Rough cold running

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Alan_M
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Re: Rough cold running

Post by Alan_M »

A quick way to test for an air leak is spray some thing like damp start, easy start or brake or carb cleaner around the joints with the engine running. If revs rise you’ve found your leak.

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Tanz
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Re: Rough cold running

Post by Tanz »

Hawaiis0 wrote:
Fri Nov 19, 2021 15:32
How does the crank case breather fit in? Is it still secure and together?
The green filter thing is in good condition. Will recheck the connections again.
Cheers, Phil
Never take life seriously, nobody gets out alive anyway!

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Tanz
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Re: Rough cold running

Post by Tanz »

Alan_M wrote:
Sat Nov 20, 2021 00:05
A quick way to test for an air leak is spray some thing like damp start, easy start or brake or carb cleaner around the joints with the engine running. If revs rise you’ve found your leak.
Good idea. I have some brake cleaner so will give it ago.
Cheers, Phil
Never take life seriously, nobody gets out alive anyway!

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Crowman30
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Re: Rough cold running

Post by Crowman30 »

Hi,
Hope this might help.
Image

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Tanz
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Re: Rough cold running

Post by Tanz »

Thanks for the info Crowman30

Tried to find a leak today but no joy. Disconnected the brake servo pipe at the manifold and blocked it off to take the servo out of the equation.
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This made no difference so I guess I can dismiss the brake servo as a problem. Also clamped the pipe that goes to the green breather filter using a brake hose clamp - this also made no difference.
Then I noticed that next to the distributer on a 'ledge' on the engine block there was a small pool of coolant. Seemed to be coming from the inlet manifold. Coolant passes through the middle of the manifold and feeds the rail that the thermal valves are in.
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If water is leaking from there then so must air. Also there is some black gunge visible in the joint between manifold and head as if a previous owner had sealed it with high temp sealant. I happen to have a gasket in stock so intend to remove the manifold with carbs attached and replace the gasket. Fingers crossed this might be the answer - watch this space :)
Cheers, Phil
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shaunw
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Re: Rough cold running

Post by shaunw »

Have you checked the brake servo one way valve Phil? When that fails it makes weird sucking noises. Mine had an air leak from the valve and it affected running though not the same symptoms as yours. Could also be the hose or hose connection at either end?

Edit: sorry Phil, didn't read your last post! Obviously not servo related.

Shaun

Pete Boole
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Re: Rough cold running

Post by Pete Boole »

Be prepared to see some corrosion around the coolant transfer holes Phil - manifold may need skimming (but hopefully not the head).

Pete

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Tanz
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Re: Rough cold running

Post by Tanz »

Pulled the manifold off this afternoon. There was a proper gasket in place. Just got to make sure nothing drops into the head when I scrape off the old gasket.
Second picture below just about shows the small pool of water near the distributor that was there before removing the manifold.
Interesting that along the bottom edge of the mating face on the block, there is a long distance between studs. The gasket has two holes in it along the bottom edge that are not used.

Image

Image
Cheers, Phil
Never take life seriously, nobody gets out alive anyway!

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