Temperamental firing or fuel problem?

[northcave]

Car: 1992 300 SL 12v

I've noticed that over the last couple of months the car has hard to turn over a few times before starting cold. Then also whilst driving it would judder slightly as though it mis-fired but only very infrequently.

The the other day it cut out all together on the side of the road. I got it started again and when reving it almost feels like someone left a spark plug out.

Anyway then i couldn't get it started for about an hour until it decided to work again but still slightly dodgy when driving and lack of power pulling away. At high revs it seemed ok.

I would put this down to a dodgy ignition or spark plug but even if 2 plugs decided not to fire, that wouldn't stop the engine from starting at all would it?

Any ideas? Fuel problem maybe or still ignition?

 

[kth286]

Take it to a Merc specialist and see if any fault codes registered.

 

[northcave]

urr if it were that easy i think this forum would be a little quiet. The nearest merc spec with a old style flash coder is a long way away.

 

[kth286]

So, where are you ?

 

[star]

check the distributor cap.

 

[northcave]

Update on this one. I took it out again and it is ok for the first 10 minutes... then it begins being juddery again. At higher revs it appear ok and if i drive slowly it helps keeping it in 2nd gear with the revs high. After about 25 minutes it warmed up fully and appeared ok...

Auto choke problem?

 

[star]

As above 1st.

 

[northcave]

Yeah sorry i just replaced all the ht leads and spark plugs, i'll go have a look at the diz cap now and get back to you.