Timing Belt Incorrectly Installed By Previous Owner

[g9s0x]

I am changing the timing belt as the intake cam is off 3 teeth in the counter-clockwise direction (i believe that is advanced 3 teeth??) and i think it is causing my idling problems. I am not making enough vacuum at idle and it will try to stall out on occasion. I believe that the intake valves are staying open too long and causing too much valve overlap, thus a loss of vacuum similar to as if I had high lift cams.

My question is that the crank and oil pump marks are right on and the exhaust cam is where it should be but the intake cam is off 3 teeth. To re-set do I need to remove the belt and turn the intake cam clockwise 3 teeth to get it back inline with the exhaust cam? I have done 2 timing belts before, but on cars that had marks that all lined up properly. I want to make sure that doing what i said above is the correct way to restore the timing marks to where they should be. Thanks for any help guys!

Chris

 

[SpeedFreak03]

Yea you are right, the timing belt being off will cause idle (and other) problems. I don't see why your method wouldn't work (I've never changed a TB on a DSM but that's how I do it for other cars when the ticks are wrong). You mine as well put a new timing belt on, these cars need them changed more frequently then others. Good lucK!

 

[tsunari]

http://www.vfaq.com/mods/timingbelt-2G.html

 

[g9s0x]

thanks for the reassurance. i was almost certain that is what needed to be done as there is really no other way around it. just wanted to make sure before hand as i have never come across this issue before. the vfaq is nice, but does not explain this situation.

one more question, just for general knowledge sake, since the intake cam was 3 teeth off in the counter-clockwise direction (form the perspective of looking at the cam gear from the driver side) would that mean it was advanced or retarded 3 teeth? My guess was that it would advanced since it is opposite of the CAS. you turn the CAS clockwise to advance base timing so turning the cam gears counter-clockwise would advance? just want to clear that up. thanks again for your help!

 

[RoasT BeeF]

Counterclockwise would be retard. The belt runs in a clockwise direction anything backwards (counterclockwise) is retard and anything forward (clockwise) is advance.

I would read the vfaq no matter what. The cam marks are supposed to line up even with the top of the cylinder head. Thus simply moving the intake cam 3 teeth so that it lines up with the exhaust cam is not the answer....the exhaust cam could be off as well. Make sure to get the balance shafts in phase too.

 

[Defiant]

Originally posted by g9s0x
I believe that the intake valves are staying open too long and causing too much valve overlap, thus a loss of vacuum similar to as if I had high lift cams.

Not open "too long", just timed wrong. Duration can only be changed with grinding. Overlap can be mucked-up with timing.