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Untangling the spaghetti and removing unnecessaries...

47K views 164 replies 41 participants last post by  Will5431 
#1 · (Edited)
Ok gang. I decided to start a thread about what's needed, not needed, what can get pitched and what must stay as far as the vacuum spaghetti goes under the hood. The guinea pig is my 87 DX. All you Si guys, I'm not sure how much of this will apply to you. But I'm sure it'll at least help. Anyways, I'll update this as often as possible to keep you guys informed of my progress with the spaghetti removal.....

And remember, I'm not responsible for anyone screwin up their car by following what I did. And smog-test takers, you guys will probably just have to wonder how much this might help your car instead of actually doing it... LOL ;)

All vacuum line numbers I refer to are how they are numbered from the factory (or at least as far as I know...all my line numbers correspond with the manuals I've seen anyways...).

First thing I did was ditch the EGR. Emissions crap. Unplug lines #4 and #5 coming from the black box of death (right side of engine bay on firewall) where they meet the metal lines on the engine. Plug off the metal lines. You can also open up the black box and remove the vacuum switches/solenoids that those lines went to, or just cut off the rubber lines where they go into the box. Then you can leave the EGR valve there if you want, or you can make a block-off plate to tidy it up a bit. Also you can remove the EGR tube going to (coming from) the exhaust manifold to the intake. A plug will have to be made for the exhaust manifold, and if you do the block-off plate you may need a plug made for the intake side as well.
6/1/08 -- I did some removal of goods in the black box of death. If you crack open the box you will find a myriad of vacuum switches, check valves, an air filter, etc. etc. At the bottom inside the box is a large aluminum double valve. That's for the EGR and can be taken out of the box and tossed. At this point you can also get rid of the vacuum switches and air filter that are connected to the aluminum valve assembly. Two of the vacuum switches have a single wire going to them. Chop the wire on each of the switches and yank them out. Then you can reassemble the box and reinstall.
Stuff from the black box...



Now, see the black box next to the upper timing cover? And the big hose going from it to the black box sitting on the intake? Get rid of all of it. Both black boxes and the associated large tubes. I kept the tube that runs from the box at the timing cover to the air cleaner assembly and plugged it off. The smaller lines just trim back and plug however you see fit that appeals to your eyes. The aluminum piece connected to the second black box (the one on the intake manifold) I haven't taken off yet so I don't know if there's any holes to plug from taking that piece off. But the large tube from that piece to the exhaust manifold can be removed also and both ends plugged. A plug at the intake-side of that tube may not be necessary, I'm not sure yet since I haven't taken that tube off as of yet.
6/1/08 -- You can also remove the white vacuum switch by the left side of the air cleaner assembly and plug the line going to the metal vacuum lines and also plug the other large line going to the air cleaner. Since the two air chamber boxes (the one on the intake and the one next to the upper timing cover) are gone, that vacuum switch is not needed either.
Stuff from the 2 black boxes on intake and next to timing cover...


Another thing you can toss in the garbage is the Anti-Afterburn Valve. Unplug the vacuum line from the AAB Valve to the metal vacuum line and plug the metal line. Then trim back the smaller lines, plug them off and toss the valve. Not needed for function of the carburetors. All it does is hold the throttle partially open when shifting.

I'll add more to this as I do them. I'll also try to get some pics posted so you guys can see exactly what I'm talking about and where. I'm only putting in the removal of stuff that doesn't adversely affect the performance/driveability of my own car. If it makes my car run like dog$&%t, then I hook it back up and consider it a needful thing to have on there... ;)

6/1/08 -- Control box #2 located on the left strut tower...yank it off and throw it and the vacuum canisters connected to it (one below the power steering reservoir, the other is under the left headlight). Then you can plug off the lines at the metal end. You can also get rid of the little orange vacuum switch connected to it lower down on the strut tower. There's another vacuum switch with three vacuum lines on top of the strut tower. That one needs to stay, but the one vacuum line can be redone so it's just a single line--not split off to elsewhere.
Control box #2 and attatched stuff...


The vacuum line that needed to be redone...


The only good use for Autolite plugs per my past experiences...
 
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#162 ·
ok so I pulled everything off and routed my vacuum lines but I did not install the metal airfilter plate (that the filter attaches to) didn't know if it being off would affect the way it ran. the only way I can get it to start is if spray carb cleaner in the carbs. itll fire right up and run until the carb cleaner is gone then it dies again.

my question is do I need to install that metal plate since it does have some solenoids on it (that I'm pretty sure are important for the carbs to operate lol)

thanks guys
 
#164 ·
ya I'm pretty sure I found what was causing most of my issues. 1) I didn't let the carbs build up enough fuel pressure and 2) when I rebuilt the carbs I left a small o-ring off the float bowl which was causing fuel to run out from the bottom of the carbs.

also there are 3 vacuum ports on float bowl cover on the drivers carb and 2 vacuum ports on the float bowl cover on the passenger carb when I read through this not that long ago I don't recall where they were routed to. I tied them 3 of the 5 together and plugged them to straight vacuum and the other 2 are just running to straight vacuum will that work? I havnt had a chance to hook the carbs back up yet so idk if it will run/start lol

just trying to eliminate all the emissions shit and make the thing run right lol
 
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