I have a 91 acura integra with crower 404s and crower dual valve springs/retainers. I put the motor together drove it maybe 10 minutes and it jumped timing at a low rpm. It does not have any bent valves, but i went to run it today and it did the same thing. I put a new timing belt on but did not change the tensionor. Obviously with the timing belt being loose after jumping timing i assumed it was the tensionor. Im replacing it tomorrow i just want to get some imput of other possibilities of what could cause this before i chance bending a valve.

 

bump, i know someone can help me.

 

Improperly set tension is the culprit. Also, check the cam gears for tightness.

 

how should it be set, we stated to tighten it, moved the pulled a tiny bit (to set the tension) then tightned the pulley. The tensionor still holds some tension when i pulled the tbelt off, but its done it twice. It keeps moving. I doubt the bolts not tight enough.

 

You turn the crank CCW three teeth with the tensioner loose and then tighten the bolt. The belt should only deflect about an inch if it is tight enough.

 

yup thats how it was. I have done many timing belt jobs that way, never a issue.

 

It will stay tight, run it, check it still be tight. Its when it gets revved up into the high rpms its like it slow loosens. Basically, is this a sign of a bad tensioner?

 

The tensioner bolt is slipping or it is physically damaged.

 

Sounds to me like the tensionor wasn't torqued down enough... could also be the spring.

 

does not look like the bolt is spinning. Just like the tensionor is slowly moving and cause the belt to become looser and looser.

the spring would not tighten the belt enough to i put something under the tensionar to get the belt tight then tightned the tensionor untill i could not anymore.