cold start problem m104 - PeachParts Mercedes-Benz Forum

jsmith · #1 02-18-2003, 12:18 PM

ref: '93 300E-2.8 M104 engine

this has happened to me on occasion a few times but this winter it has been fairly often. the symptoms only appear when it has been in the 30's (F) or colder and only when the car has been sitting for around 12 hrs or so - usually overnight. if it doesn't catch on the first couple of turns it will stumble and not start easily. after further cranking of about 4-5 seconds, it will catch, stumbling a little bit then smooth out immediately. subsequent starts will then be ok. i tend not to look at the OVP as the problem because it is a cold start issue. my search has not turned up anything aside from OVP and cold weather valves. does my car even have a cold weather valve? i am going to replace the fuel filter soon - is there anything else to check?

jsmith · #2 02-18-2003, 08:37 PM

bump...

this isn't normal is it?

J.HIDALGO · #3 02-18-2003, 09:40 PM

It could be a lot of things like leaky injectors, fuel acumulator, bad coil, etc.
Good luck!

jsmith · #4 02-19-2003, 07:40 AM

all symptoms go away after it starts successfully. still don't know if it has a cold weather valve - anyone?

#5 02-19-2003, 08:23 AM

Hi Jsmith.

I used to have a similar problem on mine. Now, when I start her up, I only turn the key to 2 switching on coil, electrics etc, and hold for about 5 secs - in the case of my car that also alows the seatbelt tensioners to finish travelling - but that is another story. Then I'd turn the ignition on to 3 and it would fire sup straight away.

jsmith · #6 02-19-2003, 12:32 PM

Neil,

I tried your procedure this morning and it seems to have worked! I still wonder what this is indicative of, and whether it is within normal limits of operation.

Cheers

GregS · #7 02-19-2003, 12:56 PM

Very possibly indicative of low fuel pressure. The system has a pressure accumulator (I believe located next to the fuel filter), which is supposed to maintain system pressure after the car has been shut off. If it isn't working, then system pressure is leaking down and isn't high enough to keep the car running when you start it.

When you turn the key, the fuel pump starts running, and if you wait a couple seconds you are giving it time to build up system pressure again and, voila!, the car starts and runs fine.

GregS
'84 300D
'90 300CE

jsmith · #8 02-19-2003, 04:02 PM

yeah i suspect the fuel accumulator as well. i'm getting a quote although i can live with the problem for now.

jsmith · #9 02-20-2003, 05:48 PM

just an update. replaced the fuel filter with Bosch high capacity fuel filter from fastlane and haven't had the problem so far. i found that the PO had already changed it previously since there was a Purolator filter in there.

checked with Phil our partsman - he found that my car did not appear to have an accumulator. i checked the performance products parts pages and the accumulators were indicated only up til '92. my manual does indicate that cranking up to 4 seconds is normal so maybe that was it after all...