1993, 4.0, 197K miles.

I had multiple problems that needed to be fixed, so I got out my trusty Haynes book and dived into the deep end, head first. Here is a list of things I replaced:

Exhaust manifold -old one cracked
water pump - "autozone special" leaked
timing chain/sprockets- was clacking away
chain guide - why not? was in there anyways
motor mount - cracked
lifters - tapping
oil pump - loud whirling/whining noise with my trusty hose to ear trick

I cleaned the heads off and decarbonized the valves, (poor man's head job). I scrapped carbon off top of pistons. I took out and inspected camshaft/distributor shaft. To my untrained eyes, it looked fine w/no chips or cracks?.. Lined up timing marks per Haynes, and put it all back together. Exhaust manifold torqued to specs, timing aligned to TDC, oil pump primed and installed. Distributor is keyed to 0 and 180, so at TDC it was at No. 1 cylinder. Piece of cake! Anyways after all was said and done, I fired it up. It cranks and idles fine. I drove down the road a little and all heck broke loose. Loud metalic tap, and something like a heavy metal object being tossed about. I think it may have been a lifter so I checked rods/valves. I took off the rocker arms again a made sure all of the valves were good. It looked fine and torqued the rocker arms back tight. Cranked it up and all was good, took it out on my driveway and got to my main road. When I gave it some gas, it started to bog down w/metalic tapping sound. It then idles down and dies. After a few minutes, it cranks back up w/good idle. It drives back home on the driveway fine, but not on the highway. I'd like to get some suggestions before I drop some serious cash at some German Jeep dealer or a new engine.

Thanks in advance.

Any sound when reving up without driving it?

Noise from front, back, or middle? Top or bottom?

No sound when I revved it up, went to 3-4K RPM. The noise starts and seems like the exhaust manifold gasket starts to leak (starts to smoke from manifold area) The noise seems to be coming from the left side toward middle (camshaft range). I'll check it again with my magic hose to ear trick and re-verify. Thanks

Ok, no sound when in park. I revved it up for about 20 min and was up to temp. It sounded fine except for injector ticks. Maybe if I take another test drive this weekend, I can narrow the location of the noise. Since it only makes noise when the engine is under load and driving, what do you think it could be? Is the timing good, because it idles fine in park? Thanks

Hopefully, it is not detonation.

Hopefully, it is not detonation.

You know, I've read through this a few times (abid user of the 'new posts' function) so I'm not overly familiar with Jeeps, but do have a I6 AMC, and to me it sure sounds like either the timing is way off, or just simply does not have the advancing mech hooked up.. :2cents:

Sounds like something is installed wrong (perhaps in the timing chain area?) But, did you connect the knock sensor? What is the oil pressure when you hear the noise (could also be collapsed lifter) I'd know exactly what it was if I heard it so right now I'm just "fishing"

I had a chance to poke around and I think I figured it out. Apparently, the distributor is not keyed like I thougt. The "key" was in fact part of the oil pump. Needless to say, I moved the distributor around a couple of teeth, and duplicated the noises. So I must have installed it wrong. Is there an easy way to make sure it is lined up or do you just keep moving the teeth until is runs smoothly?

Thanks

Remove the cap and pull the distributor.
Pull the number one spark plug.
Use a 19mm socket on the harmonic balancer bolt (Clockwise only!!) and bring the number 1 piston up to TDC. You'll hear air escaping the #1 sparkplug hole.
Reinstall the distributor so that the rotor points at 5 o'clock, you may need to align the oil pump shaft notch with a long screwdriver so it properly engages the distributor.
Reinstall #1 plug

Douple check your plug wires and firing order.

I'd agree with Frank. Nothing worse than getting something together and hearing a nasty clatter like that. Double check your distributer. A Haynes manual is only good for starting a bon-fire if you ask me.

Haynes manual on rebuilding an engine.....

Step 1) Disassemble engine.

Step 2) Replace rings and bearings.

Step 3) Put engine back together, torque to specs.

Haynes..... I just love that manual.... it ALWAYS leaves off exactly where I need to know something after reading everything I already knew. I have always wanted to write a real manual including the complete diagnosis and repair of stuff, INCLUDING the stuff about HOW a particular part interacts with other components. (in real world operation). Oh well, probably couldn't sell it anyway!!!

F.s.m.?

A factory service manual is useful, but doesn't cover the auto mechanics knowledge part.

An automotive mechanics textbook could also be useful. Especially for the Jeep XJ, which is largely old school technology.

You also have to keep in mind that the dist. shaft spins when going into place and you need to compinsate for that not only for correct timming but for oil pump key to line up.
All said and done, Your rotor should line up to #1 plug wire on the cap when #1 piston is at tdc on the compression stroke.
Normally, installing the teeth on the dist. one tooth off will guild it into the proper location after the dist. seats all the way in place.

Ok, so I finally had a chance to check on my timing issue. I redid the dist like "Haynes" said to in the electrical section. Funny it didn't reference that section in the engine rebuild section!?!? Anyways, of course it didn't work. It rattled worse than ever. I tried it like FrankZ, and after a couple if tries I ended up snapping my #1 cylinder sparkplug! Anyways, I pressed forward and swapped out the #2 since I heard the 4.0 likes to get the #1 lined up before it cranks. So it cranks and runs like it's missing the #2 sparkplug. I'll have to wait to road test it when my sparkplug comes in the mail. I'll let you know how it goes......