Vacuum lines

[DR86FT]

Hi guys I'm trying to setup my vacuum lines but I want to get it right.

I have a 4agte 16v with ITB's with a GTIR plenum also t3 itb adapter
ECU is a 440 adaptronic basic select


I am running a brake booster, fuel reg, ISCV 20v PWM version, MAP sensor on the ECU, Boost guage.

Andy from adaptronic says the brake booster will interfere with the MAP reading and I'm guessing the ISCV will too.


Can anyone help me out with this situation how to plumb it all up?
Also I have 1 vacuum manifold and I think I may need 2 of them.

Cheers Kaan

[SamsTA22]

Don't worry about the ISCV, when the ecu is in idle mode, it should be ignoring the MAP reading.

You could sort of say the same of the booster, depends how bothered you are by it (and how often you brake and accelerate at the same time).

If you were keen, you could copy the way the factory 20v manifold does the booster. Just drill and tap two threads in the adaptor manifold (Cyl 1 and 4), and hook them up with vacuum lines to the booster separately.

[DR86FT]

Do you mean the iscv won't interfere or don't install it, also my car has air conditioning and I have taken off the vacuum advance thingo.

I don't mind doing things the right way and neat.
I've been trying to look for vacuum diagrams on 16v with itb's but not much luck only pictures not clear enough for me

[SamsTA22]

I meant that the ISCV wont interfere with the tune.

The ISCV lets air into the vaccuum manifold, with will change the map sensor reading. But this isn't a false reading, you want the MAP sensor to pick up the difference so the fueling is accurate during idle.

The booster, on the other hand, will change the map reading when you press the brake pedal. This could lead to inaccurate fueling during idle if you start pumping the brake when your car isn't moving. I just wanted to point out that you don't necessarily have to do anything about it. Most of the time when you pump the brake pedal, the accelerator is off, and you are therefore in fuel cut.
Not only that, but you should be most concerned about accurate fueling during full throttle open loop conditions. That's not a point when the brakes are commonly pumped.

But, that isn't to say it's never an issue. Like, for example, bedding in brake pads. I'm not sure how people have solved this issue for 16v ITB conversions. But in the factory 20v setup, the booster has a source of vacuum independent of the vacuum manifold by being connected to holes in the runners on cyl #1 and #4. The fuel regulator and the smog gear is also run from seperate vacuum holes. But everything else, including the ISCV, is connected to the one manifold.

Also, I'm using a silvertop as a reference, so I can't speak for the blacktop's map sensor, I'm afraid. If I were to use one on my silvertop, I would connect it directly to the vacuum manifold, though.

[DR86FT]

Ok so I never put it altogether. Been a bit slack but I want my car running so does this look right? Will it work? Anyone know if there is anything wrong with this diagram apart from the port on the vacuum manifold not being used lol

[Skylar]

Looks ok to me bar a few things:
The black line should go to to wastegate actuator - not comp. cover.
I personally would run the MAP signal from the vacuum block, not from one cylinder. It'll probably be fine but depending on the sampling rate and sampling point, you can get varying MAP readings for single cylinder compared to the averaged signal.

[Sam-Q]

It's also good to have something to dampen the pulses going to the MAP sensor as well.

[DR86FT]

So if I take the MAP sensor vacuum from the pic on the right it will be from all 4 cylinders by itself.