Cam or Crank Position Sensor??? - Benzworld.org

srfox · 08-30-2007, 07:16 PM

My 98 E320 started stalling randomly while driving, and then not restarting for hours. Up until tonight it always happened somewhere convenient.

Coming from a BMW background, my first thought was to replace the CAM positioning sensor on the FRONT of the engine, which I did. Car ran fine for a couple of days, but stalled tonight big time in traffic and just arrived home on the back of a flatbed. I suspect it will start fine tomorrow but no way am i taking it anywhere.

So now do I replace the CRANK positioning sensor on the BACK of the engine?

BTW no codes, no CEL. Turns over awesome, won't fire.

Steve
98 E320
02 G500
00 M5

Kajtek1 · 08-30-2007, 07:34 PM

Does tachometer move when you crank?
It might be either CPS or fuel system. Did you test fuel pressure on the rail?

srfox · 08-30-2007, 08:16 PM

Quote:

Originally Posted by Kajtek1

Does tachometer move when you crank?
It might be either CPS or fuel system. Did you test fuel pressure on the rail?

I'll check the tach in the morning, but as I recall it did not move. Thanks!

Steve

srfox · 08-30-2007, 08:50 PM

Update: two hours after the tow truck left, the car started right up without me doing anything to it.

Are MBs secretly made in England by British Leyland?

Steve

ohlord · 08-30-2007, 09:54 PM

R/R seems to be in order,no codes it is failing.Multi meter could check it out but I don't have the resistance value,autohausaz.com,free shipping over $50.diy on this site,have a good flashlight it's dark down there,also put on gloves(latex)and watch out for the fender well heat shield(sharp)
ohlord
"GOT CODES?"

Totalfixation · 08-31-2007, 05:12 AM

I had that happen to me once, where it stalled on me, but was lucky enough that i was able to restart it right away. Best thing to do is to change the CPS. If it happens again i say change the fuel filter to see if it doesnt any improvement.

srfox · 08-31-2007, 08:31 AM

Car running fine this morning, at least in the driveway. I pulled the CRANK position sensor and the business end of it is scored a little, like it was in contact with something rotating. seems odd. ordered one from AZ AH, $50.00 cheaper than local dealer.

Steve
98 E320
02 G500

ohlord · 08-31-2007, 10:28 AM

Chip of metal,can all damage the cps.It is the nature of the beast in the environ it operates in.When you r/r make sure to treat the new one with care and also check the wires at the hook up.After install a dab of dielectric grease on the point where the wires plug into the sensor,will help displace moisture and heat,helping prolong the new cps.
ohlord

"GOT CODES?"

srfox · 08-31-2007, 10:58 AM

Quote:

Originally Posted by ohlord

Chip of metal,can all damage the cps.It is the nature of the beast in the environ it operates in.When you r/r make sure to treat the new one with care and also check the wires at the hook up.After install a dab of dielectric grease on the point where the wires plug into the sensor,will help displace moisture and heat,helping prolong the new cps.
ohlord

"GOT CODES?"

Thanks, good idea on the dielectric.

Steve