2.25 petrol rough idle

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Here's a link to a video, before you slate me... Yes, I'll put the tappets back. I set them cold and now I have a sewing machine effect, that I'll put back but this video shows the drop in revs, even when revving.
 
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.
 
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.
Now that's using your nogin. I'll get a bit of paper and sketch which one should be where to work that out
 
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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0461beb7-f83d-4540-ae81-f53ea5b4d20a-1_all_23614.jpg
 
With #4 rocking and #1closed, piston at top and the cam cog mark is dead aligned to the reference stud hole, (albeit 180 out), pop the cover back on to ref the TDC and i get this. I think the chain is a tooth or 2 out and i should ignore the 180 thing
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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
 
Yep, did the piston up thing. Definately cam shaft 180 out. But maybe it's only a tooth out and an odd cam. Book reference a dual keyway sometimes, but this has one. I'm going with the 1 tooth out and I'm not going to install it as per book, it'll be 180 out
 
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.
 
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)

 
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.
1000001586.jpg
 
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.


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 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
 
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
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.
 
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.
I'm assuming it's there to stop it fouling on the block, used to have this issue with a rootes engine I built.
 
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