Hi all. Im trying to install a vacuum gauge for my b18b1. I tried the charcoal canister to throttle body line, it barely read -2 on the gauge, so i tried to run the line that comes from the back of the head and goes into the intake manifold, and i get -3 on the gauge, inches of mercury. am i doing this right? or is my gauge faulty.

what line do i tap into if those aren't correct?

 

Tee into any small vacuum line coming directly off your intake manifold.

 

notaracist, thats what i did. i believe its the pcv valve? its only a 1/4 inch vacuum hose, comes out the back of the head towards the center, and attaches into the very front of the intake manifold. i just tucked all the wires and hoses away and im gonna go on a test drive, but im upset that this isn't working well

 

...The PCV valve? You realize that's...no, of course you don't. That's a one-way valve. You can't use that. Use a VACUUM LINE off of the intake manifold. Your fuel pressure regulator line will be easiest.

 

okay so i hacked up my pcv valve line, can i just let it vent to atmosphere for now until i can get to a parts store to replace it?

 

 

okay i got a new pcv line, hooked it up, then tapped into the really thin vacuum line that goes into the bendy piece on top of the fpr. the other end runs into the manifold.

now its sealed up tight but only reads -10 on the gauge ALL THE TIME, whether at WOT or decel. im so confused.

 

Is there an unused cruise control nipple on the IM?

 

it says keihen NR-1 on the housing of the thing i hooked the line up to. I googled that and it's a japanese FPR, so i know I hit the right vacuum line

 

cruise control was deleted from this car, but it originally came with it. where do i look for that?

 

Actually, I don't think it has a vacuum assist.

The FPR tee should be good.

 

but the needle doesnt swing to 0 on WOT or drop to -20 or so when on decel (closed TB) it literally stays at -11 in hg all the time no matter what i do, even with the car off.

 

Sounds like a bad vacuum gauge or you broke it. Is it a cheapy gauge?

 

its fairly cheap. are you sure its the gauge? could it be a mechanical issue? I'm gonna go outside and take a picture of the setup so we can verify its installed properly

 

Nah, the gauge is toast.

 

Is this a pod or dash mount vacuum gauge. If so, what brand? Why have you decided to install a vacuum gauge?





eH.

 

 

It's neither. I custom rigged the spot where the cruise control button used to be, widened it out, wired it up to ground and accessory positive, wired the gauge up, fed the hose through the firewall, routed it up behind the steering wheel and connected it to the gauge, and pushed it into the dash.

 

I put a voltmeter on the other side where the dash dimmer was.

 

 

You may have kinked the hose. Check under your dash or pull the gauge back out.





eH.

 

alright im gonna do that now

 

So the vacuum line wasn't loose, or kinked or anything. However i noticed that when i went to pry the gauge out, the neeedle fell to 0 immediately. i started the engine and it stayed at ten. i then messed with it a little bit and figured out that the plastic cover for the gauge is probably rubbing against the pivot point on the needle, if i pry it out a little bit it rotates freely! At idle i get the following readings on an 165000 mile engine:

WOT = 0
semi-warm idle = roughly -16 steady
part throttle = somewhere between 0 and -16

 

those arent great numbers, but it's an older engine and im not too concerned, runs great

 

Glad you figured it out.

I'm not sure where you're located, but a vacuum gauge will read an inch lower per 1000' above sea level.





eH.