Camry keeps jumping time

[Fortified Souls]

What part needs to be replaced if the car keeps jumping time
The time was set correctly and it ran perfectly until we put everything back together and it wouldn't start. This scenario I believed also happened last night however, at the time we had the harmonic balancer off and we thought that it was the reason it skipped.
Any help would be appreciated

[Oceans]

My first look would be at the timing belt tensioner.

[Fortified Souls]

I was telling my dad the same thing should we just go ahead and replace it with a new spring and everything?

[71Corolla]

The spring does absolutely nothing to keep the timing belt tensioned, zero. It is only there to put the "correct" tension on the belt during assembly. After you tighten the bolt on the tensioner pulley, the spring could be removed and it would not make any difference.

[Fortified Souls]

I don't understand what the problem is then? The belt is tight and on tdc then when you turn it over it becomes loose and the timing is all out of wack... any suggestions I'm following the factory service manual procedure.

[71Corolla]

Wrong timing belt? Not routed correctly? Other wrong parts or not assembled properly? Not much else can go wrong it's a pretty simple system.

Post some pics.

[fenixus]

if the tensioner spring was old/worn or of wrong type in first place when initially tightening the belt then it MIGHT have played its role in improper belt tension after tightening the bolt down.

how old is the belt (might be stretched), is it OEM? when were the idler and tensioner rollers replaced last time, was it together with new belt?

I don't see how HB pulley could cause the belt to jump ... maybe I'm missing something. belt is driven by crank timing pulley which is separate from the HB (tightened HB holds it in place though).
when HB goes bad it wobbles (outside part starts separating from inner ring) usually and makes some extraordinary noise also affecting PS and alternator/ac belts tension.

if car is confirmed to jump timing, then I would just go ahead and get new OEM belt (Mitsuboshi is best, but Dayco or Bando are all right OEM brands as well) along with new NSK or Koyo (both are OEM brands on those) idler+tensioner (and a new OEM spring), though the last ones I would get aftermarket, OEM are seriously overpriced, e.g. from www.drivewire.com

[JohnGD]

The timing belt should be tensioned at 45 BTDC (not TDC as in earlier engines). You may want to get a new spring just in case. Manually tensioned timing systems are always a pain. Do follow instructions to the letter.

It's always a good ideal to replace the oil seals (cam, crank, oil pump), pump o-ring, idler and tensioner pulleys, the spring, and even valve cover set.

Originally Posted by Fortified Souls

What part needs to be replaced if the car keeps jumping time
The time was set correctly and it ran perfectly until we put everything back together and it wouldn't start. This scenario I believed also happened last night however, at the time we had the harmonic balancer off and we thought that it was the reason it skipped.
Any help would be appreciated

[Fortified Souls]

Originally Posted by JohnGD

The timing belt should be tensioned at 45 BTDC (not TDC as in earlier engines). You may want to get a new spring just in case. Manually tensioned timing systems are always a pain. Do follow instructions to the letter.

It's always a good ideal to replace the oil seals (cam, crank, oil pump), pump o-ring, idler and tensioner pulleys, the spring, and even valve cover set.

Tomorrow I'm going to buy the timing belt kit. The engine needs no seals because it was recently rebuilt about 25k miles ago. The belt snapped due to a screw falling into the cover from the camshaft position sensor. Neglected to change the belt after fishing out the bolt due to budget and planned on doing it later. We got about another 10k out the belt before it snapped and now the tension is not working properly and we think its the spring but were going to change out everything fresh for good practice.

[JohnGD]

Some timing kits come with 2 springs, like the $54.79 Dayco kit:http://www.rockauto.com/catalog/moreinfo.php?pk=1306950

Just have to pick the right spring.

Originally Posted by Fortified Souls

Tomorrow I'm going to buy the timing belt kit. The engine needs no seals because it was recently rebuilt about 25k miles ago. The belt snapped due to a screw falling into the cover from the camshaft position sensor. Neglected to change the belt after fishing out the bolt due to budget and planned on doing it later. We got about another 10k out the belt before it snapped and now the tension is not working properly and we think its the spring but were going to change out everything fresh for good practice.

[Fortified Souls]

Bump two days later and it's all fixed!!! My dad replaced everything when I was at school but still was having problems getting it to start but then I came home and we did it one last time a it purred to life!. I'd like to thank you all for your insight and I am honored to be apart of this Camry community! The Car for it's cooperation its getting new tires tomorrow to go along with its new brakes and timing belt/tensioner etc. lol

[fenixus]