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Installing Vacuum Blocks 84-93 T-1 thru T-4

2M views 239 replies 60 participants last post by  Syleng1 
#1 · (Edited)
I would like to make a thread for the membership on installing a vacuum block on all TD's from 84 -93 with all of the different engines and years.
Show how you installed it, what parts were used and links of where to get the parts needed with pics of the completed job.
Also if you added a CAI show/tell how you ran the lines including PCV for the deleted airbox.

Below will be the index of year/engine and will be listed by post #.

Post #2) 90 T-4 (VNT)
Post #5) 87 T-2
Post #8) 88-89 T-1/T-2
Post #28) 91-93 T-3
Post #33) 84-87 T-1
 
#88 ·
Sorry, I thought that I had answered this?? Guess not. Probably why I haven't seen any
updates!!!

Ok, I have a line going to the baro that feeds the map so I should be ok there.
Same deal with the FPR.
Not sure where the feed for the gauge comes from but it works fine so I'm guessing
that should be ok too. Probably comes from the rubber dist. "thingy" that I'm trying
to replace.
The brake booster has it's own feed from the intake so that should be ok as well.
Don't think I have a BOV, it's a 90 2.5 T1. I also do not see a BOV connection on the
vacuum line diagram.
As for the "mbc/grainger or solonoid-----wastegate can" Not too sure about this??
The diagram shows a line going from the Waste Gate Solenoid to the waste gate, and into the turbo. The diagram also shows a line coming from the turbo to the air cleaner
and then to the cruise control.???
Also a direct line to the purge solenoid.

The only line I have removed was the larger line coming from the TB. The check valve
had one of the nipples broken and was leaking like a sieve!! I noticed that on some of the pics posted around that this line was capped at the TB. The car seems to run fine
like this. Do I need this line??? Looks like it goes to the vapor canister...
 
#89 ·
"As for the "mbc/grainger or solonoid-----wastegate can" Not too sure about this??"

DCTZ wrote this up. Quite informative.

2.2 / 2.5 Liter Engine Turbo Bleeds

#1 Bleed
A bleed is when the air system has an alternate route to let air escape so that the device being controlled (wastegate) will see less pressure. This will make the wastegate open fully at say 10 PSI instead of 7 PSI. Most of you do a bleed combined with the stock solenoid bleed.

#2 Stock Solenoid Bleed
The stock wastegate control system uses the solenoid to create a bleed. The solenoid opens and closes real fast at different rates (duty cycles) to create more and less bleed on the wastegate. The more often the solenoid is open, the more it bleeds, and the less often the wastegate is open, allowing more boost. If the solenoid is open less, the wastegate will see more air pressure, and be further opened, allowing less boost. The solenoid is controlled by the computer by the feedback it gets from the MAP sensor. If the solenoid is stuck closed not allowing a bleed, or if you connect the vacuum line directly to the wastegate, the boost level should be about 5 PSI max. So if you only get 5 PSI your solenoid is likely shot.

#3 G-Valve
A G-Valve does not let air escape but holds it back from the wastegate until a certain pressure is obtained. Then the valve opens allowing the air pressure to open the wastegate. There is a bleed which is not the major controlling factor on the wastegate side of the G-Valve that allows for the wastegate to close again after the pressure closes the G-Valve. If this very small bleed was not on the wastegate side, the wastegate would remain open and you could boost no more than 5 PSI. So maybe some of you consider this small bleed on the wastegate side a bleed that controls the boost? The vacuum line never sees this small bleed.

The 1st 2 systems (bleed and stock solenoid bleed) always puts some pressure on the wastegate allowing it to open a little at low boost. This is what causes some of the turbo lag. A G-Valve does not let the wastegate open at all until is sees the set pressure so it has less lag.

I tossed in a quick layout of the bleed method in use by your car.

I hate to disagree with NAJ, but if you look at your vacuum diagram and follow the PCV valve towards the air cleaner box you will see it hooks up to the air cleaner box. This circuit is how the PCV valve sees a vacuum any time the engine is running, and even if the engine is in boost.

When I converted my T1 over to a T2 and installed a cold air intake turismolover22 posted this drawing so I could retain my Cruise control, PCV valve, etc..

