Are these classic symptoms of a faulty CPS (Crankshaft Position Sensor)?
07-03-2012, 02:09 AM
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Are these classic symptoms of a faulty CPS (Crankshaft Position Sensor)?
So after not driving my car for an extended period of time, I usually have a pretty sketchy time starting and driving my car.
Most typically, while just simply sitting in idle, the rpm's will suddenly dip to the point where it almost dies out (sometimes it will just die out) and then the car tries to recover by bursting the RPM's back up to about 1.5K which makes for a very scary experience while in gear. Another symptom I've experienced is very sketchy start off's from a complete stop. I'll step on the gas pedal like normal, and the car will kind of give gas in bursts, like the fuel is cutting in and out. One last symptom significantly lagged throttle response, sometimes when either at a completely stop or applying gas after coasting, I'll step on the gas but the gas wont kick in til maybe a 1/2 second later, and when it does kick in, it a really strong uncomfortable jolt that probably isn't good for my engine mounts.
Anyone know if these symptoms are tell-tale signs of a faulty CPS (Crankshaft position sensor)? I was finally able to capture most of this on video so please check it out in the video below. Thank you.
http://youtu.be/wUAMs_Us32A the car sputters on acceleration at about 1:00 and then at the next stop just completely dies out. I restart the car and barely move 5 feet when it dies out again.
Most typically, while just simply sitting in idle, the rpm's will suddenly dip to the point where it almost dies out (sometimes it will just die out) and then the car tries to recover by bursting the RPM's back up to about 1.5K which makes for a very scary experience while in gear. Another symptom I've experienced is very sketchy start off's from a complete stop. I'll step on the gas pedal like normal, and the car will kind of give gas in bursts, like the fuel is cutting in and out. One last symptom significantly lagged throttle response, sometimes when either at a completely stop or applying gas after coasting, I'll step on the gas but the gas wont kick in til maybe a 1/2 second later, and when it does kick in, it a really strong uncomfortable jolt that probably isn't good for my engine mounts.
Anyone know if these symptoms are tell-tale signs of a faulty CPS (Crankshaft position sensor)? I was finally able to capture most of this on video so please check it out in the video below. Thank you.
http://youtu.be/wUAMs_Us32A the car sputters on acceleration at about 1:00 and then at the next stop just completely dies out. I restart the car and barely move 5 feet when it dies out again.
Last edited by walee112; 07-03-2012 at 02:15 AM.
07-03-2012, 02:31 AM
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While it could still be the CPS, it could also be an issue with buildup on the Throttle Plate
Read post #2 in the thread below, it seems this has happened to a few members here.
https://mbworld.org/forums/c32-amg-c...stall-fix.html
Good Luck!
Read post #2 in the thread below, it seems this has happened to a few members here.
https://mbworld.org/forums/c32-amg-c...stall-fix.html
Good Luck!
07-03-2012, 11:24 PM
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I had to replace my CPS a few months ago, for me it would just die and not let me restart. After a while it would start, then I'd drive a while before it would just cut out again later. I don't remmeber any idle issues...
07-04-2012, 01:24 AM
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I talked to my adviser today who is totally chill, and she said the symptoms sound similar to a Air Mass Sensor failure. Not so much symptoms of the Crankshaft Position Sensor. She said that symptoms of a failing CPS were similar to testknight's symptoms. Will Star diagnostic work since the check engine light isn't on? I'll also look into the throttle build up. thanks for the suggestion guys.
Last edited by walee112; 07-04-2012 at 01:43 AM.
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07-06-2012, 09:12 AM
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2017 GLE 350 Wifey, 2005 C55 AMG
exactly what he said, replaced my CPS a few months ago too
07-07-2012, 03:03 PM
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07-07-2012, 03:17 PM
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a car that can't do the throttle reset.
I talked to my adviser today who is totally chill, and she said the symptoms sound similar to a Air Mass Sensor failure. Not so much symptoms of the Crankshaft Position Sensor. She said that symptoms of a failing CPS were similar to testknight's symptoms. Will Star diagnostic work since the check engine light isn't on? I'll also look into the throttle build up. thanks for the suggestion guys.
07-07-2012, 06:15 PM
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2016 Chevrolet SS, 2006 Cadillac STS-V
I would clean the throttle body to start, mine was fairly dirty when I installed the supercharger at ~42k miles. If you're higher mileage than that, it could be really dirty. Plus, even if it isn't your problem, it won't hurt anything for it to be clean.
07-08-2012, 02:07 PM
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What do you mean clean the throttle body? wouldn't I need to remove it to do that?
07-08-2012, 04:12 PM
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a car that can't do the throttle reset.
Intake.. I will try to find it in my service records, but I believe there was a crack at the inlet or something to that affect.
11-13-2012, 12:47 PM
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2005 c55 amg, 99 E36 m3, 2007 FX35
I am having almost the exact same symptoms mine just does a scary jerk forward when coming to a stop before stalling out. Did you ever figure out what was causing this?
11-13-2012, 02:58 PM
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Ive had a rough idle for a long time. One of my engine mounts is shot and I have to get around to replacing it, but I'm sure the throttle plate could use a clean...
Mine doesn't stall out all the way, but it can be jerky when coming to a stop. Almost feels like a terribly warped rotor (which I know is not the case)
Mine doesn't stall out all the way, but it can be jerky when coming to a stop. Almost feels like a terribly warped rotor (which I know is not the case)
