Confused Recirculation Valves 1995 E150 Looper

[s.wxman]

I am trying to check the accessible recirculation valves on the V6 looper. The manual only goes through the procedure for cyl 1. When at idle I get bubbles in the glass of water from the hose removed from the no 1 cyl block that is still attached to intake manifold. I can easily push alcohol through the nipple on the block. According to manual that means cyl 1 checks good.
I get same results for the cyls 3 and 5, so I am assuming they check good.

When I went to other side of engine I couldn't get to the fittings on the block. No big deal. I disconnected hose from the nipple on the manifold. Instead of bubbles from the opening on the manifold, I would get bubbles from the hose that was still attached to block. I could not push alcohol through the nipple on the manifold (which seems correct). I haven't yet tried pushing alcohol through the hose still attached to the block nipple on the even side cyls. Guess I should go do that.

Anyway. Do I have a problem or am I doing the test incorrectly on the even side? Or is this test even meaningful other than for cyl 1? (I am using page 2-40 of my OMC manual. I am definitely getting bubbles out of the block fittings and not out of the manifold fittings on the even side.

Thanks to those in the know
Wxman

 

[s.wxman]

Bump!!
Sorry, but this one has me stumped.

 

[s.wxman]

OK. Looked at it some more. One old mechanic told me he didn't always have good luck with the running test I was doing (according to manual). He said to check that the nipples on the block were open both ways and that the nipples on the manifold were blocked 'in', but 'open' out. (I should be able to suck air out, but not blow air in. By this method I have two bad check valves on the manifold, cyls 2 and 4. They are both 'blocked' in both directions.

Now the new question. How should I go about taking these out to clean/replace?? Should they pull straight out, twist and pull...? I don't think they are threaded.
Heat?? Force?? What works?
Wxman

 

[s.wxman]

I am learning, but it is a slow and difficult process. The visible nipples I have been messing with are just that, nipples. They are not the check valves themselves. They are however press fit and came out with careful force. I now understand the actual check valves are at the other end of the passageway on the interior side of the intake area.
I plan on doing as good of a decarb as I can in hopes the two valves open up. Not holding my breath though.
Any hints on removing carbs/throttle bodies on the port side to get to these valves? I have manuals, but I only want to take apart the minimum amount to get to these valves. Can I remove the carbs/throttle body in one piece? Will I need to remove any of the center stack items like VRO or vapor pump/box?
Any hints from those in the know appreciated.
Thanks