Help with Vac Lines

[Guest Roger NE]

Is there a diagram anywhere showing where all the Vacuum lines go on the 2JZ-GE ?

 

ALSO . . . there's an outlet pipe halfway down the block on the exhaust side of the engine, right at the back. Presumably a Coolant Hose goes on here . . . but where on earth does it go to?!

 

Hope somebody can help.

[Guest Roger NE]

Can nobody answer this?!

[Dnk]

There is a drain plug at the back of the block with a pipe coming out of it so i guess

you could mean that.

 

Page CO-2 has a diagram in the CO pdf

 

There are some diagrams for the vac lines in the TC pdf but not sure if

there detailed enough

CO.pdf

TC.pdf

Edited December 6, 2013 by Dnk (see edit history)

[David P]

Heater matrix return.

[hodge]

The only water outlet on the exhaust side direct from the block is the coolant drain. It's just a bolt that you undo to remove the engine coolant. As David says, the copper coloured pipe that runs from the back of the water pump housing to the rear of the engine, that outlet goes to the heater matrix.

[Guest Roger NE]

Many thanks guys . . .

 

Yes the outlet on the engine is obviously the drain plug ! So one hose I don't need to worry about

 

Almost all the hose connections to the car (Heater, Radiator, Brake Servo etc) are in exactly the same place on the 7M engine I'm replacing, so can use either the Mk3 or Mk4 hoses . . .

 

I'm still concerned about the VAC lines though, as I'm not quite sure where everything goes! (thanks for the PDF file Dnk, although that was for a turbo engine!)

 

I do have the TSRM downloaded, but none of the diagrams I've seen in that are much help . . . they kind of presume you have unplugged the VAC lines, so know where they should go back. In my case the engine has arrived with some missing, or unplugged because they go to external components . . . so I don't have much idea.

 

For the Mk3 somebody has come up with a simple diagram showing exactly what VAC lines connect to what, that somebody else has even colour-coded to make it easy . . . guess you don't have anything similar for the 2JZ engines?

 

There is a local guy who's offered to come round with his car when I'm ready . . . so guess I'll have to ask him to do that, and draw myself a few diagrams !

Edited December 7, 2013 by Roger NE (see edit history)

[Chris Wilson]

Take photos and I should be able to ID them for you Roger. You said GE before, is it an N/A or TT? or a conversion?

[thomo8568]

Hope this is of help. Less the EGR part.

[David P]

That diagram is U.S. spec and will get Roger confused.

[Guest Roger NE]

Well I've now sussed out where the various lines go, having looked at someone's engine installed in their Mk4

 

I know the Jap market N/A engines (like I have) never had EGR (good, as I would have removed it!) . . so there are no E and R ports on the throttle body

 

But that diagram IS useful (thanks Thomo), as the one VAC line I haven't sussed out is the one that I have seen on someone's car going from the P port, via a valve, onto the tree of metal vac lines that go elsewhere . . so I was wondering where that went!

 

(Presumably all 3 ports are the same, so they just use the one marked P to go via the Check Valve to the "Canister")

 

Well I don't have a check valve . . . or a Canister . . so presumably I can just blank it off (but what is the Canister for?)

[thomo8568]

On mine it opens the second butterfly valve.

[Guest Roger NE]

So do you mean it feeds that Vacuum Tank in the diagram ? And then on to operate the butterfly valve inside the Plenum that makes it switch between two separate intakes or one big one - presume that's what you're talking about?

 

And ALSO . . . where exactly is that "Vacuum Tank" ?

 

If it's off the engine somewhere, I don't have one ! (wonder if it will operate with the vacuum straight off the plenum? (That's how it works on the Mk3 7M engine)

 

Or maybe direct off that P vac port ?

Edited December 10, 2013 by Roger NE (see edit history)

[thomo8568]

It is fitted to the bottom of the intake runners. If you run it without one I think it will just open as sone as there is a vacuum build up and not at the point set by the ecu. Will like if I have a photo of location.

[David P]

Well I've now sussed out where the various lines go, having looked at someone's engine installed in their Mk4

 

I know the Jap market N/A engines (like I have) never had EGR (good, as I would have removed it!) . . so there are no E and R ports on the throttle body

 

But that diagram IS useful (thanks Thomo), as the one VAC line I haven't sussed out is the one that I have seen on someone's car going from the P port, via a valve, onto the tree of metal vac lines that go elsewhere . . so I was wondering where that went!

