Replaced all vacuum lines, have questions.

[d0n_3d]

I just recently replaced all my vacuum lines as the completion of my car is very near...but I have a few questions.

First of all, I ran straight vacuum hose to each component (fuel pressure regulator, pcv, capped off the port at the block for egr since i removed it, fuel vapor canister, and boost gauge or map sensor)

I noticed there are check valves that were installed from factory...are those check valves really necessary or can I leave them off?

second question is...where the heck do those two long plastic vacuum lines going to back side of the passenger side fender in front of the ac housing go??? i know one of those lines goes to the heater control valve, the other went to a check valve near the egr solenoid...how do I hook that line up if I took my egr out???

 

[ijames]

You must have the check valves or you will pressurize your a/c controls, among other things. There are three (working from memory here on a Monday morning so go easy if I get this slightly wrong ) metal lines that go across the front of the intake, under the throttle body. One turns up and goes only to the fuel pressure regulator, one points towards the driver's fender and goes to the charcoal cannister, and one turns towards the firewall. This should have a short hose, a check valve, a short hose, and a tee. Then a hose goes from the side arm to the EGR control valve and another hose goes from the straight arm on to a combination check valve/tee right by the firewall. One leg goes to the driver's fender and forward, to the cruise control and vacuum ball. The other leg goes towards the passenger fender and then through the firewall to the a/c controls. If you have removed the EGR, just take out the tee between the check valves and use a straight piece of hose to connect the check valves. There should also be a check valve next to the charcoal cannister. As for the two lines in front of the a/c box, one goes from the heater control valve through the firewall to the a/c controls, and the other goes from the vacuum block on top of the doghouse (second from the back) through the smaller of the two metal tubes welded to each other (the larger is the pcv) to the hard plastic line to the firewall and then across to the map sensor (or pressure switches if a digital dash car) on the passenger firewall.

 

[d0n_3d]

HELP!

Ok here's what I did...looking at the vacuum block on the passenger side from left to right...

vacuum port #1 = pcv line...ran a straight hose from the port to the pcv valve, no check valve

vacuum port #2 = boost gauge/map sensor...ran straight hose from port to a tee, one part of the tee going to my aftermarket boost gauge, the other going straight to the map sensor, no check valve

vacuum port #3 = fuel pressure regulator...ran a straight hose from port to fitting on afpr, no check valve

vacuum port #4 = egr system...just capped off the port on vacuum block, no longer running egr components, have block-off plate and gasket for old egr location on manifold, took off solenoid and vacuum lines (please note there is no cruise control on the car either)

vacuum port #5 = fuel vapor canister line...ran a straight hose from port to canister, running stock check valve inline with the hose, blow-through side facing direction of canister (air can be sucked away from the canister but cannot go back to canister)

also did away with the big vacuum plastic ball that was near the headlight assembly up front...got rid of all those vacuum lines and capped them off at locations where needed...

also hooked up heater control valve with long plastic line coming from fender area on passenger side...the other long plastic vacuum line I have no idea what to do with? should I just plug it up? or connect it somewhere...I think it used to plug in where the check valve was near the cruise control on the other side of the engine compartment...

does this all sound correct? anything I am missing??? I just need to know what to do with that last vacuum line that runs along side the heater control vacuum line...

 

[scottyb]

Stock setup:

Your #4 should go under the TB, check valve, T - one to EGR, other to firewall. At firewall, another check valve, another T (or a check check valve that has 2 ports on the vac only side), one line to cruise unit, other to the passenger side firewall and into HVAC.

Since you've removed the EGR, then make port #4 go to check valve, then T, one to cruise, other to HVAC.

 

[ijames]

I think you have most of it, plus the last thing ScottyB suggested. Only other comment is that Buick did want to use that metal line and short plastic line to the fuel pressure regulator for a reason, to keep the pressure signal as accurate as possible. A hose that long can take some time to swell under boost and delay the fuel pressure rise slightly. Enough to worry about? I don't know, but I would use either the stock metal line setup or some hard plast line with a short hose at each end so I woudn't have to worry about it. Same for the lines to your boost gauge and the map sensor, and if you plan on using that map sensor for an aftermarket ecm I'd run it on its own hardline to keep the volume down as well, and tee the boost sensor in somewhere else. Oh, since you are connecting directly to the vacuum block now, I found a cute tee that had both legs coming out the same side so it looks like an "F" from the side. Put the straight leg on the second port from the rear, and put the map sensor on one of the side arms and your boost gauge on the other - very compact and looks good.

 

[d0n_3d]

thanks for the help guys...sounds likei shouldn't cap off port 4 and just run some line to a check valve and then to a tee and then connect a cruise line and the long ling going to the back of the fender on the passenger side...

will the straight vacuum line hurt anything on the fuel pressure regulator? i thought vacuum was vacuum...the hose is on tight so it won't leak...it's the perfect size...

 

[scottyb]

I agree with Carl. While it's likely to be no problem, I personally wouldn't skimp on the FPR vac line. Remember it's also a boost line. I take it you don't have the original metal lines?

 

[d0n_3d]

Originally posted by scottyb
I agree with Carl. While it's likely to be no problem, I personally wouldn't skimp on the FPR vac line. Remember it's also a boost line. I take it you don't have the original metal lines?

this is correct...for some reason I discarded them...I wanted all new lines...guess maybe I should have stuck with replacement metal lines? oh well it's too late for now...I want to get this car going! so running a straight line from the block to the fpr is no good? the hose isn't that long...heck it's about a foot long that is just looped around the back side of the vacuum block...

 

[ijames]

It's not bad, it's just not the best. Run it that way for now, and maybe later go back with some kind of hard line.