WilberF

I'v done som searching here and elsewhere online. No clear answer. So I recently bought a 1999 RX300. I'm attempting to change the timing belt. (I've done TB's before). When I line up the cam marks, the Cam mark is 3 teeth off. I've rotated the engine several times with the same result.
The car drove sluggishly before and accelerated poorly.
I'm wondering it the crank teeth is off by that much, if the car would start in the first place. Wondering if I just needed to rotate the engine some more or something.
Can I line up the crank mark (i.e. rotate the crank 3 teeth and the rear can sprocket back 1 tooth) and put on the new TB? Should that work?
In the pics the rear cam looks to be a teeth off and the crankshaft 3 teeth off. The red marks were there before..

manianac

Yes you can move the cams/crank with the timing belt off. Be careful, as the back cam will want to move without the belt (the timing mark has the cam on the top of a lobe). Depending on what new belt you're using, just use the timing marks on the belt to install, and then verify with whats on the cover.

salimshah

Just be careful when you move the 3 independently. The cams have only point that you need to match, but the crank has to be on the compression TDC cylinder #1. [4 stroke engines have 2 TDC exhaust and compression].
Once the belt is off, I suggest that the crank should not be spun [if you must then do in multiple to 2 complete turns].

You can put the main pulley and bottom cover to see the TDC.

If the belt was off, it could have been put on incorrectly, but it does raise a suspicion about the tensioner. I would replace it too.

Before attempting to start, make sure you can spin the crank shaft 2 + turns without any mechanical binding [you will have to fight the compression is the plugs are installed].

Salim

WilberF

I did re-align the timing marks and install new timing belt kit. The car started just fine. It idles much better now. Haven't driven it yet though. Now onto the next problem (sounds like it might be a tranny issue)...after the test drive.
Thanks for the responses!

lexina

Did you re-align the timing mark on the crack shaft counterclockwise or clockwise?

salimshah

Hopefully WilberF will answer with what he did.

If you ever encounter such a problem, then you have to analyze your situation. Like if the engine was running but not perfect then you are in the ball park of the mark ... a few teeth away.

You can turn the crank backwards, but it recommended to turn clockwise. Exaggeration here ... if you are 1/4 over then instead of going back 1/4 of turn, do a 3/4 + 1 turn.

One can remove the valve cover and observe that cam lobes would not be pushing #1 valves on TDC of compression stroke. For RX you can open bank2 valve cover [just because it is easier] and look up firing order and then determine the crank position.

If you put the crank 360 degrees out, the engine would not fire, but no damage should happen.

Salim

WilberF

You'll note from the 3rd pic that the crank mark was 3 teeth in the counterclockwise direction. I just turned the crankshaft clockwise to line up the mark and installed the new belt...
I note the info on the proper rotation procedure. Thanks.