4.0l ?

JAWS · Oct 8, 2012

I have a 98 cherokee in the shop!! I got it running. But it runs ruff.. Pulled codes. N got PO320 Crankshaft engine speed RPM sensor circuit malfuntion..

My question is ive seen CPS go out N a car die or not start will they still run if one is bad or going bad!!!

WA-Wheeler · Oct 8, 2012

In my experience they usually just go out and you get no start, but 98 is newer, maybe these ones throw a code when they are dead....

Spanaway Mudder · Oct 8, 2012

Thats a spendy "test" if you end up buying a new CPS...

TreeClimber · Oct 8, 2012

JAWS said:
I have a 98 cherokee in the shop!! I got it running. But it runs ruff.. Pulled codes. N got PO320 Crankshaft engine speed RPM sensor circuit malfuntion..

My question is ive seen CPS go out N a car die or not start will they still run if one is bad or going bad!!!

On buddies 98 TJ, the crank sensor was relocated to the front pulley when he did a trans swap. It would eat sensors due to the heat / exposure, and he would have to replace periodically. Every time, the vehicle would quit running.

Zoediak · Oct 8, 2012

I would check to make sure there is not a damaged wire floating around in that circuit, and make sure the sensor isn't loose or dirty connection..

start cheap... :awesomework:

JAWS · Oct 8, 2012

Zoediak said:
I would check to make sure there is not a damaged wire floating around in that circuit, and make sure the sensor isn't loose or dirty connection..

start cheap... :awesomework:

Yeah with all sensor diag thats the first thing i did was check the wires for damage and the wire connection for bent pins dirt or oil!!!

TrikeKid · Oct 8, 2012

JAWS said:
Yeah with all sensor diag thats the first thing i did was check the wires for damage and the wire connection for bent pins dirt or oil!!!

Sensor bolted down tight? If you have a known good one around it'd be easy to swap and check but a bad crank sensor is usually gonna mean no run at all.

popcancherokee · Oct 9, 2012

Its a hall effect something else setting off that sensor code.my 91 set off cps code and it was the distributor.run some seafoam and go from there.good luck you will figure it out.

Avanteone · Oct 9, 2012

Most likely bad CPS. They die like flies on these things.

nwwheeler08 · Oct 9, 2012

CPS sensors are a pretty common problem with the 4.0l but its usually a no start/no spark problem. Id start looking at wiring. is it only running rough when cold or hot? have heard of that code being thrown from a distributor, coil and cam sensor.