Start up shakes

[thegoonerman]

Hi non mechanical newbie here could anyone help. I have a 95 w202 c200 elegance auto and when i start the car up for about 30 secs or so it shakes quite violently and the revometer jumps back and forth from 500rpm to 1000rpm.

 

[guydewdney]

service it? change plugs / filters etc lately? sounds like a duff spark plug to me - or if its a diesel (i assume not) then duff glow plug.

 

[paulcallender]

Sounds like an ignition problem, or rather a lack of ignition.

Pull the ignition lead off No 1 spark plug and start it. Then repeat for all the other cylinders so its running on 3 cylinders each time. Whichever cylinder makes it no worse, is the culprit (bad lead or spark plug).

Definitely worth having a look at the plugs, too. In fact, while you're there taking them out, may as well put new ones in?

 

[joe bloggs]

Cant do it with your engine, direct ignition coil system. get a dealer to run a star test, this should tell you which cylinders / coil is down.