HAI-TEK7

iTrader: (31)

does it matter what line goes to what rotor?? or they both get oil at all times?

z4csl428

each will only go to a certain housing, lay them out and they'll tell you where they go....

rynberg

DaleClark

iTrader: (55)

The lines will only fit one way, but it doesn't matter which goes to which rotor. They both get the same amount of oil pumped to the injector - the rotor coming by on the intake stroke is what sucks the oil out of the injector.

Dale

DamonB

Actually not. The oil comes out of the injector because the OMP pumps it out. An FD is turbocharged and when under boost the entire intake tract from compressor to rotor face is under pressure, there is no vacuum present to "suck" anything except at the air inlet. The OMP literally pumps the oil into the engine.

How FD OMP works

DaleClark

iTrader: (55)

I'm not 100% certain of the mechanism, but the OMP does also function with a pressure differential of some sort. There's a check valve built into it, and you have differing pressures at the injector due to the vacuum line going to the top of the OMP.

Anyhow, thanks for the clarification - I was just trying to give a layman's idea to show that *when* the oil is injected is mechanical, not like a fuel injector that needs to spray at the proper rotor position, thereby alleviating the worry of reversing the lines.

Dale

rynberg

I just learned this week about the check valve function of the oil injector nozzles (thanks Rick). The check valve is necessary to prevent boost from blowing oil right back down the vacuum lines leading to the turbos. I wonder how many people have thought their turbos were bad and blowing oil when their oil nozzles had failed instead....

HAI-TEK7

iTrader: (31)

I have aftermarket stainless lines, and i cant find the stockies to lay them out.
So i guess it doesnt matter which way they go

thanks

Rynberg: I meant was, if each rotor was fed the same amount at all times or going back and forth from front to back. my bad for the confusion

katit

iTrader: (1)

Old post, but I'm curious.

Where those vacuum lines go? I have BOTH vacuum lines completely swallen with oil and blown from OMP nozzles. Then oil leaked down the block.

If there is no vacuum/pressure on those lines what's their function?

Thanks!

Mahjik

iTrader: (1)

Primary turbo intake elbow. There are two nozzles there, one for both OMP oil injectors, the other a vent line for the oil system.

katit

iTrader: (1)

Hm. So, those pipes have vacuum then. They basically suck oil into turbo. How did it happen that they got blown off the nipples? Is there any pressure there?

KaiFD3S

iTrader: (37)

Another question, when re-installing the lines. Is it necessary to have the lines in front of the waterpump housing or can it be placed behind it? I just think it would be easier to take the Water pump housing off without the lines in front of it.

afterburn27

iTrader: (5)

The primary turbo intake elbow shouldn't see vacuum or pressure. Well... there might be a slight vacuum, especially if the turbo is sucking air through a clogged airfilter. But I always assumed that they just used that location to source filtered air.

katit

iTrader: (1)

Source air? Why do they need to source air? I understand it that vacuum hoses on oil injectors is nothing but a solution to collect spit out oil (which shouldn't be spit out)

Since intake sucking air - there is enough to draw that oil into turbo.

I took turbos to rebuilder and also my primary turbo a little weak - he said that there is no way it was pushing oil. So, all oil came from OMP injectors into intake. And I got plenty of it...

afterburn27

iTrader: (5)

It sounds like the check valves in your oil injectors are bad and allowing oil to push through the vacuum lines under boost.

katit

iTrader: (1)

I still wonder what is the deal with vacuum lines on injectors. What it's function?

Mahjik

iTrader: (1)

It's a vacuum source to keep the nozzle valves closed when they aren't needed (i.e. like at engine shut down time). Many single turbo guys eliminate the oil injection vacuum source. However, if you have the means to connect it, you should.

BigIslandSevens

iTrader: (4)

As to your other post about the lines being filled with oil... your injectors check valves have failed and you need to replace them. Do them both since you will be that far in anyways. Mine did this exact thing about 4 months ago. I also experienced fouled plugs every 4k miles. As well when the injectors REALLY failed completely( just started dumping oil into the intake under boost. Because the check valves were bad ), the ignition would break up when any boost was added. All the symptoms I had when they failed. I have a single turbo but the theory is exactly the same.

afterburn27

iTrader: (5)

Do you have any documentation to back that up? I expected at least one link in your post!

