benjiboy64

I've got a 94 XJ 2.5l 5spd 4dr 2wd. I have the infamous rattle at idle. Thought it could be lifters but hadn't investigated yet. Also it has hesitation/ backfire glitch around 2500rpm. Cold or hot it's there. Its less noticable when I apply steady , light pressure to the gas pedal. At highway speeds, 75+, it has a noticeable hiccup that occurs about every 20 seconds. It feels like if you were to rapidly shut the key off and back on....every 20 seconds. I've learned to tap the accelerator slightly during the glitch so it's barely noticeable. When driving in town and it glitches if I give it gas it sputters and backfires so I've learned when it starts I let off the gas and it helps. It has 266000 miles on it and I only paid 600 for it. I have changed the plugs, wires, dist cap, rotor, maf, tps, iac valve, intake manifold pressure sensor, fuel filter, and random other stuff. I read somewhere about the rattle at idle could be the timing chain rattle.

I decided to put 92 octane in it based on another members post stating it helps his random stumbling and hesitation. I parked it that night and when I got in it the next day it was "glitchier" than before but I made the 20min drive to work.

When leaving for lunch I got about 3 miles then it started bogging down, backfiring, then die. Get it restarted, ran about 2 miles then died.

I am now thinking timing chain. So I ordered one.....decided to go ahead and change water pump, thermostat, housing, and temp switches, and radiator. Tore it down today and to my disappointment the timing chain was fine.at TDC all the marks were in line. Pull off the distributor is 180 degrees out. WTH? How does this happen? This is my first timing chain replacement. Wasn't hard to tear down. I noticed when I took the sprocket off the cam the cam tried to slide out with it. It moved about half an inch but I got the sprocket off and gently tapped it back in. Oh and yes, the licking pin behind the sprocket is intact. It started raining here so I put everything up and called it a day. Tomorrow going to reassemble. I've read I could just leave the distributor the way it is and just switch the wires. Others say to pull and reposition the distributor. Not sure which would be best. So #1: what could cause a 180 degree rotor flip..... #2 is the cam supposed to be bearing locked to the head or should it be able to slide forward like that. Seeing as the distributor is driven by the cam is it possible it slid forward enough to skip teeth on the distributor gear? I'm still researching but anyone of my fellow XJ wrench turner's encounter this? Thank you in advance!

lawsoncl

Have you changed the crankshaft position sensor yet? Sputtering and dying sounds more like fuel though.

freegdr

Timing chain marks and Top Dead Center are two different thing. Put timing chain and gears on ....Do not mess with distributor or wires. At idle gently depress cluch pedal does rattle go away ?

Dave51

Not having the crank at TDC on it's compression stroke.

benjiboy64

I know top dead center and timing chain marks are different but when I have the engine at top dead center and I took off the timing chain cover the timing marks for spot on where they're supposed to be in line but the distributor was a hundred eighty degrees out I'm wondering how this can happen.

97grand4.0

Fuel pump. Check pressure. Parts Cannon at the ready, can he stop it??? Fire One!! Oh no he already ordered a timing chain. Ready, Aim......

Dave51

A PO had the distributor out, didn't do above and changed the wires to make it work. Re-index the distributor to get you back to normal.

They are supposed to look like this (Cruiser image):



http://www.angelfire.com/my/fan/dist_index.html

97grand4.0

It's mechanically fine, and you can leave it until you finish the chain, it will run like that but you can turn it around some other time.
Also when you do the chain, a few things to watch out for.
First the bolt, has a spring AND a pin in the end of it. This keeps the cam from walking back and forth in the block. Replace the spring and don't leave out the pin. Use a torque wrench on the job if at all possible. Examine the timing cover to see if it's bent or worn bad.where the cam is. I used a Cloye's chain from NAPA. It installed tight, tight. No deflection. The fsm makes a big deal of counting the links, but, unless you go with mopar chain you may not have the same number. But as long as you use the Cloyes chain and gears set you should be ok imo.
Just don’t change the chain without the gears, or things may not mesh up right.
Also, there is an indexing pin in the shaft that locates the big gear. Consider changing that. The fsm says to change it. I didn't on mine but ....it's your call.