Closing in on a 4.6
 

Monte - Indiana - nice 2meet cha ,)

Bought this land yaught (gotta love 'em!) 3 years ago with 35K on her - paid WAY 2 many $ 4 it...

Finished replacing the plastic, fantastic intake jokeafold today. Long time coming. Results as expected - almost.

Still has a slight stagger just off idle. Starts funny - cranks a while unless you touch the gas.

Everything says PCV valve - as in, wrong one. Parts stores sell me a "universal" thing that "fits" every small block ford v-8 made since they had pcv... CLOSE, BUT NO BANANA...

I'm like, soooo close now. Anybody been here and figured this out?

PCV Valves for Grand Marquis
 

Hello, Art, and welcome to the Mercury Forums --
PCV Valves for the Grand Marquis ain't all the same -- and you didn't give the YEAR of your ride, SO -- I searched 'em all --
1980 - 2002 = Motorcraft - EV98-B
2003 - 2004 = Motorcraft - EV258
2005 - 2006 = Motorcraft - EV273
2007 - 2009 = Motorcraft - EV279
2010 - 2011 = Motorcraft - EV281
Motorcraft parts available at - RockAuto.com
If yours is Electric, make sure that the power is getting to the Valve.
Good Luck !
https://cimg9.ibsrv.net/gimg/www.mer...d8bb92bac3.jpg
95 MERC Engine Bay

congrats on the find!

Made a lot of progress today. Went to NAPA and found they had a "better brand" of PCV valve. Problem with the cheap crap is the plastic top thingy (snout - whatever) is so tight you end up bending the el-cheapo thing while removing it. Causing the valve to leak. Their better brand was better both ways - stronger and it was much easier to remove the plastic snout. So that made a difference - one more vacuum leak found and slain :)

No more stutter on takeoff. Still started funny. As I am ancient, I remembered something we used to call VAPOR LOCK. It's when a gas line gets so hot the fuel evaporates inside it. I removed the "hat" from the motor and bled the fuel rail. Just undo the cap for the pressure test and GENTLY push the tire style adapter. It hissed, first time, and no fuel came out. BINGO!

DO NOT do that with the motor running! That's an engine fire, right there! Start it, shut it off, bleed then repeat, until no more air comes out - just fuel. I had to do it only once.

So now it's like, 99%. Still stumbles when idling in gear. Might be it doesn't like the plugs I put in it - Bosch, thin-wire, double iridium. The IAC and the EGR are brand new - bought them before I learned about the manifold thing...

And, so it goes - rofl!