300 E very very hard to start only when cold - PeachParts Mercedes-Benz Forum

Ron in SC · #1 11-01-2008, 06:41 PM

1992 300 E engine is very, very hard to start only when it's cold. Once it does almost start it stumbles and dies. When it eventually does finally start it will idle fine.

Starts fine when warm or hot. Always idles fine and does not stall.

I have two 1992 300 cars so I've so far swapped out OVP and MAS sensor. Plugs, distributor cap and rotor, filters all seem fine.

What might I try next?

hfmscan · #2 11-02-2008, 07:18 AM

check word cold start valve... voltage in cold start on valve

Ivanerrol · #3 11-02-2008, 10:43 AM

Accumulator - near fuel pumps and fuel filter in rear.

troylatif · #4 11-02-2008, 02:40 PM

I second the accumulator. Depending upon how long you can go without it giving the quirky starting behaviour, you should know how big a leak it has. Mine had a pinhole size leak and caused the engine to spin at least 10 times to start on a cold morning.

-Troy

Ron in SC · #5 11-02-2008, 05:04 PM

Quote:

Accumulator - near fuel pumps and fuel filter in rear.

That may be but this engine was doing the same thing in the car I removed it from before I put it in this car. Both cars are 1992, one a 300 E and the other a 300 TE.

How can I test the accumulator?

babymog · #6 11-02-2008, 07:12 PM

Possibly coolant temperature sensor?

pawoSD · #7 11-02-2008, 09:50 PM

This is the kind of stuff that makes me leery about buying a 300E.....

babymog · #8 11-02-2008, 09:59 PM

The old CIS-E cars ('91 and older?) are pretty simple, and will most always run if the fuel pump and ignition works, sometimes it is getting it to run well that can be challenging. Problems are relatively few and easy to chase using a test light, good DMM, and resistance substitution box.

The later 104 cars though, a lot more parameters affect the engine's health, including its many self-protecting and limp-home features.

pawoSD · #9 11-02-2008, 10:01 PM

Quote:

Originally Posted by babymog

The old CIS-E cars ('91 and older?) are pretty simple, and will most always run if the fuel pump and ignition works, sometimes it is getting it to run well that can be challenging. Problems are relatively few and easy to chase using a test light, good DMM, and resistance substitution box.

The later 104 cars though, a lot more parameters affect the engine's health, including its many self-protecting and limp-home features.

Thats good to know. I guess I know who to go to when mine isn't running right.