 

(Presumably all 3 ports are the same, so they just use the one marked P to go via the Check Valve to the "Canister")

 

Well I don't have a check valve . . . or a Canister . . so presumably I can just blank it off (but what is the Canister for?)

 

The coded vacuum tails are different sizes and different positions to serve different purposes.

 

The "P" tail is a very fine port close to the butterfly edge when throttle is closed and it's job is an idle control function which is plumbed to the vac tank via a solenoid.

[Stevo]

Hi Roger, my GE engine is currently out of the car and sitting on an engine stand in my garage if you want to come and look at it and see exactly where all the lines go, including the VSV fitment. Also have a load of pics on my phone I could show you or you could take some pics of your own away with you?

 

Drop me a PM if you are interested mate - I'm based in Swalwell near the metro centre.

[Guest Roger NE]

Thanks for the help guys . . although I'm still slightly confused! (and thanks for the offer Stevo, but Jonny brought his car round yesterday for me to compare, so sussed out where my missing lines go, apart from this one !)

 

So is the diagram posted by Thomo completely wrong? (I know these engines have no EGR)

 

That shows the line from the P port going through the Check Valve and on to the "Canister". That line is missing on my engine . . but on Jonny's it DOES go to the Check Valve and onto one of the metal pipes. (the far end of which I presume goes to the Canister)

 

If that's correct, presume I don't really need a Canister, so can just blank the P port off? (guess it's some kind of emissions thing)

 

Unless that diagram is wrong, surely the Vacuum Tank (which feeds the VSV that operates the Plenum butterfly) gets its vacuum from the end of the Plenum? (and I can see the horizontal plastic tube mounted under the Plenum, which I presume is the Vacuum Tank - all those VAC lines are intact)

 

So does that sound right?

Edited December 11, 2013 by Roger NE (see edit history)

[Chris Wilson]

That sounds correct Roger. The important things are the intake plenum butterfly and the FPR. You could delete the rest if you wished. If this is a turbo conversion you need to think carefully about what happens if "things" suddenly see boost. In particular be sure the brake servo check valve is boost compatible. Also ensure the vacuum storage tank has a one way valve so it doesn't become a *pressure* tank! Good luck.

[Guest Roger NE]

Thanks Chris . . . yes the lines were already in place for those . . . it was just the P one on the Throttle Body I was concerned about, so I'll just blank that off . . . the other missing ones were for the PAS Idle Up valve, but I know where they go now.

 

The only other thing I need to find is a VAC line to use for the Mk3's Heater VSV and also the Cruise Control VSV . . . guess I can just put a T piece in to tap into the one coming off the Plenum?

 

And no plans to ever fit a turbo !

[Chris Wilson]

Yes, just use a T piece, no worries. But NEVER tap into a feed to a fuel pressure regulator, ESPECIALLY on a turbocharged engine, you need to be as sure as possible something vital to the engine's welfare gets as good a chance of uninterrupted vacuum / pressure as possible. So minimize the chance of a vac leak from anything else plumbed into the same source by NOT having anything else on that tap. Same with MAP sensors.

[Guest Roger NE]

But NEVER tap into a feed to a fuel pressure regulator . . . Same with MAP Sensors

Thanks Chris . . . .

 

I thought I had this all sussed . . . but I've just been tracing the metal vac lines on the engine, and I'm still slightly confused!

 

I now see that the VAC port on the FRONT of the throttle body (coming off at 45 degrees) ends up going down to a little Blue VSV valve (underneath the rear of the Plenum) with a Blue electrical connector plugged in, the output of which goes back up the metal pipes and ends up on the "tree" (as I'll call it - a whole load of metal vac pipes sticking up) - in fact it goes to TWO of these, as one is tapped into the other.

 

On the diagram posted earlier, this is the Vac line that goes through the VSV on the middle right of the diagram. (but the diagram doesn't show where it then goes!)

What does this Vac line feed on the Mk4 Supra? (and what operates that switch?)

