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The 2 most common snesors that give incorrect readings... - Printable Version

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The 2 most common snesors that give incorrect readings... - Rawze - 02-18-2016

Here are the 2 sensors for the CM871, CM2250, and CM2350 engines that seem to have the biggest impact on fuel mileage. Sad part is, they will hardly ever throw a fault code.

[attachment=1113]


RE: The 2 most common snesord that give incorrect readings... - in2trux - 02-18-2016

Average cost less than 1 hour at Cummins ($153)


RE: The 2 most common snesors that give incorrect readings... - Rig Wrench - 02-18-2016

I've had an issue with my 871, on its third imap sensor in 90k miles. It will be fine, then have no manifold pressure, then jump back to normal. It will do this back and forth until I replace the sensor. Mine is the only one in the fleet givin an issue. Anyone ever have similar problem? Maybe a fluke?
Thanks


RE: The 2 most common snesors that give incorrect readings... - Pro Star Cummins - 02-19-2016

Hello, Could it be a wiring issue, short or bad ground ?

I could be wrong , parts made in Mexico and such.


RE: The 2 most common snesors that give incorrect readings... - 1096 - 02-19-2016

I had 37 counts on my Exhaust Pressure. I pulled the tubing running to it first and found it completely plugged. I replaced the tubing and have not had a problem since. I have not changed the Sensor yet.


RE: The 2 most common snesors that give incorrect readings... - Rawze - 02-19-2016

(02-18-2016 )Rig Wrench Wrote:  I've had an issue with my 871, on its third imap sensor in 90k miles. It will be fine, then have no manifold pressure, then jump back to normal. It will do this back and forth until I replace the sensor. Mine is the only one in the fleet givin an issue. Anyone ever have similar problem? Maybe a fluke?
Thanks

I would examine one closely and see if it is getting contaminated with something.


[attachment=1114]
The pressure part of the IMAP sensor is up inside the head of the unit (as shown in the pic). This means it will clog with soot long before the "cage-looking" part of it clogs up. The pressure sensor itself is also a capacitive sensor, and solvents will partially short it out, making it read incorrectly. I.E.> Cleaning one with solvents will usually make it read wrong. There is no way to properly clean it - It is better to simply replace it when it starts getting clogged up.


Tags:
imap sensor, imap pressure part, intake pressure sensor, imap capacitive sensor



RE: The 2 most common snesors that give incorrect readings... - Kenworth2012 - 02-19-2016

(02-18-2016 )in2trux Wrote:  Average cost less than 1 hour at Cummins ($153)

For both or each??


RE: The 2 most common snesors that give incorrect readings... - Rawze - 02-19-2016

(02-19-2016 )Kenworth2012 Wrote:  For both or each??

that sounds like the price for both. The IMAP is usually only about $50 bucks give or take.


RE: The 2 most common snesors that give incorrect readings... - in2trux - 02-19-2016

Price was for both.