Timing Belt Problem

[christiane]

As some of you may recall I have been having some problems getting my car back running. I BELIEVE I have isolated the problem back to either the cam angle sensor or the crank angle sensor. So, I decided to go ahead and repace both. Being that my car is a 95 it has the poorly designed cam angle sensor thatr equires you to remove the timing belt in order to change the sensor. I attempted to do this first without removing the exhaust cam. That did not work, so I took the timing belt off. (I forgot to set it to TDC). So without having the motor at TDC and having no timing belt on it what are my option to get the valve timing back within spec without destroying the valves in the process? I know the motor wasnt turned far after I removed the timing belt, but how can I make sure everything is in phase? TIA for any help. (I REALLY want to get my car running again, I am laid off for the next two weeks and would love to get a chance to see how the upgraded suspension is going to handle (new teins, RMDSM sway bars, poly bushing and new engine mounts).

 

[gamiller31]

If you have no reference on where the cams are in relation to the crank, the safest thing to do would be to unbolt both cams, so that all valves are in their seat, then put the crank at TDC, then bolt the cams in at the correct spot, then replace the Tbelt.

 

[blackGSX2g]

Your cams have marks on them so you know where to set them for TDC. Align the notches on the sides of the cam gears, and make sure the dowel pins are facing up (12 o'clock)

If you don't know where your pistons are at in relation to each other, before you move the cams make sure your pistons are in the middle of the stroke (even with each other).

A good way to tell this is to put 2 rods through the spark plug holes and turn the crank until both are dead even. Once they are even, spin your cams until they are almost lined up and all the valves are seated. Then spin the crank so that cyl 1 is at TDC and the crank timing mark is lined up. Once everything is lined up, your motor is properly aligned for the timing belt install.

When you actually go to install the belt, you may need to move the cam gears a few teeth off so that they line up when you put tension on the belt.

 

[christiane]

Thanks for the replies guys. My main problem is that I need to verify that the oil pump and balance shaft are in phase.
When I first removed the cam gears they did kick if the engine were at compression could this have bent a valve? If so how can I check it to prevent catastrophic failure when I start the motor? Again thanks everyone for the information already provided.

 

[bloc]

blackgsx2g is right on the money for how to phase everything so that you dont risk bending a valve. having the balance shaft and oil pump out of phase wont risk hurting anything if you try and turn the crank over by hand. phase in the cams first, then do the oil pump and balance shaft.
get the crank so that all the pistons are even (using the rod method is a good one, the other is use the timing mark on the crank to get the engine to TDC, then turn it 90 degrees. it doesnt have to be exact, 45 degrees from TDC on any of the cylinders is more than enough to clear the wide open valves) now turn your cams to their #1TDC alignment marks, then turn the crank to TDC, then align the timing marks on the oil pump.


as far as testing it to see if anything is wrong so far, get it all put back together and do a compression check. this should expose any bent valves.
generally as long as you didnt turn the crank hard while any of the valves were wide open or close, you wont have hurt anything. the cams tend to "snap" to a position between lobes that is pretty safe as far as valve to piston clearance is concerned.