Hi just trying to help a lady with a brokedown C240, she was driving battery/alt visit workshop came on the went off several times, got off freeway car died, restarted went 100ft then died and won't restart battery checks good touched valve on fuel rail found squirt of fuel when pushed and already replaced crankshaft sensor at back of drivers side bell housing. Not sure what else to chase, it cranks just fine but doesn't start please help!!!

 

My car did the same thing she may need a new battery.. I was driving by the beach side left my fog lights on while i was on the phone talking for about 30 mins.. Car barley started.. Drove around for another 10 mins pulled over to talk on the phone again.. This time i left my flashers on and my fog lights.. 10 mins later i go to start the car and all i hear is this CLICK. Car wouldn't turn over Waited for AAA to get a jump.. They hooked up a battery charger to my car and that worked for 2 hours until i got home. Came to find out that night i had a bad cell in my battery and it wouldn't charge anymore..

Read the voltage before cranking and read the voltage when trying to crank the car. Come back and report on that.

 

The car cranks just fine the battery tested good there is something that's causing no spark I think? There is no ck engine light on or
malfunction

 

Battery or alternator failing or both is still possible. Get the battery load tested or replace. Try a careful jump start. No sparking etc. You can blow a SAM.

Can also be plugs, wires or coils but give it a go with a fully charged healthy 100 Ah battery. Sometimes these cars even battle to start with a jump if the battery is lazy.

You have checked fuel rail pressure which is positive so pump is operating. You do not know whether she is injecting or if the pressure is adequate. When last did the car have a fuel filter? Fuel pressure regulator is built into the filter. You know the CPS is good but check the connection.

I think that the ignition is down on power so try the electrical side first.

 

turnover no start is one of 3 possibilities- PCM, fuel, spark.

check those and go from there.

 

The battery and system was checked by mercedes roadside said it was ignition related. Just not sure what else could cause a no start, maybe camshaft sensor?

 

Well it cranks great, there is fuel at rail pressure valve. So that rules out fuel and pcm and crank sensor, as far as I know if there is a crank sensor issue or pcm issue it won't turn on fuel pump but that is ok, I did notice a 15 amp fuse that was blown which I switched with another fuse not sure what it was cause her fuse box card is missing

 

checck the cms, coils, plugs.

it can only be 3 things.

 

use all data or shopkey to find out what that fuse is for.

 

What is cms? I removed the cam sensor at RF of engine and found a lot of sludge oil gunk on cam sensor I wiped clean and reinstalled but still just crank
s

 

cam sensor

 

When was the CPS replaced? Always check the last thing fiddled with. This is very typical of CPS. Do you have spark? & remember that compression suppresses spark but at least check one plug

 

I havnt checked for spark and I just put in the cps last night she got a cam sensor today and I will put it in tomorrow. Ill post as soon as I know. I did notice some on the cylinder 2 or rf coil pack area

 

Please explain this? You noticed what? Sparks jumping through insulation to earth ???

 

yeh confused by that

 

BTW - another suggestion - Please get hold of an OBDII scanner & check for stored codes. The plug is under a rectangular cover under the steering column. It might save a lot of guessing & trial & error.

 

^ valid point.

 

No codes in system and what I meant earlier was there is oil around rh valve cover front coil pack I would think it would cause misfire though not complete no start?

 

shot in the dark but the exact same thing happened to my truck the other day! ended up being the mass air flow sensor, cleaned it up and been fine ever sense.