Difficult Starting - W124, E280
Thread Starter
Newbie
Joined: Jun 2002
Posts: 22
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From: London, England
E280 W124 1995 24V
Difficult Starting - W124, E280
Can anyone help?
My W124 E280 has become difficult to start from cold, but only occasionally. Four times out of five it fires up first turn of the key - regardless of temperature or dampness - provided I do not touch the accellerator (gas) pedel.
Maybe one morning a week now (and getting more frequent) it refuses to fire. I have to turn and turn the engine over for a number of minutes until eventually, by applying about threequarters throttle, it stumbles into life - running very roughly for thirty seconds or so - thereafter it "clears it's throat" and runs perfectly.
My car is well maintained and runs perfectly otherwise, continuing to give very good MPG.
Any expert out there who can advise me what might be wrong?
It's not let me down yet, but I'm worried that, in the future, the battery will give up before I get it started.
Thanks, Doug
My W124 E280 has become difficult to start from cold, but only occasionally. Four times out of five it fires up first turn of the key - regardless of temperature or dampness - provided I do not touch the accellerator (gas) pedel.
Maybe one morning a week now (and getting more frequent) it refuses to fire. I have to turn and turn the engine over for a number of minutes until eventually, by applying about threequarters throttle, it stumbles into life - running very roughly for thirty seconds or so - thereafter it "clears it's throat" and runs perfectly.
My car is well maintained and runs perfectly otherwise, continuing to give very good MPG.
Any expert out there who can advise me what might be wrong?
It's not let me down yet, but I'm worried that, in the future, the battery will give up before I get it started.
Thanks, Doug
MBWorld Fanatic!
Joined: Aug 2002
Posts: 1,005
Likes: 32
From: Germany
'00 S320 W220, '98 A160 W168/ sold in 2005 '86 260 E W124 '90 260E W124
Hard to tell, but just a few simple and DIY things you can do:
*check the spark plugs (distance and cleanliness)
*check the spark plug and the ignition coil cables for nicks and holes in the insulation
*the the plugs of the cables, all cable sitting sound in the plugs
*check the air filter
*check all the vacuum hoses whether they are conneted properly
*check the intake assembly and the valves whether they "bypass" air, by taking off the air filter, let the engine idle and spray alcohol (starter fluid or break clean) on each valve, and all the hoses and the intake assembly. If the idle speed goes up during that procedure at any given spot you sprayed, uncontrolled air (in the test case additional fuel) enters the engine and increases idle speed.
more elaborate and to be done by a shop is to check the fuel pressure. If all this does not lead somewhere it may be one of the temperature sensors and starting valve(s) which caused random problems
*check the spark plugs (distance and cleanliness)
*check the spark plug and the ignition coil cables for nicks and holes in the insulation
*the the plugs of the cables, all cable sitting sound in the plugs
*check the air filter
*check all the vacuum hoses whether they are conneted properly
*check the intake assembly and the valves whether they "bypass" air, by taking off the air filter, let the engine idle and spray alcohol (starter fluid or break clean) on each valve, and all the hoses and the intake assembly. If the idle speed goes up during that procedure at any given spot you sprayed, uncontrolled air (in the test case additional fuel) enters the engine and increases idle speed.
more elaborate and to be done by a shop is to check the fuel pressure. If all this does not lead somewhere it may be one of the temperature sensors and starting valve(s) which caused random problems
Member
Joined: Jan 2002
Posts: 184
Likes: 1
From: Montreal, Canada
260E , 1989 (for now)
The previous post has covered a lot of ground in explaining possible causes to your problem.
I would add: The problem could be related to the fuel accumulator. This device keeps the fuel system pressurized when the engine is stopped. When operating properly, the fuel accumulator insures there is already fuel in the line at start up.. With a defective fuel accumulator, the fuel in the fuel lines returns to the fuel tank as soon as you stop the engine. Could be a reason for a cold start problems.
These car should, if in top shape, start from cold very easily.
It was minus 28deg. this morning. I have a remote start gizmo and within 2 seconds, my car started as if it was 75deg.
It is supposed to be even colder tonight (minus 34deg) and my Benz will start with half a turn of starter tomorrow morning.
Good luck
jackD
I would add: The problem could be related to the fuel accumulator. This device keeps the fuel system pressurized when the engine is stopped. When operating properly, the fuel accumulator insures there is already fuel in the line at start up.. With a defective fuel accumulator, the fuel in the fuel lines returns to the fuel tank as soon as you stop the engine. Could be a reason for a cold start problems.
These car should, if in top shape, start from cold very easily.
It was minus 28deg. this morning. I have a remote start gizmo and within 2 seconds, my car started as if it was 75deg.
It is supposed to be even colder tonight (minus 34deg) and my Benz will start with half a turn of starter tomorrow morning.
Good luck
jackD
Newbie
Joined: Jan 2003
Posts: 8
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From: Central NJ
1986 300e
dont use brake clean, use carb cleaner
Brake cleaner doesn't cause the rpm surge that starting fluid or carb cleaner do. Plus it attacks caertain kinds of rubber (ever get any on your latex gloves?).
Greg
Greg
