W124 cold start problem

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Marjanov

Member
Joined
Jan 3, 2020
Messages
31
Location
Yeading
Car
Mercedes W124
Hello all,
Please help me to solve cold start problem on W124.
Mercedes W124 230E 1992 year(K) engine code 102.982
Cold start.First start after 8 hours on the drive way.Outside temperature is 20 C (summer time) Cranking too long when engine start after 3 seconds everything is fine and you can drive or rev the engine no problem.
Cold sart in outside teperature 5 C (winter time) Cranking shorter before start but still no good.
OVP is new both blade 10A fuses on the top of OVP are new.
There is ABS light before engine start then disappeared as should be.
In outside temperature (summer time) I did disconect cold start valve before cold start and there is no differents.

Thank You
 
Check out all you vacuum pipes and rubber joints they do split or break. Next is check all fuses replace if white metal.
When did you last replace distributor top rotor arm along with ht leads and spark plugs ? Do this and it 90 % of the car you can now forget about .And i bet you that you will find it will fix the problem .. Other item that can cause it is the iac valve you can remove it and clean it out with white spiris.Make sure all the vacuum hoses going to it .. and the engine.. are good condition and in place .
 
Check out all you vacuum pipes and rubber joints they do split or break. Next is check all fuses replace if white metal.
When did you last replace distributor top rotor arm along with ht leads and spark plugs ? Do this and it 90 % of the car you can now forget about .And i bet you that you will find it will fix the problem .. Other item that can cause it is the iac valve you can remove it and clean it out with white spiris.Make sure all the vacuum hoses going to it .. and the engine.. are good condition and in place .
Vacuum pipes and rubber joints checked.l did order From Germany Bosh Spark plugs,high performance ignition leads,distributor cap and distributor arm.
Today cold start(after two days)outside temperature 19 C and its same story.Cranking too long before engine start.Once it starts idle speed is fine it drops on 700RPM and l can rev it or drive it same moment but now at working temperature if l want start engine it start (just touch key)but cuts off then second time just touch a key and running and everything is fine.
Please let me know what to do next.
Thank you
 
Leads must be none resistor type,, also the plugs,, what is the number on your plugs .This might help you . Remove auxhliary ait valve clean it out with carb cleaner or white spirits .Mind the vacuum pipes on the rear .Make sure you fit them back where they came from after .CIStroubleshooting.jpg
 
Leads must be none resistor type,, also the plugs,, what is the number on your plugs .This might help you . Remove auxhliary ait valve clean it out with carb cleaner or white spirits .Mind the vacuum pipes on the rear .Make sure you fit them back where they came from after .View attachment 98674
Sorry its me again.
Please tell me is this what 1593619141525.pngI need to find under the bonet and clean.
 
rotary motorised idle control valve- it will bridge/bypass the throttle plate on the intake via 2 pipes - its 12V supplied via the OVP Relay and controled by the engine ECU
 
Auxhiliary air valve cleaned.
The rubber hoses Checked.
Cold start outside temp.14 C it starts with no cranking as it should be.
I was so happy till next day afternoon.Cold start outside temperature 19 C and cranking too long.
What is next?

Thanks
 
Have you changed the fuel filter and fuel accumulator under the car beside the fuel pump ; if the accumulator has failed it will cause exactly this trouble as you lose fuel pressure in the system when the car is standing . The accumulator is meant to keep the system pressurised . Sounds like your few seconds cranking is the time it is pumping fuel and priming the system again .
 
Are you giving the fuel system time to pressurise? How long do you wait after ignition switch on before cranking? the fuel pump assembly has a spring loaded accumulator designed to maintain fuel pressure after the pump has stopped- it maybe faulty-meaning a cold system needs to pressurise first before attempting to start.
Derek beat me to it! ;)
 
Have you changed the fuel filter and fuel accumulator under the car beside the fuel pump ; if the accumulator has failed it will cause exactly this trouble as you lose fuel pressure in the system when the car is standing . The accumulator is meant to keep the system pressurised . Sounds like your few seconds cranking is the time it is pumping fuel and priming the system again .
Thanks
 
Does it mean this is View attachment 99022View attachment 99024what l need to change?

Thank You
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Does it mean this is View attachment 99022View attachment 99024what l need to change?

Thank You
your fuel pump package is going to look something like this- the green arrow is pointing to the accumulator
pic02.jpg
 
I wanted this morning to go under car and check OE numbers but can not due to weather.
I did checked internet for electric fuel pump,fuel filter and fuel accumulator but please have you got any suggestions where to buy those for reasonable price.
What is reasonable price for each item?

Thank You
 

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