When the air temp is cold (<35-40 degrees) the car starts fine. If it gets above 45-50 degrees and the car sits for more than 15 minutes after being run and brought up to operating temp, the car won't start on the first 3-4 tries unless you depress the gas pedal. Then when it does fire up, it runs rough for 1 minute then smooths out. Other than this one problem the car runs great The MB dealer just did the 60k service 2 months ago (plugs, filters, fluid changes, etc.) and has replaced the following parts since; fuel pump, coolant temp sensor, gas cap, & a vacumn line. They can't find anything in the MB TSB's about this problem and suggested that we start replacing components, beginning with the fuel injectors, in hope of finding the problem. It's Christmas and all that, but I don't want to fund an expedition to rebuild what seems to be a perfectly good C220 other than the one hard starting problem. Has anyone else had a similar problem and if so what was the cure?

Have u put in gas in the car recently from a gas station that u don't normally use?

Let's start with the simple things....

First check the voltage of your battery.....one way to do it is with the on-board diagnostic system on you A/C control .....or actually using a voltmeter......or guestimate by turning the car off ..leaving the headlights on...if they dim a bit after a minute or less the I would first get it looked at.......

Second, It could be dirty gasoline......I recommed you put in one of those gas treatment products at less than half a tankfull drive it around for day and then fill it up....and drive it until its quarter full ...then refill as usual ........make sure u always use 91 octane or higher if available.

Next I would look at plug wires ....change em (only about 90$..and it is a 15 minute job)......

Check to see if your wiring harness is in good shape...if any wires are dry...there is a good chance there might be an iternal crack...remove the black platic small cover on the front of your engine...most of the wires should be visible under it ...check if anything is loss or damaged.

You may also want the car diagnosed by a star diagnostic system. Maybe there is code registered there ..which will save u time and money.

When your car is on and idling...try tapping lightly on your MAS sensor ....and report any symptoms you observe.


Is your idle smooth ...or does it fluctuate..up and down ......also ...does your car experience any loss of power while driving..and if it does does this happen while accelerating, t steady speed......


Finally Don't wanna scare you but.....the most it could be is ......first a bad throttle control ..therefore you throttle body has to be changed (750$ part)....or worst case senario you ECU is bad...

Glad to help out......let me know what happens...with you ..I am just over a similar problem ....which magically got resolved on its own......maybe it was bad gas...that is my only logical explanation..

"the one and only Mafiose"

I purchased this car about 3 months ago and it only did this occasionally, but it has become worse and worse since I took it to the local MB dealer. They have (so they told me) checked every component and replaced all of the faulty ones. There are no codes, no warning lights, they drained the fuel tank (no water or dirt) they ran industrial strength cleaner in a tank of fresh gas. They have had the car on and off about two months of the last three months. They've put about 200-250 miles on it, trying to find the problem. They say the OVP is good, they say the wiring harness is good, they've replaced the fuel filter twice, they replaced the plugs when they did the 60k service. The car starts fine and fast idles when it's cold, air temp that is. You drive the car and get back in it after only 10-15 minutes it starts great. Let it sit for 15-60 minutes it won't start unless you crack open the throttle about half way then when it does start it has a rough idle for about a minute like it had a miss or was flooded, but it doesn't blow any black smoke or smell of gas. I think it's some part that is being affected by temp above 50 degrees under the hood. The coolant temp doesn't seem to make any difference. It could be a wire making intermittent contact on the air temp sensor or it could be in the cold idle enrichment valve or the ECU. The local MB techs are at a loss. I've ordered a Haynes book for the UK, maybe it'll help. Wirhout schematics and specs I'm only guessing and was hoping someone else on the web had had the same problem and could give me some insight. Other than this one problem everything else about the car is excellent, runs and drives great, as good as my 2000 c230, just a little less power from the c220. Thanks for the reply.

The last things replaced were the wiring harness and the wiring to the coils. The wiring harness was the first thing suspected, but everything looked good to the eye and the local MB dealer said it was OK. However in the course of replacing the fuel pressure regulator the cover was removed and the insulation was falling off of the wires and many were bare. The car starts and runs great now and I hope it stays that way for a long time.

The fuel regulator may be leaking (hole in the diaphragm). Pull the vacuum line with engine running. If it’s spitting fuel replace regulator internal. Simple procedure and need C clip compressing pliers.