Birty Dastards Jeep Club

Tech Forum => Workshop => Topic started by: bluejeep on December 12, 2010, 05:55:01 PM

Title: 98 cherokee xj limited 4.0 petrol problem with engine cutting out
Post by: bluejeep on December 12, 2010, 05:55:01 PM

hi to all
i've just joined up so i am feeling my way here, so apologies if i inadvertently make a boob.

well i am hoping some of you more knowledgeable guys can come up with some answers or possible areas to investigate.

i have a 98 cherokee limited 4.0 straight six petrol. the problem is that it has started cutting out after a few minutes of running. this happens both when it is sitting stationary ticking over, or when running on the road. the time/distance from starting to the cutting out is not consistent. but, the thing that i find odd, is that after cutting out, it will re-start immediately and then run faultlessly.

i did have a problem with a faulty safety neutral inhibitor switch which i have replaced and that seems to be working fine.
so any help, info, advice would be appreciated, thanks

Title: Re: 98 cherokee xj limited 4.0 petrol problem with engine cutting out
Post by: isle of man on December 12, 2010, 06:26:25 PM

From your description it's highly likely the crank position sensor is foooooked.


And hello....

Title: Re: 98 cherokee xj limited 4.0 petrol problem with engine cutting out
Post by: Mike Pavelin on December 12, 2010, 06:47:58 PM

 :imwitstupid:

Title: Re: 98 cherokee xj limited 4.0 petrol problem with engine cutting out
Post by: eastryjeep on December 14, 2010, 12:52:51 PM

Yup, TPS now reclasified U/S!

Seem to remember it being an easy DIY job, just need fingers like ET!

Once purchased a knock off copy from a motor-factor but it didn't last, would suggest sticking to the real Mopar bit.

Title: Re: 98 cherokee xj limited 4.0 petrol problem with engine cutting out
Post by: bluejeep on December 14, 2010, 10:48:33 PM

hi isle of man
thanks for your prompt reply, could you elaborate a little further as to how i could test your theory, and is this something i can repair/replace myself. i have a bit of mechanical ability, just don't know jeeps. also perhaps to expand on my problem, once the engine cuts out and is then re-started it seems to run forever. until, it is switched off. and then the same thing occurs the next time it is started up. would this be consistent with your diagnosis of the u/s crank sensor. once again many thanks for your help.

Title: Re: 98 cherokee xj limited 4.0 petrol problem with engine cutting out
Post by: bluejeep on December 14, 2010, 10:52:40 PM

hi eastryjeep

could you translate "TPS" please, and if possible give me some idea of why this would cause the problem i am experiencing. i don't suppose i could just by-pass this sensor to overcome the prob???

thanks for your assistance

Title: Re: 98 cherokee xj limited 4.0 petrol problem with engine cutting out
Post by: JamesH on December 15, 2010, 01:00:48 PM

Crank Position Sensor (CPS) on bellhousing and possible to change DIY

TPS is Throttle Position Sensor and easier DIY change but it seems CPS is your problem so this wouldn't help

Title: Re: 98 cherokee xj limited 4.0 petrol problem with engine cutting out
Post by: Dave69 on December 15, 2010, 08:24:21 PM

have a look here

http://go.jeep-xj.info/HowtoCPSchange.htm (http://go.jeep-xj.info/HowtoCPSchange.htm)

Title: Re: 98 cherokee xj limited 4.0 petrol problem with engine cutting out
Post by: eastryjeep on December 16, 2010, 01:17:55 PM

Sorry BlueJeep
TPS was a typo, as opposed to a rush of blood to the head, should have read CPS!
It is most definately the Crank Position Sensor, the fault characteristics you describe match it to a "T".
The little sod is mounted on the gearbox bellhousing at about the 2 O'clock position when viewed from the front of the car looking back (i.e. on the passenger side of a RHD car).

Title: Re: 98 cherokee xj limited 4.0 petrol problem with engine cutting out
Post by: isle of man on December 16, 2010, 03:55:28 PM

Quote from: Dave69 on December 15, 2010, 08:24:21 PM

have a look here

http://go.jeep-xj.info/HowtoCPSchange.htm (http://go.jeep-xj.info/HowtoCPSchange.htm)

Brilliant link that...

Title: Re: 98 cherokee xj limited 4.0 petrol problem with engine cutting out
Post by: Dave69 on December 16, 2010, 08:20:11 PM

lots of other nice ideas on the site as well

Title: Re: 98 cherokee xj limited 4.0 petrol problem with engine cutting out
Post by: big g on December 16, 2010, 08:45:26 PM

The NSS section is good,think it's been linked on here before.