Cam timing

[chu346]

during the last few days I have been taking apart my engine to fit a new head and camshaft. I've been snapping bolts all over the place and now that i've finally got everything back together the car won't start.

It seems like the timing is out, but when I checked it, it was all spot on. So I thought that i'll move the cam by one tooth to see if that'll work, but no. There is fuel getting in, a spark to ignite it and I pressed the pedal to give it air what else does it want.

Any ideas people? I'm all out and I can't think straight anymore as i've banged my head on the corner of the garage door and have a big lump on me head and feel abit

[Motorhole]

Have you done a compression check? That seems to be the one obvious thing missing from your equation...

[6inline]

We can't help you whithout a bit of more information. what exactly do you call 'all spot on' and what engine is it, first?

[chu346]

Sorry guys it's an M20 2.7

Motorhole I don't have the tool for that.

6inline I call spot on, when both the timing marks are in the exact place as they were before I took the head off.

BTW it's a 282/272 camshaft if that makes any difference?

[Simon]

Is the lower pulley on in the right place? I made this mistake when I rebuilt the top end on my sport, took me ages to realise!

I'd put mine back 1 turn in the wrong direction, engine will turn over fine, but it will not start if it's in the wrong place.

[Simon]

Sorry, I meant to say the vibration damper, also make sure the pulse sensor is clean and mounted OK.

[Demlotcrew]

You need to TDC the crank to the head, remember the crank does two revolutions to every one of the camshaft.

Andrew

[chu346]

I'm sure that on my engine I can only put the bottom pulley on one way as there is a little dowel that has to be located correctly, otherwise the bottom pulley won't go on.

I've put the crank to TDC acording to the official marking and when the head was off I also checked that the marking was correct and the no. 1 piston was at TDC.

[Demlotcrew]

can you see the T/O mark on the bottom pulley?

Andrew

[chu346]

yes, that's what it's set to.

and the top is set to the mark at approx 2 'o' clock.

[Demlotcrew]

And when you crank it by hand it always ligns up?

Andrew

[ROC]

Have you got the valve clearances set correctly? If not the valves may not be closing completely, the engine will not build up compression and will just keep turning over.

[tonyppe]

how have you tested the spark?
is the crank shaft sensor all back on and connected?

even if the cam timing wasnt spot on it would still run, just diferently.

also, how have you checked that fuel is getting in?

>tony.

[tonyppe]

p.s. if thats a brand new cam, i hope you have put plenty of cam lube on there.

[chu346]

After fiddling with it for almost the whole of today and yesterday, it finally works. I think I must have knocked something.

I've changed belts etc. many times before due to rockers snapping so I do know what i'm doing, that's what puzzled me.

Now then, onto fixing all the pipes i've broken!

Thanks for all your help.