plea for help: Timing chain marks, piston position, TDC keep coming up wrong! (Solved!)

This is the 4th 'time around' and I keep coming up with inexplicable results, I need a fresh mind to point out whatever obvious thing I keep tripping over.
the situation: head off truck, replacement in garage gathering dust. Re-sealed oil pan, etc. Purchased new 'OEM" 'timing kit' from Mahle, incl. chain, guides, crank timing sprocket, cam sprocket, gsskets. Replaced all, reassembled (with careful attention to correct timing alignment etc), hung cam sprocket/chain from hood. Spun crank 'round couple times to check operation and satisfy my slightly ocd tendencies that all was as it should be, timing marks all re-aligned where they should be....NOT. Huh? o-kay...maybe chain slipped, skipped teeth on sprocket somehow.yeah that must be what happened. Disassemble, re-check, re-align, reassemble. Same results. WTF? Man, must be ME slipping. OK, payin attention for sure now.... Rinse, repeat. AGAIN. TWICE.
What am I missing here?
After two revolutions of crankshaft I should be back on TDC (compression stroke, yes, not so you could tell w/head off, but....) and 'bright' or 'marked' links on chain should be where they started, i.e. @ top of sprocket in line w/mark on sprocket. Right? Right? rrriiiiiight?
'k, can't be right 'cause that's not what's happening . Would somebody please explain where I went off-track? I'm so frustrated at this point .... feelin stuck on stupid,no objectivity left, would be grateful for a fresh viewpoint.
Thanks for your time, y'all.

 

is one or both sides off on the marks? only thing right off hand I can think of is wrong crank sprocket or wrong cam sprocket. which allows one or both timing marks to be off. are you sure you are counting the crank travel? Others correct me if I am wrong, But It should go two full travels to be at TDC on the compression stroke,

 

The chain does not have the exact number of links to come out with the links in the same spot. I don't know the timing mark alignment procedure for this motor, but if it involves using the marked links, so many links apart, it's not going to come out the same after you rotate it.

Now, a small block chevy, where you line up the marks on the sprockets relative to each other, will always line up after 2 revolutions.

 

sorry, I should have put this info on my 'plea'- I have a 96 (1st gen) 2.4l 2wd auto; '2rz-fe' engine. There is only 'one side'.
I compared the parts (old to new) very carefully when I received them. And twice again, since then. Got pics, even (for my own reference, I must have seen this coming or somethin). Sprockets and chains are near identical, except for wear. I say 'near' because the new chain feels somewhat lighter in weight, but that is a subjective observation. I did say I've no objectivity left, I think..
can you elucidate what you mean about counting the 'crank travel'?

oh sh-- are you serious? well that makes too much sense, you must be! I have NO idea where I got the idea they should come out in the same place......unless some distant memory of working on my GTO, back in the day..... Thank you, I think :E Damn.....

Anyone have further thoughts on this?

 

Next question: now what?

I cannot bear the thought of tearing it all down again to re-align the crank timing sprocket to the chain.....(I follow the FSM pretty closely, use Haynes and Chilton's for backup/clarification/different perspective....but I think my most valuable resource is right here : the TacomaWorld habitues
I've completely mind f-ed myself so I'll ask, again: Now what?

 

While I didn't replace the entire timing chain and assemblies, I did recently remove both the intake & exhaust camshafts from the cylinder head. Before doing so I did make sure the #1 cylinder was at TDC via the crank pulley mark and the alignment marks on the backside of the cam gears. I also zip tied the chain to the cam sprocket and supported the sprocket to ensure the chain wouldn't fall from the lower crank sprocket. I reassembled everything in the same orientation/alignment; after doing so I rotated the crank by hand many times, making sure that all marks lined up exactly after every two crank revolutions. I never once paid attention to any markings on the chain links themselves. The markings on the chain links are there for the initial installation of the timing chain to ensure the proper number of links are spaced between each sprocket/teeth. I agree with Muddinfun that the chain link markings will not re-align as installed with only two rotations of the crank - who knows how many times you'd have to spin the crank to have them re-align . Photos below are with the #1 cylinder at TDC prior to disassembly. Also this is a 3rz engine - camshaft timing procedure should be the same for the 2rz. Hope this helps!

 

Yeah, what the others have said makes a bit of sense -- forget about the marks on the chain itself once you start turning it with everything hooked up. If the pulleys/sprockets are attached correctly (hard to get them wrong) and the marks are where they are supposed to be when at TDC, you should be good . . .

EDIT: FWIW, I haven't done this for a while, and not on that engine, but I have never relied on the chain or belt to tell me when things are aligned, only the marks.

 

Just a thought. The crank ratio of rotation is--- 1 revoluion of the crankshaft is a 1/4 rotation of the camshaft.
I assume your at TDC of number 1 cyl. Rotate the crankshaft 4 complete revolutions that way the camshaft will rotate 1 compete revolution and the piston will be TDC compression then check your timing marks.
The timing marks during assembly at the factory had to line up to a given mark/point.
Just my 2 cents . Good luck and please post the results
TOMB

 

kind of what I was thinking but I thought its basically two full revolutions of the crank would get you to TDC?

 

Yeah, sitting here drawing circles on my desk trying to wrap my head around it. I think it is 2 as well -- intake/compression = one turn, ignition/exhaust = two turns, back to the beginning. That said, I still don't think that means that the links on the chain will be back in the original position. They will eventually, and when they are, everything should be lined up again.

Just checked, the 2.4 crank sprocket has 18 teeth, cam has 36, so yeah, 2 turns.

 

I'll echo what wilcam47 and TenBeers mentioned above; the crank to camshaft ratio is 2:1. One revolution of the Crank = 1/2 revolution of the camshaft(s).

https://www.google.com/search?q=cra...7j69i60j0l3.3175j1j7&sourceid=chrome&ie=UTF-8

 

I stand corrected on crank cam ratio. I based my info from an older explanation
TOMB

 

No worries, at least it made me do some thinking. At first it seemed to make sense!

@lvs2rock If all the pulleys and gears are installed properly (hard to do it wrong), the marks are lined up properly, and you get the chain links matched up on initial install, turn the crank 2 full turns and all the marks are lined up again, you should be golden. But this thread is getting old, you either figured it out or punted, but interested to know if you got it running.

 

hey all, again MANY THANKS for all the good intel and info, you guys ROCK.
Weather and work schedules haven't been cooperative. But. _ Finally_ got head on TODAY, headbolts torqued but that's all so far.......
I will be back to make some individual thank yous and update progress and (hopefully successful!) results.

 

I’m having this same exact problem for the same truck 2.4 97 Tacoma but every time I fire it up and it runs the timing is off a like 10-15 degrees I’m not use to the 2rz motors it’s driving me nuts torn it apart like 6 times now to double check what I’m doing wrong

 

First, what do you mean that the "timing is off like 10-15 degrees". Are you pulling the valve cover, lining the crank up to TDC with the marks on the front cover and then looking at the cam mark, are you checking ignition timing w/ a timing light? How are you determining that what timing (cam timing and ignition timing are 2 different things, and independent of each other, sort of) is off like 10-15 degrees?

Typical process after installing all the timing shit is to spin the engine over 2 crankshaft revolutions and re-check timing. The marks on the cam and crank PULLEYS should be in the appropriate spot, but the shiney links or odd links or however they've marked the chain to aid in initial assembly will be somewhere else....that's fine, ignore them....they don't matter after you've turned the engine over....they're just there to help get stuff on right.