Possible vacuum leak

[shaunb]

[MOOSE]

[shaunb]

[Roger Miller]

shaunb,

2 minutes after removing manifold to head u will see where its leaking.

Some of the inlet manifold gaskets are way thin these days.

I glue [yellow contact cement] gasket to manifold and grease head to gasket face.

I don't use studs, to mount manifold as its too hard to get assembly on/off in one piece like u need to.

I also grease all the soft mounts, surfaces, before fitting.

Give it a go.

[joe84]

a few things might be worth looking at as i've been playing around with my 45 dcoe i think you said they were 152 model ? if they are i noticed with mine that they come out with a fuel enrichment/cold start thingy on top towards the manifold on mine it was bottoming out on the manifold even with the thicker soft mounts and this was put together by a carby shop which i suspect is giving a flucuating idle so i filed the manifold to suit, also following a book i have it recommends to tap and plug with grub screw the cold start ports incase there not working anymore which are the 6mm holes under the butterfly i guess these could also leak air if the carby itself was not sealed properly, i did all the above today but didn't have enough time to start it maybe tomorrow

[Roger Miller]

joe84,

Yes your spot on right about some manifold needing clearance.

Heres my old Lynx unit.

[joe84]

also try winding the idle by pass screws right in (the ones with the locknuts) these let air by pass the butterfly when it's fully closed (on idle) might have to adjust your idle after

p.s what rpm does your car idle at shaun the one with the 949 cam as mine sounds like it has to idle pretty high i don't have a tacho on it atm tho so not sure of rpm