Where to tee off for a vacuum gauge - Ecotec engine w/ gas

[Fonzie]

I would've thought this question had been asked heaps of times, but forum and Google searches yield nothing.

It's a series II VS, hence an ecotec, with a gas conversion. There's a bottle of "valve lube" (something to do with the lpg drying out valves i believe?) that has a drip system and has a small pipe leading into the intake manifold. Could i tee off this for a mechanical vacuum gauge? If not, where do i put it?

[paulsautoelec]

yes you can as long as it is not on the air cleaner side it has to be on the intake manifold

[Fonzie]

Yeah i know that it has to be attached after the throttle body.
My concern, which i probably should have mentioned earlier, is the 'valve lube' i mentioned. It gets sucked from the bottle (through a drip system) into the intake manifold. I'm thinking, will the 'lube' screw with the vacuum gauge's reading?

[PanthaVS]

theres a vacuum line going into the plemun chamber at the rear, its hard to see unless you take off your plastic engine cover, and look where i described from the side of the car, (looking into the engine bay standing back from the front strut tower and foward of the front door hinge)

It's a small hose, that about, 5cm or more from the plenum, has a one-way valve on it, that looks like a little white inline filter, then from there its a slighter different diameter hose. i have a vacuum gauge tapped in between that one-way valve and the plenum.

If your "drip feed" system is hooked into there... as long as your new tee peice is furtherest off the plenum... it should be right? what im saying is... it should be plenum, then drip feed, then your tee piece, then that white one-way valve.

then, the lube wont get "sucked" into your gauge. as it wont go past your tee-peice.

[Ozzie]

as above ^^ look for the vacume hose and cut it in half, fit the "T" pipe in the middle.

Just be sure that the "T" fitting is nice and tight so theres no leaks.

[Fonzie]

theres a vacuum line going into the plemun chamber at the rear.

I ripped the engine cover off before i posted this thread and had a snoop around, but what's the plenum chamber? Perhaps i don't know it by name. I know what and where the throttle body and intake manifold are... Where is it in relation? Out of curiosity, that one way valve, where does it go? I'm assuming the one way is towards the plenum chamber.

If your "drip feed" system is hooked into there... as long as your new tee peice is furtherest off the plenum... it should be right? what im saying is... it should be plenum, then drip feed, then your tee piece, then that white one-way valve.

The drip feed system is actually tapped straight into the intake manifold, On the headlight side. I'm not sure if there was originally a plugged hole there, as this is the only thing on that line, or the mechanic who did the gas conversion drilled a new hole just for kicks.

It should be plenum, then drip feed, then your tee piece, then that white one-way valve.

Given that the drip feed is on a seperate line entirely, would i be fine just teeing straight off that line for the gauge? I'm thinking the intake manifold is the only thing sucking, not the gauge, so the fluid won't get anywhere near it. Once the negative pressure is built in the tee leading to the gauge, the only open avenue for air (on this line) is through the drip system. But then again, given that it's in a different spot, i could do the same thing you've done and tee off between the plenum and the one way valve.

Also, the gauge is in the mail at the moment and it comes with 'appropriate mounting hardware'. If it doesn't include a t peice, where could i get a hold of one?

[PanthaVS]

I ripped the engine cover off before i posted this thread and had a snoop around, but what's the plenum chamber? Perhaps i don't know it by name. I know what and where the throttle body and intake manifold are... Where is it in relation? Out of curiosity, that one way valve, where does it go? I'm assuming the one way is towards the plenum chamber.

Plenum Chamber = aluminium box between throttle body and intake manifold.
One-way Valve = points towards plenum, so air can ONLY move out of the vacuum system and into the intake.

The drip feed system is actually tapped straight into the intake manifold, On the headlight side. I'm not sure if there was originally a plugged hole there, as this is the only thing on that line, or the mechanic who did the gas conversion drilled a new hole just for kicks.

then the oild can't get into the vacuum system at all.

Given that the drip feed is on a seperate line entirely, would i be fine just teeing straight off that line for the gauge? I'm thinking the intake manifold is the only thing sucking, not the gauge, so the fluid won't get anywhere near it. Once the negative pressure is built in the tee leading to the gauge, the only open avenue for air (on this line) is through the drip system. But then again, given that it's in a different spot, i could do the same thing you've done and tee off between the plenum and the one way valve.

Exactly.

Also, the gauge is in the mail at the moment and it comes with 'appropriate mounting hardware'. If it doesn't include a t peice, where could i get a hold of one?

try "champion parts". they do lots of wonderful auto stuff... look them up.