The only time there should be a decent vacuum in the intake elbow is under boost when the turbo is really pulling air through the intake, increasing the velocity and fighting the filter. But remember that when the turbos are creating positive pressure in the manifolds and intake chamber, the check valve in the oil injector is going to be closed. No air is going to flow from the injector to the intake.

When the engine is pulling vacuum the check valve is open and needs to draw in filtered air, which is why I think Mazda used the primary intake elbow.

I don't have any documentation either, so this is all speculation on my part.

Here is something else to think about: what do the 2nd gen NA guys do? I'm pretty sure the oil injectors draw air from BEFORE the throttle body plates. Yep... no vacuum for them.

mono4lamar

iTrader: (32)

I'm lost as to what questions are still up in the air.... Soooo

1) Take each valve out of the block and blow through them. Now try to suck air back in or rotate it around and try to blow through. They are to only work one way. If they are letting air backwards they will be sucking in oil to your turbo/turbos.

2) the location of each line to the correct rotor housing is... The bottom port on the OMP goes to the front rotor housing. The top port goes to the rear rotor housing. They should be wrapped behind and around the water pump housing.

This should be all of the questions for this thread. LMK if there's any other questions or confusion.

katit

iTrader: (1)

Bingo. Good thing I didn't drive for long time like that. Intake was filled with oil and vacuum hoses connected to nozzles completely swallen and let oil go to the block and down making mess. Lookslike pan leaking near motor mounts but I tracked it all way up.

I took nozzles out 10 minutes ago and sure thing front rotor one blows opposite way. It seem to be "working" allowing to suck air out but not blow in. Just opposite of what needed.

Hopefully all that extra oil in intake were enough to lubricate front rotor.

I'm in more stuff since I'm there anyway... I think I will DIY meter lines, they like $60 new.

Mahjik

iTrader: (1)

Didn't think I needed it. However, there are lots of posts on these especially in the Single Turbo section.

There is constant vacuum. Doesn't necessarily have to be much, just put your hand over the primary turbo inlet.

Basically, there seems to be a consenses of several ideas/functions:

1. To help meter the oil being sucked in. Without vacuum pulling in the opposite direction, the engine under vacuum would consume more oil as it would be "sucking" the oil through the lines. Thus rendering the metering sort of pointless.

2. To help ensure the oil injection lines are not empty when the valve closes (so the OMP doesn't have to fill the lines complete again to supply more oil).

Many shops cap the oil injectors when doing single turbo upgrades. So whatever the "exact" purpose of them doesn't seem to greatly effect people who remove them.

afterburn27

iTrader: (5)

Sorry, I am not really trying to argue, but rather open a discussion because I am curious. I am in the process of converting to single turbo and trying to decide what to do myself.

I have read most of the threads on this subject, but it all seems to be speculation. I figured you ("Mr. Links" ) might have the best chance of finding any kind of 'official' documentation describing the purpose of these vacuum lines.




1: The vacuum from the intake chamber will be MUCH greater than whatever vacuum there is in the intake elbow.

2: Maybe... not really sure how it would keep the lines full though. I will have to dissect one of the injectors some day.

To be honest right now I think the best thing to do is just cap off the injectors and let the OMP do its job. It doesn't seem like the vacuum line really affects its function. I have clear OMP lines now, so I can make sure the oil is flowing.

Mahjik

iTrader: (1)

You can debate it with Ihor:

https://www.rx7club.com/showpost.php...33&postcount=2

I suppose he's more creditable.

afterburn27

iTrader: (5)

Yes, he is. Thanks for the link.

However, there is still the question of why NA 2nd gens do not apply vacuum to the oil injectors. The injector part number is the same for 2nd and 3rd gens, so no difference there. From a quick search it looks like they draw filtered *atmospheric* air from before the throttle plates.