Calgary Jeep Association

4x4 Related Groups => Tech Talk => Topic started by: ornamental on August 03, 2014, 12:05:41 AM

Title: 4.0 litre chokes and died
Post by: ornamental on August 03, 2014, 12:05:41 AM: Need help getting 98 XJ running .
2 weeks ago engine hesitant, rough idle so I change plugs and it runs fine. Friday it's running rough again. I cycle ignition but can't get a code to appear even though check engine light is on.

Auto value Guy plugs in the scanner and says misfire on cylinder 3 and 5. And try new wires....
Jeep dies on the way home so I drag it back with the other jeep. This morning I swap new plug wires and check plugs.

Starter spins but no start. Smells a little like gas at engine. Sounds like a burp at the engine, what's wrong with this mess, where should I be checking?
Title: Re: 4.0 litre chokes and died
Post by: Immortal on August 03, 2014, 12:41:29 AM: Had a very similar issue with my old 99.... crank positioning sensor was the culprit.
Title: Re: 4.0 litre chokes and died
Post by: ornamental on August 03, 2014, 01:12:48 PM: Did your jeep throw a code? How did you figure that?
Title: Re: 4.0 litre chokes and died
Post by: EEP on August 03, 2014, 01:41:13 PM: Check the jeep cherokee forum, lots of good info on there regarding CPS.
Title: Re: 4.0 litre chokes and died
Post by: Immortal on August 03, 2014, 02:21:07 PM: No code. I was pulling my hair out. Had it towed to broken axle, they fixed me up... I even went so far as to replace the fuel pump without dropping the tank.
Title: Re: 4.0 litre chokes and died
Post by: cLAY on August 03, 2014, 10:20:34 PM: Had the same issue on my 5.9 ZJ. Intermittent miss that over time developed into a stall and eventually wouldn't run. Found one of the wires for the CPS was chaffed thru and grounding out. Never got a code for CPS, just codes for various miss fires.

I've had numerous CPSs fail on me over the years and have never gotten a code for it.
Title: Re: 4.0 litre chokes and died
Post by: ornamental on August 04, 2014, 12:12:37 PM: Thanks guys, have sesor, just need to swap it in now
Title: Re:
Post by: BUKI on August 04, 2014, 10:29:38 PM: Post up an update afterwards I'm interested how it all worked out
Title: Re: 4.0 litre chokes and died
Post by: ornamental on August 05, 2014, 10:39:55 PM: I finally have the sensor installed. What a PITA.
I disconnected the back of the front drive shaft and squeezed hands and tools in there.
Once installed it almost fired up but no luck. I don't have it torqued to spec, is it that critical for it to start? I'll try again tomorrow after I charge the battery up.
Title: Re: 4.0 litre chokes and died
Post by: JENSSEN on August 06, 2014, 07:14:42 AM: You pulled a drive shaft to do a CPS?
Title: Re: 4.0 litre chokes and died
Post by: ornamental on August 06, 2014, 09:01:53 PM: Crank shaft position sensor is below and cam shaft position sensor is above.
Anybody want to come over and rescue this POS.
Title: Re: 4.0 litre chokes and died
Post by: cLAY on August 06, 2014, 11:04:49 PM: Crankshaft sensor is on the bell housing around 1 o'colck as viewed from front.
Cam sensor is in the bottom of the distributor.

Have you checked fuel pressure? Not sure on the newer models but on the older ones there is a what looks like a large tire air valve on the fuel rail. If you remove the cap and push on the shrader valve inside does fuel spray everywhere or just trickle out?

How much fuel is in the tank?

Also consider the coil. Or is it coil on plug?
Title: Re: 4.0 litre chokes and died
Post by: Immortal on August 07, 2014, 07:53:20 PM: Coil packs started in 2000, so it'll have plugs. And it should have a fuel line pressure access... my 97 does, and the 99 did.