Goo-fouled CPS

[Edge]

Afte having a the engine die on more than one occaision,I started going thru one of my cherokees for some overdue troubleshooting.The fuel pump scoped bad,I replaced it,ballast resisitor was cracked,replaced that,ign module had a hole in it,replaced that,all relays and electrical tested good.

THEN,after 90 miles,under power,it dies.Next thing I checked wa the CPS,which was completely fouled with oil(valve cover leak)dirt,etc......would that cause intermittent cps syptoms?Thre was a LOT of crap on it.

I replaced it anyway,but am curious if just cleaning it would have been ok.

Havent had time to drive it since,so dont know if thet CPS was the cause of the stall out anyway.

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[SteelHeadz]

CPS and CKP's are generally sealed sensors. Oil and grease shouldn't affect them to cause failure. They do generate a magnetic field and may in time accumulate metallic debris. With the combination of oil or grease with the metallic flakes CAN cause a false signal between the sensor and the tone ring but very rarely seen happen.. I would think that the ECU would have generated a DTC for a no signal at the PCM from the CPS.

 

[Edge]

The only code this cherokee has ever had was emmissions mainteneance........my 88 is a code incubator,but I digress....

The sensor itself is sealed but the port it goes in is more of a slot than a hole....on the old sensor ,rather than the pin protruding from a flush surface,it looked more like a really bad cue-tip.As in pool cue.Not the ear kind.

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[SteelHeadz]

Have you tried to run the engine yet to see if it worked?

 

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Yeah,it runs,but I cant drive it yet(foot surgery)so it'll be a few days til I can put it to the test.Running is good,but the problem has always been intermittent(the die under power problem)hopefully this will solve it for good.
Just dont want to pitch the old cps if it might still be good now that I de-gunked it.Once I can amble out tto the shop I'm gonna test the old one under a heat gun to see if that affects it.......

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[Edge]

Put on a couple hundred miles now,no failures........just in time for meltoff...snowboarding is over for the year.Flyrods and hiking gear are already on board...cant wait.

Thanks much for the help guys.

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PS,I checked out the old cps and could not get it to fail......musta been the gunk.I'll replace my valvecover gasket and my intake mani gasket tis week.