1993 w140 missfire

[12.5EVO3]

Starts fine then as it warms it starts to miss then clears and runs fine. Any ideas?

 

[mikestrivens]

read this:

http://forums.mercedesclub.org.uk/showthread.php?t=119801

 

[12.5EVO3]

That sounds a bit worrying. How can test the MAF

By the way its a 5.0l v8

 

[Ben Longden]

My 92 W140 had an intermittent rough firing issue for some time.
Thought it was the MAF, but alas not.... even after STAR tests and reports.

Chugged into an experienced auto elec, and he had the problem nailed before I finished driving into the shop.

It was a new set of spark leads that was needed.

HTH
Ben

 

[12.5EVO3]

It does look like it has had a new set of leads, also the old ones are still in the boot.

 

[robparker]

Done the caps in the last year or 2? If not do them again, with bosch ones, they are bad on these engines especially if not driven regularly up to temperature and fail often