Engine Performance problem
1985 Mercedes Benz 500sel V8 Two Wheel Drive Automatic 150000 miles
Engine starts fine when cold or when it has been setting for 5 minutes or less after being warmed up to normal operating temperature. After about 5 minutes (when warm) it has to be cranked for 30 to 60 seconds before it will start. Other than this persistant problem, the 5.0L engine runs well for it's age and mileage. I love this old car but I sure want to find a solution for this problem. Thank you!
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March, 9, 2009 AT 11:50 AM
It is possible for hot start up problems to be caused by a flooded engine. This will definately cause what you are describing as you will usually see 30-60sec of crank to get the excess fuel out of the cylinders. This is usually caused by leaking injectors and can occur usually at higher mileages. You can check to make sure all are operating by placing a screwdriver on each injector and listening to the end of the screwdriver with the engine running. You should hear the injectors clicking on and off. If one is not clicking it can be either stuck closed or open (open causing a flood condition). Also even if the injectors are operaating one may just not be sealing causing a leak as well.
Also check your vacuum lines for any split or kinked lines. Often times on this vehicle in particular vacuum leaks can create havoc on this vehicle.
Are there any other issues you notice other than this. Any excessive crank any other time? Warnings in the cluster? Excessive fuel consumption? Rough idle? Lower top speed?
March, 10, 2009 AT 8:35 PM
Thank you for your informative reply. I will check the injectors as you suggested and let you know what I find. Now that you mention it, the engine does seem to idle rougher than it did in the past and it is somewhat sluggish in acceleration at low rpms than it used to be. I will also check for vacuum problems. I am not getting any warning lights and the gauges read normal. I really cannot tell about fuel economy since the odometer has stopped working. I also cannot really tell about top speed since 98% of my driving is in traffic around town. Many thanks for sharing your wisdom. I will get back to you as soon as I can.