DaX

iTrader: (1)

Well, I have been trying to figure out a way to get a dedicated port on my IM for some time now, without having to remove the damn thing and drill/tap a hole. At first I was going to use the port where the PCV ties in and just let the PCV vent to the atmosphere, but now I think I've found a different way.

In the picture below you'll see the sensor thing - HELM calls it the Starting Air Valve, and it supposedly comes only on A/T models of the B18A1. I don't know if it is present on any other IM. There is a small vacuum line [which I don't have] that runs to the intake pipe, and the fat vacuum line runs to the TB. If you remove both of these and crank the car, it runs no differently...it does NOT suck vacuum. I'm pretty sure the fat vacuum line is fed pre-throttle plate, as this would mean it does not suck vacuum, and the HELM says, "additional air from air cleaner" and points to it. The only difference I noticed when running without either vacuum line is when you turn the car off there is a slight chirp at the end of your engine spinning down, as the vacuum is lost and the spring takes over, opening this valve. This also brings up the question of what happens in boost. This little valve opens is what happens and bleeds boost out if you're not running the fat vacuum line and recirculates boost pre-throttle plate if you are running the fat line.

I am going to make a flange that will go over this hole and has a place to attach a 1/4" NPT fitting [I'm going to use 1/4" NPT x 3/8" Hose Barb for my vacuum manifold feed]. There will be a groove cut in the back for an o-ring, which you can get from your acura parts dealer for less than $2. I'll be getting a quote from my machinist this week on it. If anyone is interested, I'll post back with pricing, and order multiples.

Here you can see the valve removed, and you can see where the other end of the fat vacuum line runs. It doesn't hurt to leave this port open.

Here is a shot of the back of the sensor. I took measurments with calipers and drew it out.

The o-ring you'll need is #11 in the picture below:



Modified by DaX at 7:33 PM 6/2/2004


Modified by DaX at 10:15 PM 1/23/2005

DaX

iTrader: (1)

If anyone is interested, let me know, I'll be getting a quote tomorrow more than likely.

DaX

iTrader: (1)

Drawing complete, sent to machinist, should have a quote by monday.

SJP0tato

I was thinking of doing that exact same thing, only a little more simplified. Rather than making up a flange, I was thinking of just tapping the hole for 1/8" pipe thread, and getting a barbed fitting that I could slip a piece of vaccum hose over then route to the vaccum distribution thing. Only problem I was having was I couldn't fit my tap in there with the intake manifold, but I'm sure anyone with a halfway decent set (one that wasn't made in the early 50's like mine...lol) could tap that with the 1/8" pipe thread & use a threaded barb to attach a vaccum hose to.

Also, if you're running boost it would be a good idea to cap off that extra fitting on top of the intake manifold. Otherwise you'll be losing good boost through there (since it's before the throttlebody). I've gotten little vaccum-caps before at my local napa parts store for like $0.50 apiece, they're usually used for carbs the guy behind the counter said. Just a thought.
Ryan P.

DaX

iTrader: (1)

Yeah, I'll definately cap that port off. I was thinking of just tapping the hole, but it's a pain in my *** to take off my IM, and I am pretty sure I can get the flange made for cheap.

agrabau

Just drill it and tap for 1/8 NPT barb fitting it takes like 2 minutes. Hold a vacuum on it to get the chips. The chips are soft alu anyway they won't hurt anything. (should one fall in)

DaX

iTrader: (1)

No thanks, I'd rather not risk it.


Modified by DaX at 10:16 PM 1/23/2005