I dont understand how it would run good when it warmed up if the timing belt was off a tooth. There must have been something else wrong which was fixed when you redid the t-belt. Maybe a bad connection with the coils or cam sensors. Did you change any other parts along the way? When my belt jumped a tooth it ran like crap for 10 minutes, then died and wouldn't start. But, either way, glad you got it fixed and running good.

 

No parts were changed at all! All I did was remove the covers for both cams, the fan bracket, and the timing belt tensioner to move the left cam just one tooth clockwise. I've checked the cam sensors before I did this and they were fine!

 

I'm a bit of a simpleton and a Lexus newbie/wanabe but how the heck does a timing belt just randomly skip a tooth? Is something else wrong that would cause this or i this common with theLS engine?

 

if the belt is worn, the timing can jump a single tooth, but also common is a timing belt is mis-installed one tooth off on a just a single cam

 

How did you "move the left cam one tooth" without removing the timing belt? Something just doesn't sound right. But, either way, it doesn't matter b/c it's running good now.

jb2wheels; When the belt is worn and old (it's weak) it stretches a tiny bit and when the cam turns at such force it jumps a tooth. Or, as in one of my cases, when the cam seals are leaking the oil gets on the belt and made it VERY slippery which made it jump 2 teeth. That's one reason why the cam seals should always be changed when doing the T-belt. Also need to be careful while bleeding the coolant ontop of the thermostat b/c coolant can leak down inside the timing covers and do the same thing to the belt.

 

You were dead on with that diagnosis I just browse and read the forums just collect info in case something goes wrong on the car. For the most part I know what the problem is right away. Thanks to the OP for coming back and confirming what the problem was and the related fix.