4age 20v silvertop cam belt stripped teeth. New belt on, not firing.

[adamaw11]

So my timing belt gave way, pretty nasty, stripped the teeth off the belt.

I've replaced the belt now, I used the Gates T081 which is 111 teeth, same tooth profile, but not actually the silvertop belt, I've read that it can be used, same number of teeth.

I've got the cam timing marks lined up, on the cam gears and crank timing pulley.
free upload

I've checked that I've got spark while cranking.

Pretty sure there's fuel, can smell it when injectors plugged in and plugs out.

It cranks over, seems like its getting compression, but just doesn't want to fire up.

Not sure where else to look, I don't see how the cam timing could still be out.
Although the 20v st is non-interference, I'm wondering if some other damage has occured.

Could the distributor have somehow gotten out of sync from the cam-belt stripping?

[shrike]

I thought the silvertop was an interference engine?

I would do a compression test followed by a leak down test, Chuck a timing light on it as well and make sure the timing is right

[adamaw11]

The compression test seems to show: 40psi 90psi 90psi 90psi which seems pretty low I guess, indicating either valve damage, or the cam timing still out.

I might try taking the belt off again, plumbing compressed air into a cylinder, then manually turning the cams to see if there's a point where the cylinder seals up.

[adamaw11]

For future reference, I got the engine started by just cranking it for a lot longer. After about 5seconds of constant cranking, it seemed to fire slightly a couple of times, then eventually fired up and ran.
So the cam timing was indeed correct.

After running it a while, getting to operating temp, then stopping to do another compression test, the results showed:
158psi 154psi 155psi 153psi

Doing a cold comp test I guess effects the results, but I didn't think it would be that much.

I wonder if after the timing belt failure, some valves got stuck open slightly, and just needed a good crank to free them up again?

[shrike]

Glad its sorted now and yeah possibly could have been some stuck valves

That comp test is still a little low, how many km has it done?

[adamaw11]

Its got 182000 ks on it. I'm not sure what they're comp is meant to be now actually, I thought the numbers looked pretty decent, consistent at least.