Offroad use only setup for elimination of vsvs

[CharlieS]

I know, there are a bajillion threads on this, and I've read a lot of them. I can't wrap
my head around the actual setup.

I have a '94 with PAIR. I have zero concerns about removing the PAIR shutter valve (and moving O2 sensors to the exhaust manifolds - I have two O2 sensors in hand. I have a Hudd Expo kit in hand too, but don't mind if I just use the jumper and skip the rest. I am ambivalent about removing the EGR setup other than the PITA factor of installing a lower block off plate.

I would like to remove as much as possible of the spagetti of vacuum hoses and switching valves.

This is a dedicated trail rig, so I don't care much if it is not factory.

My state doesn't do visual inspection onvehicles this old.

I will save the parts I remove in case I ever need to go back or sell.

Does anyone have pictures of their setup without vsv for egr, etc. Like the most simple setup possible.

Ok, I'd like to retain the charcoal canister part, if possible, but it won't bother me much if it has to go. My 200 has a LRA that vents to atmosphere, so I'm already on the environmental naughty list.

 

[LandLocked93]

One data point, I removed the PAIR, blocked off the exhaust ports, and looped back the regulator on top (plus a plug).
Left everything else in place.
Not sure how much of that spaghetti is still in use after doing these mods. Hadn't really thought about it but I am curious now that you bring it up.

 

[Desert Dino]

I did all of this when I bass lined my rig, removed PAIR EGR VSV and EVAC canister
Builds - Build Thread - my Enola Gay FZJ80 1994 - https://forum.ih8mud.com/threads/build-thread-my-enola-gay-fzj80-1994.999495/post-11273483

and

Builds - Build Thread - my Enola Gay FZJ80 1994 - https://forum.ih8mud.com/threads/build-thread-my-enola-gay-fzj80-1994.999495/post-11275583

the best mode I did, EGR in hot countries will degrade your No 6 and 5 cylinder

PAIR removal is easy all you need are 2 block plates with 2 gaskets and that's all. Block the exit on the air filter housing.

You may want to replace the bypass water line to the new one piece steel pipe from 95-97 engine as I did.

I O2 sensors were left in the original position until until had to cross Zin flash flood to reach the pavement and go home



I got water into O2 sensor connectors, bad idle, lost power. had to dry the connectors with compressed air, so I moved the O2 sensor to the vacant PAIR position and all is milk and honey

 

[CharlieS]

Well, I have it apart and am trying to suss it out and think through it logically.

The whole under plenum vsv and vacuum hose setup is bolted to the bottom of the plenum with four (12mm head) bolts.

There is one vacuum line that passes through a steel vacuum hose that comes through the upper plenum.

The line through my plenum was rusted internally such that I couldn't even pass a thin wire through it. I think I wasn't getting any vacuum... So, there's that... I used a very small drill spun with my fingers to open it back up to verify that it was a pass through.

The top side would normally go to the EGR vacuum modulator from a vsv for egr on the underside.

 

[CharlieS]

I'm eliminating the coolant circuit through the throttle body and capping it at the water pump and at the other end (which should be near the PHH, but I haven't located it yet). I bought the caps recommended in a prior 'mud thread and some Breeze clamps (not the Constant Torque ones). I think I'll just leave the ones on the intake and plenum open, since they don't go anywhere. Anyhow, I didn't buy any caps, so they'll remain open for now.

Edit, ppost capping photo below.

Edit - I don't know what the nipple below goes to. Both of the coolant lines go to the bottom of the throttle body...

On top of the intake are three forward facing hoses, and out if the rear there are two:

The two on the left of the above photo (pointing toward the rear if the motor) go to the EGR stuff. These could be looped back, capped, etc. if the EGR stuff is removed and block off plates installed. Or kept intact with the Hudd Expo bits.

The larger one on the right (pointing toward the front of the motor) goes to the top of the valve cover. This will remain intact.

The medium and small lines go down to the hydra of vsv valves under the plenum.

I think it is the two hard lines in the upper right corner of this photo.

I'd like to just cap these, but have no idea what that will do...

 

[CharlieS]

If one were to remove the EGR valve, this is where you'd put a block off plate in the plenum:

Keep in mind that this leads to somehow capping or removing and blocking off (with another plate) the other end of this EGR pipe, and it is in a spectacularly hard to read area with the engine installed (above and slightly aft of the PHH). I won't even attempt a picture.
This tube is for the pcv, and flows back into the intake through the casting:

Coming through here:

This goes two places theough hard lines into the belly of the vsv hyda. Eventually one side ends up at the fuel pressure regulator, via a vsv.

Oddly caled a gas filter, and only specced for up to '95...

Note that the 96-97 specs a gas filter with only one tube.

I think one of these lines ends up going through a fuel pressure vsv to the fuel pressure regulator. I'm not sure where the other goes, somewhere into the vsv hydra...

And this goes to the brake booster:

 

[CharlieS]

Looks like there is a TVV (thermal vacuum valve) down in the bowels of the engine bay. Sounds like it has a heat sensitive bimetallic strip that either vents to atmosphere or closes to contain vacuum, maybe?

I'm going to speculate that this can be left disconnected/capped or looped with vacuum line with no difference in outcome.

What have people done with that? Does it need to be looped or capped? Do people remove it and block off the hole? Can the vacuum lines just be removed and leave it open to atmosphere? Any advice?

 

[CharlieS]

Doing some searching here on mud there seems to be differences of opinion about whether to leave the fuel pressure vsv setup intact or to go straight from the gas filter on the plenum to the fuel filter. Any fresh insights on this one?

 

[CharlieS]

Not super fancy work like a "keychain", but free to me and should get the job done.

 

[CharlieS]

Some caps and I pruned some hard line with the dremel.

They're cheap dorman caps, and prior mud posters have said they do not last long, but they'll do until I have a chance to find something with more longevity.

 

[CharlieS]

No more PAIR.

I'm going to toss O2 sensors in here, once I replace the studs and get new nuts:

 

[HejsanKwaheri]

Thank you for the detailed post. Have you had any issues since deleting everything? Also what did you end up doing with the “gas filter”? Did you loop the two outlets onto themselves or where did you connect them to? Thank you.