TheEastBeaster

Alright. So its my first rebuild rodeo, meaning lots of mistakes and learning. I rebuilt this motor using multiple sources like haynes, LCE, and Marlin write ups doing alot of double checking. its a 1982 toyota pickup 22r with the duel row timing chain.

So my problem here is that i have no compression when starting. Ive looked at a few things, timing could be off, i may have crunched the valves, or they are just opening to early and letting the air out. I dont believe it has anything to do with the bottom end (HG, piston rings) because my compression rate is literally 0,0,30,0 so i think its timing or valves.

Im looking for some tricks to re position the crankshaft to TDC and check the valves for damage without having to pull the head if all possible. hoping i can just retime again and i was off a tooth on the chain or something. with a compression ratio like this is it possible to damage the valves by just cranking the starter but the engine never ran? looking for some guidance routes to follow. thanks

83pingpong

I agree that the valve timing must be wrong. But you do not need to remove the head to set timing.


Exposing the timing chain/cam gear just to see if the cam gear is in the right position does not involve removing stuff from the front of the engine, but you will need to remove the valve cover. Line up the dot on the cam sprocket with the top of the head. Consult your Haynes for exactly which side (left, I believe). If the crank position is also in the correct position when that dot is lined up (again, consult your Haynes), then you have the timing set correctly. If that test tells you that the valves are NOT timed, you can try to set the timing. Be gentle while turning the crank and cam into position, because you can bend a valve while doing this if you try to force the crank to move if it resists. At that point, you'll need to remove lots of stuff from the front of the engine, including the cam cahin cover on the front of the engine. Haynes will probably show the list.

If they are already bent...

The only way to confirm whether you bent valves is by pulling the head. There may be some evidence on the stems exposed (inside the valve springs). But the actual bends won't be visible from above (they typically bend near the valve). However...a bent valve will not return to full closed position, which would be obvious because of the much larger gap between the cam lobe and tappet. So you should be able to tell if valves are bent without removing the head.

gillesdetrail

iTrader: (1)

Once you have the timing figured out, test with a leak down test listening to the air hissing from exhaust port or intake port.

kawazx636

iTrader: (3)

For one, if you are rebuilding a 22R to stock specs, the ONLY source you should be using to rebuild these engines is the factory FSM. Here's the link to the 1983 FSM which will be good for everything on your '82 except for wiring colors:

https://www.dropbox.com/sh/5bvgv7x5y...BO_XOxwfa?dl=0

Download it and save it to your computer - I will be removing the above link after a few days to keep people out of my DropBox account.

Two, if this is your first time rebuilding an engine, make it easy on yourself and pull it out to correct your issues. Nothing is worst than having a bunch of crap in your way while you are trying to learn and correct something at the same time.

Three, your compression issue is likely from poor initial timing. There are two ways to fix this. You can take everything off of the front of the motor and try to do it with the head on the engine, but then you risk not getting a good head gasket seal when you re-install everything. Given your experience, I would recommend the alternative - take the head and oil pan off, then take the timing cover off (with the oil pump and water pump attached). If you haven't ran the engine through a heat cycle then your head gasket should still be reusable and if you need a new timing cover gasket you should be able to snag one from a local parts store. To be honest, I think it is easier to get everything off of the front of the engine with the head off anyway - after all, it only 10 extra bolts to remove to pull the head, but a lot less potential for headaches and leaks later on. From there you can set your engine to TDC on the #1 stroke, inspect your valves for possible damage, properly align the cam and crank timing gears and re-install.

Other possible sources of low compression are pistons and valves not being properly seated, but typically that would still yield some compression rather than zero compression. Did you have any machine work done on the engine? How much, if any, work was done to the valve train? Where did you get your rebuild parts from? More information and pictures would certainly help us help you diagnose the issue.

kawazx636

iTrader: (3)

Also, I have rebuilt all kinds of engines before and I documented my 22R rebuild when I did it. Check it out here:

https://www.yotatech.com/forums/f114...azx636-261494/

I will be moving this thread to the more appropriate Pre-84 Tech section so you get more hits and better information.