I was playing with my cam gears today and I think i might have made the T-belt skip a tooth. I first retared the intake cam by 5 marks (1 mark on cam gear = 2 degrees of crank rotation). This lost power, so then i advanced it 4 degrees. This made some power and added ALOT of lope to the idle. I then tried to retard the exhaust cam 2 degrees, but it was hard to move and saw the t-belt get slack. With the intake +4 and exhaust -1 the lope was real bad. The car stauled at stops and cel 11 came up. I then put the exhaust back at 0 and left the intake at +4 degrees\advanced 2 marks.

But the idle is still real bad. No cel though. I have reset the computer and the idle is still bad. The car seems like it has good low end but the top end is gone.

So how can I tell if the belt skipped a tooth or what??

By the way i have crane 16s with oversized valves. I expect some lope but not this bad of a lope, considering at 0\0 the car barely made a lope at all.

im not sure about the crane 16s, but retarding your intake cam 5 degrees seems alot to me. Sounds like a bent valve, but dont take my word for it

If it skipped a tooth the only way to see is to check the timing. Its quick if you left your cover off, but if you left your cover on then its a pain in the ass. 10 degrees seems like alot to play around with. If the timing is still on do a compression test. Bent valves will show up as low compression.


95 Eclipse RS : 5 speed
15.7 @ 87.9mph
Jeep TB writeup - http://www.dimensia.com:81/jimbo/JeepTBfor2gnt.html

the belt did skip a tooth. I set everything back to 0/0 and the cel came back on. So i advanced the exhaust cam 8 marks which is 16 degrees. This setting fixed all my problems and made the car run like it did before i did any cam timing changes.

I then advanced the intake cam 2 degrees for more power.

So you didn't redo timing you ust adjusted the gear?

The timing belt should not skip a tooth if it's under correct tension, no matter how much playing you do with the cam gears.

I would tear down the timing and redo, check the hydrolic tensioner to see that's it's still good.



Exile Racing Technologies: http://www.exileracing.com
una salus victus

Well i dont have the time right now to tear down for a t-belt redo. Advancing the intake cam give good low end power but the top end just falls on its face. Retarding the intake cam (which increases overlap) makes the idle even smoother (which is strange) and increase the top end alot.

If you retard the intake cam you are removing overlap. Advancing the intake cam increases overlap. Exhaust valves open first, then intake. Retarding the intake cam makes the valves open later and ther is less time where bothintake and exhaust valves are open.

From the sounds of you really need to tear down the timing. I'm betting the exhaust cam isn't set right either from the symptoms you are describing.



Exile Racing Technologies: http://www.exileracing.com
una salus victus

^-- What he said...

Advancing the cams does nothing for top end, but hurt it. You'll build more cylinder pressure by advancing the intake cam: more torque, less top end. Retarding your exhaust cam will give more overlap, not your intake cam, and will give more top end. If you're exhaust cam is off, your iginition and injectors are off too due to the exaust cam sensor.

Tear it down, fix it, it only takes a few hours. You'll know where you stand after that, instead of this guess work which could cause all sorts of problems if a piston hits a valve if it slips more.