drewsome2

Lots of problems here - I'll start at the beginning. Car had rough idle and poor gas mileage - changed out MAF sensor, seemed to do the trick. Started back with engine stumbling and dropping out while idling. Discovered a bunch of fuses blown - Check Eng lite fuse blown - replaced fuse, Check Eng lite came on. OBD scan returned codes for EGR valve and O2 sensor Bank 2 Sensor 1. Before I could replace, Eng lite went off - fuse blown again. Replaced fuse, same trouble codes. Replaced EGR valve. Checked OBD again - returned no codes, but still had drop out while idling in gear. Drove about 10 minutes and car completely cut off and wouldn't restart. Thought it was overvoltage protection relay, so replaced that. Car turns over but acts like not getting spark. Hooked OBD scanner up - no trouble codes. Ideas?

Blk04cobra1

fuel pump relay? or fuel pump fuse?

C43AMG

CPS - crank position sensor

drewsome2

Wouldn't CPS throw a code? What are other symptoms of CPS? Tried to start using ether but engine wouldn't throw a spark.

C43AMG

No, won't "throw a code".The symptoms are - giving impression of "flat spot" on the starter - turn key.....nothing , try again...slight turn of motor....try again..she starts.The other "symptom" - you'll love this...the car shuts off while driving down the road.You pull over, wait a few minutes and she cranks like nothing was wrong.

drewsome2

Does the CPS just "go" or is it more gradual? Car died while driving, tried restarting, left it sit for about 15 minutes, tried to start again, turns over but no start. Left it sitting all day, tried to start, engine turns over but won't crank.

C43AMG

Interesting question.If you are ultra-**** (like me),you'll notice it as a "gradual" thing.Maybe once every 2 weeks I had to crank it twice to get it to turn over.If you're not....it will happen "all of a sudden".My big concern is that it can "go" and the motor just shuts off,creating a dangerous situation.

drewsome2

Yah, that's exactly what happened, not a fun situation to be driving one minute and coasting the next! Is this a DIY fix, or a take it somewhere fix? Thanks so much for ALL the info!

C43AMG

Sensor - about $100.00...maybe 1/2 hour to do...depending upon your mechanical ability.

drewsome2

Awesome - you are a wealth of knowledge!

C43AMG

Let us know how you make out!

StapleGun

C43AMG beat me to it - but yeah, sounds like the CPS is gone...classic symptoms of it, at least.

Jons95c36amg

How many miles on your car?

drewsome2

110K.

UPDATE: Had it towed to the mechanic. ECM is smoked. Faulty wiring harness is what they think caused the blown fuses and smoked the ECM. Now having fun trying to find an ECM for the AMG.

SDR

Yeah ... this sounded more like a wiring problem to me. Aren't the 36's prone to problems there? I now my buddy's C36 had a disgustingly decayed harness when we opened it up. He was popping fuses once a week and couldn't figure it out.
As for the CPS, has anyone ever had it stall while really driving? In my experience it was only when at or close to idle. Embarassing as hell to have to push yourself out of an intersection, but better than suddenly dying in the fast lane.

C43AMG

That's a damn shame.There's no reason in the world that a wiring harness should fail.

Jons95c36amg

Getting my wiring replaced soon when it comes in. It was a whopping $1400!! The c280 was 800. Car runs like a champ but better safe then sorry.