Couple questions after looking at the LIM and the gasket between it and the engine.

Blue circle: this seems to provide the fuel injectors with air through tiny wholes drilled in middle iron.

Green circle: at first I thought this was completely useless because the gasket blocks this, but then in the new gasket (no carbon to cover it) I noticed a pin hole. what is this for and why are the ports on both side of the gasket huge compared to the small pin hole connecting the two.

Yellow port: can i just cap this off (I'm running single with no emissions)

Red port: what is this used for? doesn't look like I should just cap this one off


THANKS FOR THE HELP.

 

I think you forgot your picture?

 

lol, yes I did. thanks!

 

I had the red, blue, and green weld shut on my LIM.

yellow, I think I left it and will use it for fuel pressure.

 

I have the red and yellow capped.

 

anyone know what each one goes to though? Also the red goes to the injectors, capping this off worries me. and why such a pic port for the green when the gasket only has a pin hole?

 

bump.

here I thought someone would spit out the answer right away and make me the newbie fool for not knowing already

 

The yellow is for a vacuum line to run to the FPR solenoid. Some people bypass the solenoid and hook the line up directly to the FPR

You can see this at http://www.turborx7.com/images/Techn...e_diagram2.jpg , it is the light blue line going from the yellow location in your picture (hidden in the diagram behind the 4 close hoses, it goes towards the oil fill tube in the diagram) to the pass side/turbo side of the FPR solenoid A (Pressure Regulator Control)

I think the red marked nipple is for the yellow pictured hose in the diagram that runs to the ypipe, I am pretty sure that yellow hose is the correct hose that goes to the hose nipple marked red.

When I upgrade my fuel system in a few days I will get a good look at those.

 

you can block off every thing that is on the LIM/ENGINE gasket surface. doing so has no ill effects. . . though, i cant remember what the red port does. . . i dont remember it being anything beneficial to running the car. . . simply emissions whatnot i think. . . though i cant totally remember. blocked it off because its no longer used.

 

why does it go to the injectors though, i thought that was odd. I'm running an aftermarket fuel system and my FPR is getting it's vacuum from the UIM. So I can block off the yellow.

Also what about the blue and green ports? I find these ports very odd. I imagine they are both for some type of emissions control but the way the green one is setup with a pin hole in the gasket is very odd. There was a lot of carbon on the gasket in this area when i removed the old one. So much that I couldn't see the pin hole. This may end up affecting it's function.

 

Blue and green are EGR passageways, I believe. This is how exhaust gas gets to the EGR valve.

Yellow is definitely for the fuel pressure regulator. That's hands-down the best vacuum reference for the FPR as well.

Red is for the fuel injectors. That hose goes to pre-throttle body air. With the throttle body nearly shut (like at idle) you've got near-atmospheric pressure in the intake tract before the throttle body, and vacuum after the throttle body. That hose brings air in to "swirl" around the plastic air bleeds at the primary fuel injectors to help atomize fuel at low RPM/low load. It's a Good Thing - keep that system.

Dale

 

ok, so I'll change my vacuum source for the FPR to the yellow one, but I'm going single so where should the red port be connected to retain the system?

also could it be beneficial to block of the blue and green ports so that exhaust can't get into the LIM (keeping temps down)?

 

That's a good question on where to pull the vacuum source from. I'm not even 100% sure where the stock source is pulled from - might be the primary turbo inlet duct. I saw one guy with a single turbo once with a vacuum source on the turbo's inlet.

Not sure on blocking the EGR passageways. Might want to trace how they are routed and find the best way. I know how the FC passages are done, but I haven't torn into an FD enough to have tested and learned how that system is plumbed.

Dale

 

The red pipe goes to the downward facing nipple on the stock y-pipe. You may already know that but anyway. If your compressor housing has a nipple on it, you could connect it there or if not you could get a checkvalve with a filter and that would work. Don't know where to get that small of a filter though.... Maybe a filter off one of the stock solenoids.

 

yeah it goes to the nipple on the y-pipe, so any source of filtered air that never sees vacuum would suffice right? But the y-pipe does see vacuum so wouldn't the vacuum hurt what this is designed to do? I know I'm not understanding something here. Is air forced into the area by the injectors or is it simply sucked in, like if I left the nipple uncapped it would work correctly? Basically what type of air source does it need to see?

*confusing myself*

 

It seems logical that the air would be forced into the LIM from the ypipe when under boost, not sure when not under boost. I think if you are not running the ypipe, then you would want to connect the hose to somewhere after the turbo but before the throttlebody. Not sure about anything else.

 

By compressor housing, I meant after the compressor. Air is essentially "sucked" into the primary injector area becuase of the pressure difference between atmospheric and vacuum that the engine pulls.

If you just leave it open it would work fine at idle, but you'd have a boost leak when on boost.

 

so basically any source that sees boost and is before the TB. Under boost air is forced into the injector area. Under vacuum their is more vacuum in the engine than the is in the intake tract before the TB?? And therefore air is still forced into the engine? Is this right?

 

is this correct guys? I know I can simply plug it off and be ok, but I'd like to retain the system. If I tee off the line from the compressor housing going to my w/g will this mess up the boost signal my WG sees?

 

The blue port is actually used to port air in conjuction with the ACV. That path can be easily be verified. My 95 does not have the green port nor do 95s have an EGR valve so perhaps Dale is correct about this port.

If you look in the Single Turbo section for vacuum diagram most of this is discussed.

 

Actually it doesn't apear that this has been discussed. I'm familar with the diagrams, i know where things go in a stock setup and non-sequential. I know I CAN just block them off. I'm trying to do this the proper way, it doesn't seem that there is much firm knowledge on this subject.

I just need to know what air source to use for the swirl air around the injectors.

 

I assume you mean the two lines above the injectors. If so, I agree there doesn't seem to be a consensus. I have mine open to atmosphere. I have read where others have them to atmosphere with no problems.

According to the sequential vac diagram, they are hooked up to the intake (filter) side of the turbo. So if you wanted to keep that setup just install a nipple on the intake side of your single setup. Or you could hook it up to the upper intake and use a check valve to prevent boost from hitting the injectors. In the last configuration I am not certain whether the vac at the intake is the same as that at the manifold.

 

My previous response was with respect to the vacuum lines on the engine.

Here is the thread that I was referring to, which discusses the various lines.

https://www.rx7club.com/showthread.p...vacuum+diagram