Also inside the air box where the PCV enters is a small air filter. Most people forget they have one and never change it.

I also am posting a pic on one of the many ways to install a g-valve. You can delete and plug off where required the hose from the wastegate solenoid valve and the small 5/32" vacuum fitting on the turbo it's self.

Sorry for rambling!

Dennis
 

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#94 ·
I left my vapor canister hooked up. Did not see any reason to disconnect as I was told in another thread that it would not help with increasing /decreasing my engine HP.

Dennis
 
#96 ·
Look under the hood at your vacuum diagram. If it looks like the one I have here it is a T1.

Dennis
 

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#98 ·
Before you gut your existing vacuum system you will need to keep all your orifices and check valves. The vacuum lines running to your air cleaner box should be left alone.
If involves a vacuum ejector which will drive you nuts if you gut it. See this previous post for NAJ http://www.turbododge.com/forums/f4/f14/344996-what-vaccum-ejector.html
Their are lots of vacuum blocks out their. Came across this post about a good one yesterday. http://www.turbododge.com/forums/f4/f15/398989-new-vacuum-manifold.html. I did not use any of them. I drilled and tapped my vacuum fittings into the intake manifold (see pic).

Dennis
 

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#100 ·
It appears nobody has posted on a 91 2.5L T-1 but the install is basically the same.
The vacuum block will be installed to the intake manifold either by a hose from your existing vacuum port or with fittings.
You will also need 5/32" and 7/32" vacuum lines, connectors, check valves, orifices, clamps/wire ties.
From the vacuum block you need to run new lines to the...
Baro Solenoid
Fuel Pressure Regulator
Boost Gauge(if equipped)
Purge Solenoid

You will run new lines to the Turbo/Wastegate and from the Turbo to the Vacuum Ejector(you will probably want to re-use the vacuum ejector as it is unless the hoses are really bad)

Follow the vacuum diagram to replace all other hoses using the factory check valves and orifices if they are there, if not use new ones.
Connectors will be your choice on how you want to route everything but you will need some basic connectors.
When all done use clamps or black wire ties to secure the ends of the hose on the connectors to be sure they are tight.
 
#103 ·
Eliminating vacuum circuits will not make your car go any faster. Check valves are flat on one side and conical on the other, airflow is from the flat side to the conical side. Orifices can go either way, if given the choice I point mine so the direction of airflow pushes the little metal insert into the fitting, mark each size/color from where you removed it, if you need to reinstall it later. Eliminating orifices can create funky results, and will do nothing to make your car faster.
 
#104 ·
I am about to install a vac block on my 85 daytona, t2 swap. I will be getting a 3-bar in the mail soon with pigtail from FWDp and wiring it up, along with a stage5 87 cal. My questions are;
1. Do i need to have check valves or orifices between each item (ie; Boost gauge, map, etc.) and the vac block?
2. Will I run a line to the stock baro then map, or right to the 3 bar from the vac block?
 
#105 ·
All check valves and orifices need to be installed.
Check valves are installed in circuits where you do not want boost to enter.
Orifices are used to slow down the vacuum/boost to a component so it does not see full impact immediately.
You will need a vacuum diagram for the year/system you are running.
The vacuum source runs to the baro solenoid and then from baro to map.
 
#109 ·
Hello, I recently purchased a Vac block off ebay for my 89 Voyager. I also just put a new motor in it that i purchased from another member. I have a question about connecting it.

Do i just connect the main feed line to the vac block to the line with the blue arrow or is that setup all wrong?
Thanks
 
#110 ·
Some prefer to connect directly to the intake, but you can use a length of hose from the fitting on the intake to the vacuum block, no problem with that.
Look at the picture in post #8 on pg 1.

Your vacuum lines are routed wrong BTW, the pipe coming off the intake manifold is supposed to be routed to the PCV valve.
 
#117 ·
You must be referring to the 4 fuel injectors that go into the manifold with the fuel rail.
Those have to remain or the car will not run, it will have no fuel.

The only thing you are replacing with a vacuum block is vacuum lines, nothing electrical.
the new vacuum lines will run over top of the fuel rail, between the manifold and valve cover.

 
#120 ·
They are wires that the computer uses to turn cycle the solenoid on /and off.
 
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