Need help - C220 1996 engine stalls

[bpeter]

My C220 1996 (198K mi) starts fine. I can run the engine while in park (or driving), then the engine dies. When it occurred for the first time 3 days ago, it occurred while I was driving. The engine cut out and then a few seconds later it came back on. It happened about 3 times in a row. I was luckily able to get the car back home.
Here are the items that I already checked or replaced recently:
About 12K miles ago I replaced the following:
- Replaced fuel pump (original Bosch)
- Replaced fuel filter
- Replaced fuel pump relay
Here are the items I check today.
- Replaced spark plugs (they needed to be replaced anyway and they looked fine)
- Checked power to the fuel pump relay and the fuel pump. They both get power and I can hear / feel that the pump is running even when the engines starts stalling.
- Checked air filter (looked clean- it was replaced about 10K miles ago).
When the car dies, I may be able to to start it back right away or I may need to wait for a few minutes to get it started. Then it will run and after a few minutes the engine will die again. While the engine is running, it runs clean and has power if I want to move the car.
I am looking for ideas. I saw posts about CPS, air mass sensor…..
Any help our how to trouble shoot would be appreciated.

[Scary-Larry]

Peter,

Considering that you have looked over the fuel pump and the plugs, I think that it could be the CPS. I have had trouble with the MAF sensor and the CPS; the MAF just makes the performance vary and the CPS will stall the car from my experience.

I am unsure how you can test the CPS, but when mine broke...it was 2:30am in the center lane on the highway when only big rig trucks were driving. I was able to roll into the breakdown lane, but I was unable to start the car again. For months before the incident, my car would sometimes stall right after starting, but it was very rare and never while I was moving (except for that one night).

If you know about mechanics, then this might help:

http://mb.ilcats.ru/group/class/1/cc...02/subtype/022

http://mb.ilcats.ru/part/class/1/cco...retsubtype/022

http://mb.ilcats.ru/part/class/1/cco...retsubtype/022


In this case someone with a 1996 C220, same as your car, had a stalling problem and they discovered it was their CPS. They have some information on replacing it with photos:
http://www.benzworld.org/forums/w202...ensor-diy.html


I'm not sure if it will work on every car, but I read of someone figuring out that their CPS was broken by plugging in a scanner into the car (under the dash). I don't want to tell you it is the CPS and have you replace it and waste money to find that it is not the problem.

This video shows someone diagnosing the sensor in a different car (similar idea though); he uses an electric meter to see if the sensor uses the correct amount of current: http://www.youtube.com/watch?v=6ws8EVQ6NjE

If you diagnose it and find it is the case, these guys show how to change the CPS on an S500 (different engine, but the basics are in the same place overall): https://www.youtube.com/watch?v=KTTM3VeJuA8

I found the part here at a vendor that I buy some parts from: http://www.rockauto.com/catalog/x,ca...,parttype,7196
I am not the best mechanic, but I will do what I can to help you. Just diagnose that CPS before your car shuts down and won't start again.

Good luck, keep me updated. I cannot not think of anything else that it could be at this point, but if I think of anything then I will post it for you.

[taz069]

I'd have to go with the crank position sensor. If you have access to a volt-ohm meter it is pretty easy to check once removed. My old bosch had a ohm reading of 1.028 ohms. With this one in my car performed like a snail and would be had to start. The new bosch has a ohm reading of 1.046. That doesn't seem like much but to the computer it made all the difference in the world. I had to repull the new crank postion sensor due to some backfire and the car hard to start. It had the same reading but the crank had left some scuff marks on the little metal center post. I used my palm sander and smoothed it all off minus a couple of thousandth's upon reinstale VAROOM!!!! I guess after 16 years the die that bosch made my replacement with was just a hair off. Hope this helps.

[bpeter]

Here is an update about the car that may help others.
I checked if I can get access to the CPS sensor from above the vehicle. I was not able to access it from above. I checked below the vehicle and it looks like I would need to remove the starter and some elements of cruise control (there is another post with pictures detailing the removal).
The main two causes from various postings were CPS and MAF sensor. I decided to have a shop (not a dealer) that specialized in German cars run diagnostics on it since I did not want to replace the MAF sensor without knowing for sure it is the cause of the problems (and the CPS is such a pain to replace).
The failed part was the MAF sensor. They will replace it for the charge of the diagnostics ($80). The MAF sensor was $290 (remanufactured Bosch) which is about the same I would pay at autohausaz web site. I hope the above info helps someone else.

[taz069]

Glad ya found it. A 3/8 5mm allen, 3/8 swivle, 2-3' extension and the allen that retains the cps is at your fingertips! Done pulled mine multiple times. Yeah lost a lil skin reaching behind the oil filter pulling the cps out and reinstalling it multiple times more like 7-10 times. Just glad ya found it.

[bpeter]

One more update. When I read the codes using an OBDI reader that you get from store like Autozone, Pep Boys etc, the car did not show any codes. When the shop connected their computer, they saw the MAF sensor error code right away. They cleared the codes and the MAF sensor generated another code right away. I understand they also have to reset the computer (probably reset the value range settings for the MAF sensor ) when the new one is inserted. Are there consumer friendly (reasonable $$) options that would allow me to successfully read the codes at the level the shop did?

[taz069]

Sorry for the late reply. My lil 96 c280 is ob2. Your's might be also. My bud's scan tool works just fine on mine. It showed me all codes. Check for ob2 or ob1. More than likely ob2.