2007 cls550 m273 intermittent misfire over a year
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2007 cls550 m273 intermittent misfire over a year
I'm going insane. My 2007 cls550 with 130,000 Miles has been having an intermittent misfire for over a year now. I'll get a p0300 and a p0306. It will idle rough but drive fine. I've replaced the #6 cyl sparkplug. The coil. And recently the fuel injector. I thought the injector fixed the problem because it went 28 days and 600 miles after that before I went out and started the car and it was idling rough. Checked the codes and same thing . 0300 and 0306. Such a ler down. It usually goes a few days without issue then boom the rough idle and codes come back. She has plenty of power and no issues while driving. I haven't bothered checking compression because I figure a problem with compression wouldn't be intermittent and I'd feel some sort of power loss. To me this seems maybe electrical.
Since it's giving me a 0300 along with 0306 does that mean not just the number 6 cylinder? My scanner is one of those orange launch creader bi directional scanners. I'm trying to see if I can find the fuel pressure readings son the scanner.
Anyhow anything else I should be checking. Lke i said after replacing the injector it went 600 miles and 28 days without issue out of that mileage there was 2 one way trips of 90 miles. The rest of the miles during that time was multiple in town driving.
A lot of times when it's idling rough if I just shut the car off and back on na couple times it goes back to idlling smoothly.
I just wish if would mess up and stay messed up and give me more of a direction to investigate.
Since it's giving me a 0300 along with 0306 does that mean not just the number 6 cylinder? My scanner is one of those orange launch creader bi directional scanners. I'm trying to see if I can find the fuel pressure readings son the scanner.
Anyhow anything else I should be checking. Lke i said after replacing the injector it went 600 miles and 28 days without issue out of that mileage there was 2 one way trips of 90 miles. The rest of the miles during that time was multiple in town driving.
A lot of times when it's idling rough if I just shut the car off and back on na couple times it goes back to idlling smoothly.
I just wish if would mess up and stay messed up and give me more of a direction to investigate.
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07 CLS550
What brand of ignition coils did you use? Bosch or OEM are the recommended options. I've had several cars come in with cheap aftermarket coils installed and misfires still present. Swap them out with Bosch and bingo bango no misfire. You can also try a fuel system cleaner. I run liquimoly fuel treatment through my CLS every so often.
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What brand of ignition coils did you use? Bosch or OEM are the recommended options. I've had several cars come in with cheap aftermarket coils installed and misfires still present. Swap them out with Bosch and bingo bango no misfire. You can also try a fuel system cleaner. I run liquimoly fuel treatment through my CLS every so often.
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07 CLS550
I've narrowed the problem down to the injector not getting signal to work. I'm in the price of trying to determine if it's wiring or the ECU. just yesterday I was checking the wiring and couldn't find anything. ingot a little frustrated and started violently shaking the wiring harness connections and gave the ecu a couple slaps with my palm at the same time and then restarted the car "after so long of it misfiring it ****s that cylinder down. until the car is shut off and then restarted.". when I restarted the car after shaking wiring and slapping the computer it went back to purring like a kitten. im sure I. a day or two it will go back to not sending impulse to that injector. next time I'll shaking the wiring really hard.bwfoew slapping the ECU and see if it goes back to normal. im hoping it's wiring and not the actual ECU.
We use a company for ecu repair and testing called ecu pro. If this isn't your only mode of transportation then that might be a good option. Doing a wiring overlay isn't the end of the world but tracking a break in the harness can be a pain in the butt.
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I was just reading about them last night. I would assume if it's the ecu it would stay broken and not intermittent. I took the car to a euro shop last week and paid them to diagnose it hoping they would find the problem. the apparently sick because they suggested tearing the valve train apart. it wasn't til I said no and took the car home misfiring that I unplugged the injector and noticed zero difference in sound or vibration while misfiring. then I used a node light and found the problem. pisses me off I paid a shop that couldn't even find that. if it is the ECU does ecu repair or do they just suggest replacement clone?
