styleruk
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New video by Simon Tyler
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2.25 petrol rough idle
- Thread starter styleruk
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I think you'd be looking at three, maybe four teeth for twenty degrees, but why not have a look at the valves for #4 at tdc on #1. See how far it is either side for them to start moving.
styleruk
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Now that's using your nogin. I'll get a bit of paper and sketch which one should be where to work that out
styleruk
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Ok, as usual, timing cover off shows a completely different scenario to what I thought. At first, I think the cam cog is 180 out, secondly, it looks also a tooth out of 180 too. I'm gonna have a think about it over lunch before changing anything. The marker on the cam should align with the top stud hole and the keyway should be 180 to what I have, that's what I'm seeing.
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Just to confirm, which valves are fully closed?
styleruk
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#4 are rocking,#1 fully closed
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I'm tending to agree. On this screen I think I can see one tooth out. (And ignoring the 180).
Ok 2p time.
Your cam sprocket mark doesn't look quite 180 out (i.e a tooth or 2)
The TDC mark you have is it really, You need to dial gauge down the plug ole (or with the head off) for TDC when it peaks and then when it starts to decrease then split the diff.
I remember some talk of some cams being timed 180 out (cant remember where or what engine) and if your valves are closed on cyl 1 then it maybe the case
Sometimes its easier to do it by how it should be, if you are unsure the marks are correct.
I.E find TDC, find closed valves on 1.
J
Your cam sprocket mark doesn't look quite 180 out (i.e a tooth or 2)
The TDC mark you have is it really, You need to dial gauge down the plug ole (or with the head off) for TDC when it peaks and then when it starts to decrease then split the diff.
I remember some talk of some cams being timed 180 out (cant remember where or what engine) and if your valves are closed on cyl 1 then it maybe the case
Sometimes its easier to do it by how it should be, if you are unsure the marks are correct.
I.E find TDC, find closed valves on 1.
J
styleruk
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so, I've moved the chain one tooth round so the line is at least dead on...even though it's 180° out. Next step will be to pull the cam shaft but before that, I'm putting it back together this weekend and testing it. If it's solved the rough running then great, if not, then it's time to take the cam shaft out. That's definitely wrong in that the keyway is 180 out. But I'll see this weekend I hope.
styleruk
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An interested thread found here by my brother... (he too can't get any sleep wondering why a cam would have a 180 out key)
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Valve/Cam timing Petrol 2.25- am I over thinking this??
Here is the old cam which is I hope the same as the new, Number one lobe lined up with the keyway (this I have checked with new one) Number 4 is 90 deg to number one. As the keyway is aligned with the P on the sprocket number one lobe is where the P is (or should be). Still confused here
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styleruk
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Right, put it back together and it's still rough, however, instead of the timing being an inch or so (nowhere near the scale) after TDC when running, it's now an inch or so before TDC. If I rotate distro to get it to run the best I can it's mike's out still! Very odd.
So, I took the distro out and it has one of these to convert it 90deg. It's not there in the manual, so it's evidence of something wrong.
I feel next step is pulling the cam shaft out.
So, I took the distro out and it has one of these to convert it 90deg. It's not there in the manual, so it's evidence of something wrong.
I feel next step is pulling the cam shaft out.
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I don't see any value in removing the camshaft.
When did this idle roughness actually start?
When did this idle roughness actually start?
So 1 tooth made no diff except to "looked out" On the mark, Which mark?
I have no idea what that bit is except it goes to the dist drive but it really makes no diff. Maybe the dist drive cog needs shifting to get you to the correct firing position if you cant do it with turning the dist.
I am with @boguing , no need to pull cam.
The engine can be timed correctly with no marks at all, sometimes following marks and believing them gets us to here.
So I would make a proper TDC mark. put it back together in the correct position, then maybe look at the fuel side. You say carb was/is good. But you have all you need to make it mechanically right. so its the other 2 components, spark and fuel.
J
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The distributor drive dog can only be there to get the height right? Why it's rotated is interesting, but as you say, doesn't matter. There isn't anyone watching that would stop 'a friend' from putting the distributor roughly where the body looks right (and will adjust without fouling) and shifting the leads around to suit.
styleruk
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I'm assuming it's there to stop it fouling on the block, used to have this issue with a rootes engine I built.
styleruk
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The distro is new and does what it should. Ie, fits, rotates, sparks etc... but I'm all ears for other thoughts.
549611 Drive Dog Distributor land rover 2.25 / 2.5 Petrol
549611 Drive Dog Distributor
www.turnerengineering.co.uk
So the drive dog is correct.
But is the drive cog in the correct place if it runs out of adjustment? But then to confirm that a good TDC mark is needed.
J
