TIMING THE ENGINE

[nape]

I think Ihave a broken timing chain. Will I find any ugly things in there when I pull it down? Is there any secret to timing the engine? Do you just align the timing marks? I searched and found an article that said something about finding tdc, is that necessary? I am going to scavenge another engine for parts and try to put this thing together by Sat. What do you think? I think one of the bolts for the inj. pump gear was dropped into the cover. One was missing and we figured it was lost. I guess not. It cranked ran about 2 seconds and made an ugly sound. Spins free and doesn't try to move the vacum pump so I figued either a broken chain/gear or camshaft. I am hoping for a chain. Thanks for any info. Wayne


86 CUCV, 90 Sub 1500 W/ats turbo, 87 sub/6.2, 87 C30 6.2/broken, 83 Sub 6.2 trans/broken, 82 Sub 6.2/broken, 3 6.5 dealer pull outs, 1 wife, 4 sons, 1 daughter inlaw, 1 grandson

[wthif]

If you have a broken timing chain, the valve stems are most likely bent or the push rods are. If the cam isn't turning same problem. If the vacuum pump isn't turning I would be wondering if the oil pump isn't also. You'll need to take a look before you can find out if you can finish by Saturday. I hope there is something else going on. I let someone else chime in about timing because if you truly have a broken timing chain and you turned the engine over that way you have bigger problems. Sense the engine ran for two seconds probably not a broken timing chain because it wouldn't run with out the timing chain, because injection pump wouldn't turn over. The vacuum pump not turning worries me because it drives the oil pump and no oil pressure could make some bad/ugly sounds while running.

Anyone feel free to correct me if I'm wrong and I'll let the people with more experience with timing chime in on that.

[ 08-21-2004, 12:30 PM: Message edited by: wthif ]

[Peter J. Bierman]

If you are able to trn the engine by hand, it is not likely the chain is broken couse the valves will stop the pistons from moving up.
If you take out the oilfiller pipe you can see if the pump sprocket is moving, if this is the case the chain is still on.
To be check the chain for sure you have to disasemble the front off the engine so you can see the chain and other timing components.

Peter

[nape]

Well no broken chain but worse a stripped cam key. I pulled the timing cover and found a stray bolt in the mix. I replaced the key timed the engine and found a locked up fuel pump. I don't know how that happened but replaced it and cranked the engine. Runs, misses and makes ugly sounds. I wonder if there is a chance that it only bent the pushrods? Has anyone ever experienced anything like this? I think I will try to replace the push rods and see if that works. Thanks for any thoughts. Nape

[JeepSJ]

My experience has been that the valve bends before the pushrod when a piston contacts a valve. The valve bends and gets stuck and that is what causes the pushrods to bend.

[diesel65]

Visually inspect the rocker arm shafts for cracks around the bolt hole where it bolts to the head.

[nape]

I must wait a few days to tackle the valves or pushrods. I don't want to have to pull the heads but it is looking like that is the next step. I will respond when I have some more info. I sure do appreciate the DieselPage. I wish I had known about it years ago when I first began to run these things. Thanks again. Nape