I have been having issues with car not turning on once in a while. it would crank but would not run. So, I thought that was the Crank Positioning Sensor. I replaced it. While at it, I also installed the Belt Wrap Kit. The belt that came with the kit was really tight but I figured that is how it was.

I now turn the car on, sometimes it does not turn on (similar to previous symptoms) but when it does turn on and I start driving, if I slammed the gas pedal or go over like 30-40 miles, car stalls. I can turn the car on, drive slowly and seems to not have any issues if I drive under say 30-40 miles.

could this be caused by the belt kit or I did not properly install the CPS? I checked the screw and it is pretty tight so I am not sure.

any help is appreciated.

ps. this is for 2006 e55

 

does the car throw any codes? have you checked your fuel rail(carefully, engine is hot) for fuel pressure? a BWK wouldn't cause the car to stop running cause of a tight belt, i would think it would shred the belt first. Also, you could've got a bad CPS depending on the brand.....

 

The best thing you can do is have someone hook it up to STAR, and read any faults.

Without knowing your level of mechanical expertise, it is difficult to quantify statements like "belt is very tight". The belt should be tight, but you should have no issue at all detensioning it. Do you remember the part number for the belt? What kind of pullies are you running? Post a pic of the position of the tensioner.

It sorta sounds like a supercharger issue. can you manually turn the supercharger?

It is unlikely, but possible that you changed the CPS with a defective one. Again, Star will tell you this. Is your CEL on at all? If so, you need to read the code.

 

I put the BWD brand CPS from Advanced Auto Parts.

http://shop.advanceautoparts.com/p/b...osition+sensor

if the belt is off, super charger turns fine. When the car is idling, supercharger and all the other belts turn very smooth. it is actually running a lot smoother then it ever did.

I wonder if a loose CPS connection would act like this? car had CPS error code before I did the replacement. I believe it was P0335.

 

Yes, no doubt everything is turning fine when the supercharger clutch is not engaged. Try to spin (by hand) the SC by the black drum right behind the pulley.

 

Should I take the belt off while doing that?

the issue is, I never had a problem with the super charger. I only changed the belt yesterday. before that, car just would crank but not turn on. Thats why I am leaning towards a faulty CPS sensor.

 

No need to take the belt off (unless you have a fixed pulley). just try to turn the drum. should take two seconds.

 

Not sure why you would use anything besides an OEM part here. Bosch CPS parts are cheaper than what you paid for the BWD ... not saying that that's your issue necessarily but cars have been known to run strange with non-OEM parts

This is what I bought and it works perfectly:

 

Also - do I have to do anything else to the car after replacing the sensor? I read some people saying you have to rev it up to 3000 RPM for 20seconds. I did not do any of that. any how, I found a bosch one in a local store, I will pick it up and install it tonite to see if that solves the issue.

 

No on these cars you don't have to "sync" them just plug in and go.

 

Also - if one side of the clip that goes on the sensor is broken, can I replace the cable as well. I will check that tonite to make sure it is all in one piece, but I heard those are fragile as well. if the cable is not sitting tight, would it cause this behavior?

 

SOLVED - It was a bad CPS that I bought from AdvancedAutoParts. I purchased a Bocsh CPS from another local part store and Beast is roaring again.

Lessons Learned - always use OEM, and dont buy important $#RF from advancedAutoParts.

thank you very much for all your replies.

 

Seems a few guys lately have gotten bad aftermarket cps that works but under load they stall or misfire

 

Glad you got it sorted out ... I always try to use OE parts especially on timing components wherever possible. Oxygen sensors can also act up if not using OE (both are my experience on other cars).
Best not to take risks on these or it could get expensive.

I only put aftermarket upgrades on... especially when there is a known weakness (for example pullies on our cars - best to go with billet and Airmatic suspension - Arnott gives limited lifetime warranty.)

 

Just for future reference if you ever need a MAF don't even think about anything but a Bosch. Others may be cheaper but you will be buying a new one within 6 months.

 

The 55k doesn't have a maf sensor. They have a map sensor. In this instance it was a crank position sensor

 

While not MB, reasoning is the same

https://m.youtube.com/watch?feature=youtu.be&v=-lUYRqaYvYI

 

We dont have that "voltage bias" in our engine right? We can use aftermarket O2s ?