1990 420SEL Starting Problem?

Plugs

Change the plugs. Wouldn't hurt to do all the filters too. Expect a slight milage increase if you do.

Hi John, my 89 300e started doing the same thing earlier this summer, it has not gotten worse. I've changed plugs etc etc to no avail... whereas it used to start with a turn or two, it now takes 4 or 5 sec cranking and once it starts everything is fine. Moreover, and this may be fortuitous, this is the first summer that the car apparently has suffered vapour lock - ie it took over 5 min or thereabouts of cranking befor starting/sputtering and then continuing fine. the only thing I've not checked so far is the fuel filter

best wishes, guenter

You are right about vapor lock when engine is hot. In your case it is most likely to be the fuel accumulator that is leaking... easily checked by pulling out the rubber hose and if fuel keeps dripping out, it is bad.

I suspect the same problem with the 420SEL... usually occurs when engine is hot... very hard start after 10 minutes (tThis however depends on how bad the accumulator is leaking)... In cold start, takes a bit longer to start.

Thanks for the reply.

The air filter is new. How many fuel filters are there? Where are they located?

John

Thanks for the reply.

I would suspect vapor lock, but it's the same cranking hot or cold.

John

I would change out the distributor cap... or at least clean the brass terminsals inside it... I kinda recall of this symptoms and it came up to the distributor cap.