platt-deutsch

CEL light on. Scanner says random misfires on 1 8 9 and 12. Reset CEL and it started. Drove a mile or so and CEL back on. Drove 40 miles shut it off and it wont start. Cranks fine but wont fire.
Bad fuel? Plugged Inj.? Plugs have 45,000 miles on them. Mileage is 108,000.
Any Ideas would sure be welcome..
Gary

IngenereAMG

My guess would be multiple coil pack failures.

cameraman123

Sounds like coil packs, is it trying to fire or just cranking? Could be CPS and coil packs

platt-deutsch

No firing.. just cranks..

s5benzo

yea either coil packs or crank position , crank sensor would cause it not to start but then again with 4 cylinders showing misfire it might be a safety feature where it wont start the car.

platt-deutsch

It finally coughed up code po 440 and 441 Cam Shaft Position Sensor. A circuit.
I wonder if anyone here has ever replaced one of them. Looks like the intake manifold will have to be lifted to get to it..?? Looks like a kind of bad job..Any suggestions..
Thanks
Gary

the shem

I had that prob on my 01 designo, car would not start when there was a chick in the car lol. my inday had the car for a month driving it himself, car never died. I pick the car up and take my chick out and it dies. just cranks, no fire. after 20 mins cars ok. My indy came out and changed the sensor in the jack in the box parking lot, never pulled the intake manifold tho. took him like 20 mins prolly different on a v12.. hope this helps

tusabes

common failure item, very simple repair on the v8s aodnt know about the 12

caddy

i have a 07 s550..
with the same problem its not starting ....its cranking but not starting..
its out of warranty so need help..
i have a benz mechanic and he cant even figure out the prob.
we change the crank shaft sensor...still nothing..

cameraman123

I'd try the W221 forum...

If your Mercedes-Benz mechanic can't find whats wrong with your car, get a new mechanic.

The CPS caused issues with the W220s but who knows if the same problem persists in the W221.