E-Class (W124) 1984-1995: E 260, E 300, E 320, E 420, E 500 (Includes CE, T, TD models)

1993 300E 2.8 CPS sensor??

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Old Sep 18, 2016 | 12:39 PM
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GuilhermeRocha's Avatar
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1990 200D, 1992 500SL, 1993 300E 2.8, 1997 E220D, 2012 E250CDI
1993 300E 2.8 CPS sensor??

Hey guys need a little help. In the last few days my 300E 2.8 got a few idling/misfiring problem. In cold works fine, in hot, misfires and idles very poorly. I leaned that the CrankShaft Position Sensor might be bad so I readed the resistance value and it's about 940 ohm's, very in the 800-1200 range. The other plug that goes to the EZL (I THINK) reads about 4550 ohm's, alot more that the plug from the CPS sensor.
The weird part is that running the car this only happens a few times during driving, but now it getting worse. I can be driving 1 whole minute fine, and then I get 20 seconds of not appropriate engine behaviour.
I recorded a little video and I got a description in it to you guys tell me if this could be possible

PS - The car "computer" also tells me that it got Error 24 - CKP sensor or magnet for position sensor not recognised.

PSS - Alredy changed spark plugs, wires, coils and MAF in the recent 4 months.

Here's the video:

https://www.youtube.com/watch?v=952H...ature=youtu.be

And description, on the Youtube there is also:

0:17 - Shift to Reverse
0:20 - 0:35 Poor idlind
0:35 - Good clean rev and back to Reverse
0:35 - 0:47 - Good idling
0:47 - 0:54 - Poor idling
0:55 - Not a good rev, the car also shakes while pressing the gas
0:56 - Again in reverse, with poor idling



Thanks
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Old Sep 18, 2016 | 01:14 PM
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'90 300CE M103 Manual '93 Alfa 164 QV24 '05 Jaguar X350
I recall a mechanic telling me a story of a 300CE24 with similar symptoms as yours. It turned out that there was a heat conductor layer under the EZL which had turned bad or was not replenished/renewed when the previous owner replaced the EZL, so when the car heated up the temperature difference causes the engine to misfire. Suggest you measure the temperature difference between the EZL and its surrounding metal surface area at operational temperature. In normal circumstances, the temperature of the two should largely be the same.
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Old Sep 18, 2016 | 03:18 PM
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GuilhermeRocha's Avatar
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1990 200D, 1992 500SL, 1993 300E 2.8, 1997 E220D, 2012 E250CDI
Originally Posted by QVHK
I recall a mechanic telling me a story of a 300CE24 with similar symptoms as yours. It turned out that there was a heat conductor layer under the EZL which had turned bad or was not replenished/renewed when the previous owner replaced the EZL, so when the car heated up the temperature difference causes the engine to misfire. Suggest you measure the temperature difference between the EZL and its surrounding metal surface area at operational temperature. In normal circumstances, the temperature of the two should largely be the same.
I am sorry but there was a confusion, my car has no EZL module, it's a HFM-SFI system. The CPS is wired directly to the main HFM ECM, whihc manages injection and ignition.

So EZL is not possible, since the car has not it
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Old Sep 18, 2016 | 09:41 PM
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'90 300CE M103 Manual '93 Alfa 164 QV24 '05 Jaguar X350
Then if the computer says CPS, would replacing it cure the problem? Here is a technical guide on the CPS. An after-market CPS costs about $20.
http://www.pelicanparts.com/techarti...ing_Sensor.htm

If not the CPS, it would have to be engine management related issues caused by the engine receiving no or inaccurate data: the 'computer', engine harness, O2 sensor or catalyst converter, or loose electrical contacts somewhere. Also, it could possibly be caused by some of the items that you recently replaced, i.e. the spark plugs, wires (what wires?), coil and MAF. Why did you replace them in the first place? If the shaky rev often happens when gear is in reverse, it could be mechanical or wire contact near the gearbox. Just guessing. Others please chime in.
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