badly fouled. All the others are fine. Over the past year he (yes, my 560's name is Hans) been running a little rough when cold then fine when fully warm.

In the past 2 months its as if the car is doing something worse than just rough idling. It's like the engine like wants to die, or being starved of fuel, or something. When he's fully warm its like the engine jerks and has now a cylinder or two not firing, even at highway speeds.

Am I having a fuel flow problem? Injection issue? Any or all thoughts or questoins are welcome.

Thanks!!

Do the cap, rotor & wires check out Good?
Have you checked compression?

So many possible reasons......

Start off looking for vacuum leaks. Check injector O-rings and cups. Check the air distro hoses. Check the air intake plenum, and the ring seals underneath all that intake stuff.

Check your cap, rotor, and wires (actually might wanna do that first). Make sure that the injectors for those cylinders are working. You may have a dying fuel distributor (god forbid).

Lots and lots of possibilities. Start off with the easy to check/cheap to replace items.