 

At present this goes nowhere on my engine, so presumably I can bypass the VSV switch and take it straight to my heater valve (which just needs a vacuum to work) and the Cruise control Valve (which on the Mk3 is fed from the same line) ??

Edited December 11, 2013 by Roger NE (see edit history)

[Guest Roger NE]

Hope someone can answer this . . .

[Chris Wilson]

You are worrying too much, so long as you have the right vac feed for the plenum divider, and the fuel pressure regulator nowt else really matters, cap the damned things off One will be a ported vacuum, controlled by throttle butterfly position, the other will be plenum vac. I would think..... I have some N/A engines here, but they all have the pipework off them. No N/A cars here at the moment, either. The "P" designated port on the EGR whatsit will be the ported vac, looking again at it. The hole will be fully or partially masked by the throttle butterfly when it's closed in the idle position. You don't need any of that junk unless you are a died in the wool green Maybe your engine is from a Lexus, I can't remmeber. Different markets had different emissions set ups. Expect to find anomalies to the Supra system. Just run what's actually needed. A heater water control valve and whatever would normally be fed from a vacuum reservoir, so the water control valve can't oscillate with manifold vac changes, but it won't be vital. Just get it in the car and worry about such trivia later

 

As for the solenoid valve under tha back of the plenum, isn't that the control valve for the plenum divider? N/A's are so darned reliable I rarely have to do anything to the peripheral stuff. If you capped everyting off save the fuel pressure regulator and any MAP sensor, it will still run OK. Just lose mid range torque, or top end power, determined by what position the plenum flap rests in.

Edited December 12, 2013 by Chris Wilson (see edit history)

[Guest Roger NE]

Well I appreciate it will run ! This IS a Supra engine, and yes, I will just cap off that P port on top of the throttle body (did that on my 7M-GE when I removed all the EGR rubbish)

 

But I'm trying to decide which VAC feed to use for my Heater VSV. On the Mk3 it's just fed from the Plenum, next to the Brake Servo vac feed . . . but the trouble is that on the 2JZ-GE the only small Plenum Vac feeds are to the MAP sensor at the back end, and the Fuel Pressure Regulator at the front (neither of which you say I should tap into)

 

PLUS it would be good to pick up some unused wires in the Engine Loom, as I still need a couple more (that I don't currently have) to interface with my MA70 ! (that's why I want to suss out where the wires to that Vac Switch go)

 

No, the Vac switch for the Plenum Butterfly is an Orange one, on top of the Vacuum Tank that feeds it.

 

This blue Valve switch I'm trying to identify is right at the bulkhead end of the Plenum, underneath . . as I say, its VAC line comes from just AFTER the throttle body, at the start of the Y pipes (on the front side of them)

 

Can't imagine what this is for, especially as it goes through an electrically switched valve. The output of that valve goes back to the metal pipes that go up to near the Fuel Rail, and there is a T-off, so it must feed TWO different things ! (although there are no vac tubes attached to mine)

 

I've searched through the TSRM, but can't find any reference to it . . .

 

Is that VAC feed from the start of the Y-pipe likely to fluctuate, compared to one from the Plenum? (obviously need a constant vacuum, as it keeps the heater hot water valve open)

Edited December 12, 2013 by Roger NE (see edit history)

[Chris Wilson]

Go for a plenum fed source, vac sources near a throttle plat are likely to fluctuate, and often they are taken from that region for just that region. Is this the diagram you are working from, it's from my paper copy factory manual? I just photographed the relevant page:

 

http://www.chriswilson.tv/2JZ-GE.JPG

[Guest Roger NE]

No, hadn't seen that diagram (although it's useful . . thank you)

 

The only diagram where I can see the line I'm on about is the one Thomo posted earlier (think it's from a sticker on the engine bay) . . . it's the Line coming out of the Y-pipe immediately below where it says "Check Valve"

 

As you can see it goes onto a Valve Switch . . . but wonder why, and where it goes onto ? (as I'd like to re-deploy the wires that go to that switch, if I can identify it!)

 

But anyway, I won't use that Vac feed for my heater then . . .

 

How about I tap into the Vac feed for the ACIS actuator? Presumably it would be better AFTER the Vacuum Tank? (guess that's there to stabilise the Vacuum from fluctuations still further)