

Vacuum Line Removal
#1
Posted 25 May 2003 - 01:20 PM

#2
Posted 25 May 2003 - 02:39 PM
what exactly is the function of the vac pump, i was eyeing it today. is that for the heat/ac system?
84StarionES
#3
Posted 25 May 2003 - 02:52 PM
On the '88/'89 cars there are 2 other vac lines then coming off of the wastegate actuator going to the 10psi boost solenoid on the aircan. If you get a MBC (manual boost controller) you'll no longer need those, you just run the OVCP vac line to the MBC, then from the MBC to one of the front ports on the wastegate actuator, plug the other front port with a vacuum cap and leave the rear port (closest to the turbo) open to vent (thanks Mike K.).
The vacuum pump is mostly for the vents, vacuum storage canister, and cruise, if you want these things you'll need to keep it


#4
Posted 25 May 2003 - 04:40 PM
Two questions.
1 - Why does the timing retard get connected to the top port numbered 2 when everything is removed, when it was connected from the factory to one of the three ports on the side of the throttle body?
2 - I have tried to leave the charcoal canister connected on my car, although I have removed everything else except the A/C and timing retard. Should I just forget about that and disconnect those lines?
Thanks for that post UL??
#5
Posted 25 May 2003 - 05:22 PM
2. I assume you mean the small canister bolted onto the airbox? It doesn't actually have a vacuum line going to it, it has the Valve Cover Breather/Ventilator line going to it. Many members have removed this (me included), but many keep it because it's a good system in theory. However, when the canister gets old/full it blows oil into the intake stream, bad, bad idea.
If you're talking about the Fuel Vapor Filter where the Purge Valve is, again, many remove it, some leave it. If you can put up with a slight gas smell from time to time (outside), and you're not gonna' be smokin' right beside it...lol, then yeah, ditch it. I'll get arguments on this one, so just use your best judgement.

#6
Posted 25 May 2003 - 06:05 PM
Keep the vacuum lines running to the purge control valve.




#7
Posted 25 May 2003 - 06:20 PM
#8
Posted 25 May 2003 - 06:34 PM
Two questions.
1 - Why does the timing retard get connected to the top port numbered 2 when everything is removed, when it was connected from the factory to one of the three ports on the side of the throttle body?
I was a confused for a bit until I went back and re-read the RACING ONLY. When racing only the retard function of the diaphram is necessary however the same diaphram on a street car needs to also have a vacuum signal to increase the timing for good part throttle response and gas mileage so it would need to be tapped into a source that can supply both vacuum and boost as needed. There is no vacuum above the throttle plate. I know you were clear UL but this may help Southern Boy and others that may be slow like me! Mark
#9
Posted 25 May 2003 - 07:36 PM
In the picture below you will see the Vaccume Assembly. Unless you have to have a smog test to pass your state inspection most of these vac lines can go (along with their smog brethren parts) and your engine bay will look a lot neater.
The Secondary air-cleaner assembly (big black box on top of the VC) has to stay unless you have gutted both cats. The EGR (thing under the TB that looks like a flying saucer) has to stay unless you make an EGR cap-off plate for it.
When you are done there should be 1 line running from under the 3 ports on the TB (not shown) all the way around the firewall to the cruise control actuator and to the front of the car where the vac pump is located, leave that one. There should also be 1 line running from the top of the TB where the intake tube meets it, to the vac advance (looks like a flying saucer on top of the distributor), this is represented in red. The blue dots mean cap it off and kill the excess line. If you have or are getting a BOV you will need to hook it to the 3rd port on the TB, show in yellow.

B-71 87 TSI ~ RIP
Black 87 Starion ~ Mess SOLD!!!
Proud New 89 slightly Rusted Fiji Owner !!!
#10
Posted 25 May 2003 - 07:51 PM
#11
Posted 25 May 2003 - 08:40 PM
Mark: Why ask why? ;D Trust me, it works, if you're not the trusting sort then just pick another nipple...lol.

#12
Posted 25 May 2003 - 08:55 PM
#13
Posted 26 May 2003 - 09:05 AM
The vacuum reference is ported for the VA. If you look at the TB the first port has a very small 1/16th hole that is above the throttle plate.
The first port does not see vaccum until a certain rpm range. Take the line off at idle and you should have NO vacuum source from it. Give it a little gas and you'll start getting a little vacuum from the 1st port.
If the VA sees too much vacuum it will advance the timing at idle. So if there is a strong vacuum pull at idle you can bet your timing is getting advanced. If you notice the shop manual does not indicate the VA needs to be plugged to set base timing. This is because at idle there should be no vacuum source from the 1st port to disrupt/advance the base timing.
Mike C taught me this way back in 1996. I bet if you search Ryddlers old archives that post will come up if it goes back that far.
Look at the TB chamber and it shows a lot.


#14
Posted 26 May 2003 - 10:59 AM


#15
Posted 29 June 2003 - 09:11 PM
#16
Posted 05 July 2003 - 03:50 AM
I already have a TD05-12a? turbo, stock conquest exhaust manifold on the way. Apparently the wastegate is set at 11-12lbs boost? (conquest turbo) Correct me if I'm wrong. Now I have a few problems with this setup, first is its carbureted, I've looked into going with a blow through carb system and I know I have to have a 1:1 fuel pressure increase so the floats stay full. But what happens to the vacuum stuff? Most importantly, the vacuum advance on the distributor? If its a turbo engine how is the VA supposed to get a vacuum at all? When its boosting (at high rpm) should the timing be advancing with the mechanical advance or with both? At low RPM before the turbo starts to create boost the VA should be advancing right? I guess what I really need to know is what do I have to do to the vacuum advance on the distributor so I can convert this to a turbo setup? Is there any difference? What do I do about the vacuum accessories that need vacuum at all engine RPM like the a/c? What about those vacuum caps to eliminate those other vacuum lines? under boost wouldn't they pop off? thx for any help <img src="http://www.starquest...IR#>/smile.gif" style="vertical-align:middle" emoid="

#17
Posted 10 July 2003 - 10:36 PM




89 TSi 14G, 2.5"Ex,21lb.Flyw, Sht.Shift, SS Hoses,1G MAS/K&N,
125psi F.Pump, Type-H BOV /H-Pipes, 9" Rears, ST's, KYB's.
2008 Toyota Tundra Crew Cab
2014 Silverado Texas Edition
2016 Escalade Platinum Edition
#18
Posted 19 July 2003 - 02:26 PM
btw, its an 88 tsi
thanks, Jason

'88 Black Starion 5-Speed
#19
Posted 16 August 2003 - 07:04 AM
Steven

#20
Posted 24 December 2003 - 03:15 PM
2004 Honda S2000
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