W124 300CE 24V coupe engine misfiring

[macker64]

Morning folks,
Would appreciate your expert opinions on the following.

Yesterday afternoon I went for a spin in the 300ce (m104.980 engine) and she started to shudder/misfire when I pulled up to a set of traffic lights.

Stepped on the go faster pedal and nothing, no acceleration and the engine started to shudder/misfire big time.

Pushed it to the hard shoulder and switched off. Attempted to restart and again it fired up but was misfiring continuously!

Todate I have replaced the OVP, Reg pack on alternator and the battery by way of preventative maintenance.

I have attached a photo of what I believe is the CPS sensor which I understand can cause this misfiring. I measured it this morning and its open cct. I presume this is a hall effect sensor so the resistance reading is probably correct or is it?

Needless to say after 10mins rest she started right up and drove home without missing a beat.

Could the Distributor cap and rotor cause this fault?

I have checked the wiring to the throttle body and fortunately its ok with no sign of dis-integration!

Anyone experience similar symptoms?

Regards,

 

[robparker]

yea, dizzy cap and arm

 

[television]

As Rob I think, just wiping some PTFE all over the rotor arm and the inside of the cap can help on this

 

[rayhennig]

yea, dizzy cap and arm

Yes, I agree 100%.

It's worth checking all your HT components and DON'T go cheap. I know it's easy for me to spend your money but try to get original MB cap rotor and leads.

Failing that, in my experience, Bosch or Beru ONLY.

Oh and make sure you've got the ordinary copper plugs from Bosch, Beru or NGK. Anything exotic is a waste of cash and can cause problems. And any plugs with resistance are right OUT in a standard system.

To summarise, make sure your HT is 100% before getting morbid and thinking you've got some super-expensive problem.

R

 

[macker64]

Evening guys,
I have replaced the distributor cap and rotor arm on the W124 300CE and the engine fired right up and behaved itself on a test drive!!

Managed to source the parts from ebay Germany for 1/3 of the stealer price!!

Thanks to all those who replied to my initial request for help!!

Regards, ;-)