Low vacuum with no leaks, correct TDC, and ignition timing

[Immortality]

Well you have something hooked up wrong because at idle there should be vacuum on the distributor advance module.

Different locations on the intake manifold provide different levels of vacuum. The vacuum tree on the rear runner will provide a more constant high vacuum source which you need to keep the brake booster happy.

For manifold vacuum readings you really need to measure vacuum at the common plenum which is under the carb.

Ported vacuum is used by the various switched on the engine to limit vacuum advance on the distributor in a poor attempt to reduce obnoxious gasses engines produce before the advent of unleaded fuels and catalytic converters. The down side of these measures (reducing ignition advance) was that it also killed engine performance.

 

[the_boozer]

plug the vac advance onto the ported vac point on the bottom of the carby and block up every vac leak is what most blokes do. Does the centrifugal advance work?
advance it up till it pings then drive it and knock it down till it doesn't. In the blue motor system there is no vac advance until the throttle opens along with what ever the emission lock outs do piss them off they don't do much it will run all right with out them.

 

[sundaydriver]

Here's a couple videos - @immortality @EYY @greenacc - just to illustrate what I have setup.
As you can see - and as @the_boozer pointed out - there is no vacuum registering on the vac-advance port unless you give it throttle.
The other video is just a quick overview of where all the hoses are connected, and where things are blanked off - the early evap switch hole is blanked off, so and had been bypassed - you may be able to see something I've screw up?
You'll also see that faulty solenoid mounted on the water pump - which i have bypassed already (running the vac-advance straight to the carby.)

 

[Immortality]

Forget the ported vacuum **** as it is part of the old school thinking of anti-pollution crap.

What Boozer suggested is to run without any vacuum advance and re-time the distributor to suit, this is common on performance engines but it will require re-timing the dizzy and to get the best performance altering the timing curve in the distributor which is a bit more advanced engine tuning again.

Try this,

1.Set your base timing to 8° BTDC on the dizzy with no vacuum connected.
2.Connect manifold vacuum (from the base of the carb) to the distributor advance. Measure your manifold vacuum from this same source.
3.Now reset your idle with the carburetor idle jet and idle speed adjustments.

For now forget about all those other vacuum hoses and fittings.

Take for a test drive.

 

[sundaydriver]

Try this,

1.Set your base timing to 8° BTDC on the dizzy with no vacuum connected.
2.Connect manifold vacuum (from the base of the carb) to the distributor advance. Measure your manifold vacuum from this same source.
3.Now reset your idle with the carburetor idle jet and idle speed adjustments.
For now forget about all those other vacuum hoses and fittings.
Take for a test drive.

Ok will do.
Sorry, just to confirm.
After setting the timing (vac-advance disconnected), I connect the vac-advance straight to that barb on the right hand side of the carby (in the video - the one that's showing 15/16 vacuum)? Your wording reads like I should test vacuum from that same point - but I don't have a T-joint, so can't do both at same time.

And do I just leave the other port disconnected - the one on the left of the carby that only has vacuum when under throttle?
Shouldn't I cap it? Otherwise it'll be a vac-leak when I throttle?

 

[Immortality]

Yes.

Yes, block the ported vacuum port so you don't have a vacuum leak when you crack the throttle.

 

[gtrboyy]

If threaded into waterways the tree at front & middle of head is all pollution crap & silly things that won't allow vac advance untill certain temp...as said most of us bypassed that crap.
Don't worry about ported vac either.

Tree at back off manifold use for vac advance & economy gauge if you want...large hose for brake booster obviously & will be 1 left for trimatic/modulator usually have restrictor looking hole in it.

 

[EYY]

Take your vac reading off the manifold itself.

 

[sundaydriver]

Aaaaaaaaaaand it's flooded

Seemed to go OK until that point though - think it was a bit too rich to begin with - so might be onto something.
Have the plugs out now and cranked it over with the choke propped open and the acellerator floored for a bit. Will let it sit tonight, clean the plugs and try again tomorrow.

Once I get it started again, I'll give it another go with the re: bypassing that ported barb on the carby.

With regard to cutting out the remaining emissions stuff - It's just the EGR thermal switch left. Do i just cap off the articulator and that barb on the carby, or just bypass the switch and run a hose for that barb to the articulator?

 

[Immortality]

I would cap off any unused vacuum port on the carburetor and vacuum trees to ensure no vacuum leaks.