Count up and Name the Vacuum Hoses in our NA

[ProwlerGT]

This thread may be relatively short, but I can find no "summary" reference anywhere in my searches so I want to create one.

1. Basically I'd like a COUNT and the NAMES of the vacuum hoses in our NA's. I have the vac hose kit from IPO and I want to install it and I don't want to miss any.
2. Also, if someone want to explain: What is a vacuum hose reduction? Is that basically just shortening the length of the vac hoses or actually removing some vac hoses from the picture or both?

FYI - I know this post shows my ignorance of how vacuum in an engine works or is setup. Feel free to explain all you like.

I'll start it off:

Count and Names of Rubber Vacuum Hoses

1. Brake booster vacuum hose connection - Rubber with built-in check valve
2. Fuel pressure regulator hose - Rubber
3. Evaporative Purge Control Valve - Rubber (4 total hoses) - 1 small one stems out of the throttle body looping back to a metal vac line attached by the TB bolts making a "U" shape, 1 stemming from the metal vac line to the evap solenoid on the firewall, 1 stemming from evap solenoid to under backside of upper plenum, then 1 stemming from left front corner of engine (standing facing the front of car) to evap canister which is underneath the radiator overflow container.
4. Bypass hose - Rubber - from upper plenum area to air intake pipe
5. Vac leak zones - Besides the hoses the following zones could be leaking in order of air flow: Gaskets/Seals along air intake pipe to TB, TB butterfly plate shaft seals, IAC/ISC seal, FIAV seal, BISS seal, TB to plenum gasket, VIC motor seal? (on upper plenum), Upper plenum itself as it is more than 1 piece, upper plenum to lower plenum gasket/seal, lower plenum to engine gasket/seal
6. Cruise control vac pump - Not connected to manifold plenum (only mentioning cause its vac hose) at all and probably is ok cause it doesn't see much action, but if your cruise control isn't working this could be why. A separate vac pump activates to utilize cruise control and thus the more vacuum it puts the more/less pull on the accelerator cable.
   

EDIT: Completed the above list of possible air leak zones. If I have missed any someone please post to this thread so I can update the list.

[SOHC3000GT]

I'm pretty sure vac hose reduction is removing all of the hoses near the EGR vavle.

[Yume]

I don't know about you N/A guys... BUT

Vacuum Hose Reduction is removing lines and associated components.

On the Turbo cars we totally remove the EGR with block-off plates, and thus capping off 3 ports on our throttle body, capping the evap port on our gas tank, pulling the evap fuel line all the way down the chasis, and pulling the evap canister. We also pull every solenoid except fuel pressure, and we end up with a couple vacuum lines...There's also lines you cap on the intakes, or buy an intake kit without the nipples welded on them (saves money)

2 wastegates to the boost controller
1 line from our Y-pipe to the boost controller
1 line from our BOV to the boost controller, T'd off into the intake manifold
FPS in (from intake manifold)
FPS out (to FPR)

Then you just T in your boost gauge as you see fit...

For an N/A, to do a vacuum reduction... you'll have to do EGR block-offs and then you can ditch some of the other stuff on there. I'm not too sure, but try and find a stock diagram of everything... someone must have a CD of the factory manual with the picture, or check under your hood...

Are you doing this without an EGR block-off kit?

[ProwlerGT]

Thats good to note. I guess I should state that I have a hybrid year vehicle and this is a FEDERAL SPEC NA engine. I have no EGR. EGR's are on all Turbo's in general and all NA's that are CALIFORNIA SPEC.

10/18/06 - EDIT: PDF page 511 / Section 17-51 from the Chassis manual shows that all 1996 Non-Turbo Models (FED and CALI spec) and UP have EGR. I guess my hybrid year of 1995 Fed spec is special for whatever reason and just didn't have one.

[SOHC3000GT]

Originally Posted by Yume

Are you doing this without an EGR block-off kit?

I've already got the EGR block off plates installed, I just don't know where to begin the vac reduction.

[ProwlerGT]

Ok, I've just spent a long time (hours) looking through the entire chassis manual for the phrase "vacuum hose". Since it seems (as I've been looking through the manual) "vacuum" is shared in various components throughout the engine references to "vacuum hose" are all throughout the manual and not in just 1 spot like I'd love (IE: An explicit vacuum section). I did however find this:



I put the red lines in the graphic and added the "NA" statement. Having seen that troubleshooting list for vac leaks it of course implies that vacuum is shared in those 6 areas of the engine. For me (and all FED SPEC NA's at least up to 95) there are only 4 areas of "vacuum" concern since I have no EGR and no Purge Control Valve as well. Those two features seem to be on TURBO and/or CALI SPEC NA models only.

References found in the manual:
PDF page# 285 - Shop manual page#13A-181, Item #9 - Fuel Pressure Regulator
PDF page# 390 - Shop manual page#13A-286, Item #3 & 4 - Fuel Pressure Regulator (different view)
PDF page# 392 - Shop manual page#13A-288, Item #3 - Throttle Body
PDF page# 435 - Shop manual page#15-17, Item #4 - Intake Manifold Fuel Rail
PDF page# 488 - Shop manual page#17-28, Item #2 - Vacuum Pump
PDF page# 913 - Shop manual page#35-87, Item #5,6,&7 - Brake Booster

One may be fooled that there is a fuel pressure solenoid in the NA engine, but from what I see in the manual there is not. If someone would like to correct me here if I'm wrong, be my guest.

Suggestion if you are doing this and you are new to it and working alone: Only physical inspection will tell you if the hoses, pipes, or lines are rubber vs metal and in cases like the check valve which is setup differently for AWD vs FWD you can't put a new hose on that because the check valve is press built-in with the rubber on that line so if for whatever reason your check valve is bad or the hose is leaking you have to buy a whole new one which is going for $24.57 right now at Rockville Mitsu. The way I'm approaching this is that I've printed out the 6 pages of references from above. Take a highlighter out and highlight everything on the diagrams and take it with you to the car. It looks like in my case (I think) that I may end up with extra silicone vac hoses left over, but we'll see.

Also, while snooping around in CAPS and some info I had from Rockville a while back I found this too:



The 3 boxes selected in RED represent the following:
12433AQ1 MD192076 HOSE & PIPE ASSY,EMISSION VACUUM $ 30.19
12981 1 MS632392 HOSE,EMISSION CONTROL EQUIP $ 30.68
12433AP1 MD192081 HOSE & PIPE ASSY,EMISSION VACUUM $ 12.29

So, under the hood I go inspecting all these lines and seeing what in my silicone hose kit from IPO I can replace. Maybe I'll do a PDF if this all goes well. Who knows.

[ProwlerGT]

I love it when I start up a thread and answer my own questions. LOL

[ProwlerGT]

Question: I put in the new IPO vac hoses and as I was doing so I noticed that the inner opening diameter of the hoses was about half that of the stock hoses. Will this cause a problem? or will it improve vacuum in the engine?

[roguetrip]

it won't hurt anything, won't increase pressure, just don't kink them, got any pics?

[ProwlerGT]

Originally Posted by roguetrip

it won't hurt anything, won't increase pressure, just don't kink them, got any pics?

There are some pics towards the end of page 8 of this thread.
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