a friend sent me this email and I thought I'd post it here, since we're getting nowhere fast-----
Got a problem for you. 98 jeep Cherokee quit running when going down the
road. Female friend of my son. Won't crank. Tested with timing light and
could just see it about 15 degrees off. Figured timing gear bad. 214000
miles. Distributor did not point to #1 cylinder. 4.0 in line 6 cylinder.
Jason pulled it apart and said chain was loose but didn't think it was
enough to jump time. Gear marks were lined up (he put screwdriver in
cylinder to see when it was at the top) but distributor did not point to
#1. He replaced gear and chain, water pump, plugs, wires, rotor button,
and crank position sensor. Distributor still did not point to #1
cylinder. He pulled distributor to check gear, looked ok. He put it back
so it points to #1 cylinder. Checked with timing light shows about 2
degrees off. Put noid light on fuel injector.....is firing. Checked fuel
pressure, about 40#. Checked spark plugs, are firing.
What are your thoughts?

he says that he has sprayed starter fluid into the throttle body and into a spark plug hole
and not even a burp when he tries to start it --

 

It would be unusual for the timing to become an issue while driving down the road and it suddenly quits running.

1) Quits like stuttering/choking/coughing....or quit running like somebody pulled the key out?

I think going down the timing track isn't going to help (timing IIRC was not something that needed adjusting in those years).

2)fuel pressure needs to be 45 +/- 5 PSI

3) I think CPS.

So, no crank-no start, like in "nothing happens when turning the key"? That could be other things as well (like NSS, but that would not explain the dying while driving).

In other words: need more info please

 

I agree sounds like the CPS, they did replace with an OEM one correct? If not its not uncommon to get bad ones out of the box as in even more than one, documented by some members here. It and the TPS are the 2 as I remember that should be OEM replacements.

 

Yep.

 

With #1 at TDC compression stroke, the distributor rotor won't be pointing directly at #1 in the distributor. It will be slightly past #1 (see pic).

Fuel pressure spec is 49.2 psi +/- 5 psi. 40 psi is too low. Suspect a failing fuel pump.]

With the #1 cylinder at TDC compression and the index mark on the vibration damper aligned with the "O" mark on the timing chain cover timing marks the rotor should look like this, and a 3/16" punch should drop in the alignment holes.



Edit: Remember, the damper/index marks will align at "O" twice. Once when #1 is at TDC Compression and again when #6 is at TDC Compression. If #6 is at TDC Compression #1 is at TDC Exhaust.



At idle, the timing will be anywhere from 11* to 18* advance. I don't know what you were looking for when you used a timing light. Timing is controlled by the PCM.

 

engine just quit while driving, motor spins, but not even a burp trying to fire,
even when starter fluid is sprayed into throttle body while cranking.

 

You say that there is spark? But is it a strong blue spark? Any other color will cause problem with starting and will also cause it to die of you can get it to run. I would check you CPS and the ignition coil, The coil may be weak. Also as Mr. CCKen said your fuel pressure is also to low. It should be 49psi +/- 5 psi.

 

Would be helpful to find out where we stand with this, as in checking for spark and fuel. Fuel pressure is too low regarding specs, but still not have cleared spark scenario either....

And correct on the fuel pressures, 45 should be 49, typo.

 

I don't think it has spark. Very rarely I've I seen 4.0s with timing chain issues, but if it was loose, then so be it...

I'd also check that the asd relay is tripping properly. Did she hit a big bump? The coil grounding properly? True pressure may be lower then spec but I would be suprised that it wouldn't try to fire because of lacking 5#.

 

I haven't seen the vehicle at all. My friend first sent me an email then he called me.
I asked about the color of the spark and he said it was blue. I think he mentioned they also changed the coil, idk.
I have sent him a link to this page, hoping he will join in.