Cold start is fine but after warm start the engine misses and sta

Diagnose Engine Misfire - Auto Diagnosis Repair Help

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The engine may shake so badly at idle that it causes vibrations that can be felt in ...The engine may only misfire and run rough when cold but then smooth out as ...

What is causing an intermittent misfire only when engine is ...

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Jun 27, 2013 - NOTE: You MUST restart the engine for the misfire to go away. ... in an expert to do that test, but it might be worth it to prove/disprove the injectors being thecause. 0 ... The first is that the car should run fine even on cold starts.

Engine misfires when cold but runs fine after warming up few ...

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Mar 24, 2009 - They also gave it to me because of this misfire problem it has. ...Engine misfires when cold but runs fine after warming up few minutes later? ... and you start next morning will also cause a misfire until it burns off the coolant.

"Miss/splutter" with cold engine, but fine when warm? M103 / also ...

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Jul 13, 2011 - My moms old 300SEL (with the M103) that was once my car is now my "work car" again as she is getting a brand new SUV very soon.

Cold start misfire solved (finally!) - Bimmerforums

Battery has full crank power?battery connection.

defintly a valve,regulator or gas line leak,or injector leaking rail pressure

Friend, you have a faulty temperature sending unit. Change THAT and you'll have this problem no longer. The temp sending unit, when cold, will put the engine, by the computer, into cold start mode, the engine starts getting a bit more fuel until is warmed up, then the sending unit tells the computer it's warmed up and shuts down the cold start mode. Only makes sense, Right?

Click on the following direct, free Link. It has several Belt Mark Diagrams for your 1990 Mercedes Benz 300 Class 3.0L V6. It also has additional - very helpful Instructional and Directional Diagrams.

Let me know if this helped, or if you have additional information or questions. Feel Free to contact me at FixYa.com!


http://www.2carpros.com/car_repair_information/year/1990/make/mercedes-benz/model/300ce/1990_mercedes-benz_300ce_drive_belt_routing_diagram.htm

It sounds like a fuel delivery issue. Mercedes recommends replacing the fuel filter every 60k. If it has been longer than thast since the filter change start there. Fuel pump relays are another common problem on this era. They are located behind the battery. Remove the plastic cover and you will se 2 black relays( yours may have a mass relay if it is a 90 model year, it will have a plastic knob on top that you turn to the left to unsecure it) IT will say kickdown on it the climate control is the other relay and it will say klima. Look for signs of corrosion on the solder pins. If your fuel pump(located at the right rear) is very noisy when it operates I wouild recommend replacing it. During this era of Benz about the only way to diagnose this would be to run a bunch of fuel pressure tests and to drive vehicle with a meter on the relay and on the pump to see if the relay cuts out or the pump cuts out. I always recommend to do both pump and relay because they can cause one another to fail. good luck.

well if tune up and normal maintenance is current I would guess its the cold start valve. When the valve starts to fail or fails it can allow the extra fuel used at cold idle to "flood" the system when its not needed when warm.

check engine coolant temperature when it gets warmer, or at operating temperature, and verify that the temperature gauge is showing warmed up to operating temperature. If the coolant temperature sensor tells the computer the engine is cold it will over fuel and miss and the engine will die. When cooled down it will run fine until it warms up. Also could be coil if it starts missing after warmed up.

i had same problem check the OVP fuse located behind the battery that were mine is i have a 1990 check were yours is at if the fuse is burnt all the electronics that help you engine run are inactive check it before anything the overload protection relay

Either the sending unit,(this unit is on the motor)is malfunctioning, or your engine oil pump may not be providing enough pressure.
This could be due to sticky oil pressure bypass valve,,worn out pump,,or worn engine main bearings.
If it is just a case of worn engine oil bearings,this is usually indicated by high oil pressure when cold,,but low oil pressure when hot,.i wouldn't worry to much, since most engines suffer from this same complaint and doesn't harm the engine any.