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Air Intake Strange Mess


Matthew
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Hi all!

Im new here...

Can anybody take a look and tell is it me, or is there something really wrong with those "vacuum loops"?

It is standard 2.0 CIH, it runs very fine, but not perfect.

It seems to me like too much tubes and parts stuffed in?

hope the pics work

https://picasaweb.google.com/115871118239217365162/Cih#5577532252232887074

https://picasaweb.google.com/115871118239217365162/Cih#5577532653060374626

cheers!

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Thank you for replies!

It's left hand drive.

No air con.

f econ -I meant that pipe goes to fuel economy meter on dashboard (if i'm right)

I did an engine swap few years ago for the same engine so the bits of injection might got mixed up.

Don't know which intake manifold is original to the engine, but the one I keep as spare doesn't have additional third hole on the side of that cube like thing.

I remember trying to unscrew `the cube thing` out of intake manifold, but was unable to...

Better MPG device, not sure, it says Bosch 0 280 160 114 and looks old, also the thing it connects to looks original.

John, pic is great, You wouldn't believe how hard it is to find a decent photo of original manta engine, also the one from the side would be perfect if u got one, so I could see

how fuel pressure regulator is connected to everything else.

So I guess I'll try to pull out those `extra` and see what happens, still I'm baffled how it ended up that way anywayunsure.gif

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I just read this on some site:

"The vacuum limiter (or decel valve) is used to burp air past the throttle when decelerating with the throttle closed. It's a hold-over from the K-Jet system.

The idea is to help burn gas which has been injected but unburned because there is not enough air after the throttle is suddenly closed. This unburned gas leads to increased hydrocarbon emissions.

This problem is more pronounced on the manual cars, but for some reason the valve was included on the auto and manual 928's pre-83; 83 and 84 have them only on manuals.

I removed mine. After I removed a bunch of stuff and my vacuum was stronger, this unit cycled at idle, up and down, up and down."

This might be my problem also, tomorrow it goes out! biggrin.gif

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I think i can solve some parts of this little mystery. :)

The "cube thing" was a item used on Manta B cars from 83/84 to end of production. The dashboard changed layout and as you have guessed yourself the eco-meter in the dash is actually just a vaacum meter, and is connected on the cube thing. I always have the "old" dash in my Manta B´s with oil pressure gauge instead.

There is actually only one vaacum controlled item that needs to be mounted on that engine, and thats the fuel shut off valve that is vaacum controlled. Thats the only important thing.

By the way, your engine will gain a little power if you disconnect those water hoses from the throttle body, it only heats up the intake air, wich is not a good thing :)

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I always wondered why is it so greasy inside...

so everybody should do that, spread the wordthumbsup.gif

I wasn't clear, heating it will make it less likely to clog.

Heating it takes:

At least 4 machining operations to throttle body, 2 to thermostat housing.

2 extra pieces of hose

6 hose clips

4 extra fittings.

Companies don't spend money doing that for no reason as it cuts profits.

Probably keeps the oil in breather heated, easier to burn and helps hydrocarbons too.

But short term, yeah you will get a denser charge and a little more power.

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I have never seen one that wasnt cloggy, so those water hoses are just a pure dumsky trick from GM´s side. It clogs up your combustion chamber, spark plugs, valves etc when feeding the engine with oil steam...

And thats another thing. You should remove that breather hose from the engine to the injection. You would do well installing one of theese little buggars wink.gif

k%20and%20n%20breather%20filter.jpg

Its an oil breather filter, and that should sort out both cloggy throttle body, spark plugs etc. And you will then be able to remove those water hoses from the throttle body with no side effects what so ever ! Other than a healthier engine thumbsup.gif

Edited by monzta
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From taking off the water pipes, what would you block off the metal unions on the throttle body with? I'd like to do this to my GTE but I like the engine bay to look good and having open bits wont look right. Most OE inlet manifolds or metal air intake are heated by the coolant runnning through, yet install twin carbs or other after market stuff most of this because redundant.

As for the breather, you could put an oil catch tank between the rocker cover breather and the little pipe on the throttle/air intake. That should stop the messy recirculation and keep the pressure relief. Those little filter adaptors are good but they can block up quickly and also you need to bung up the little pipe that will suck air in behind the filter.

Edited by Rick-Manta
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From taking off the water pipes, what would you block off the metal unions on the throttle body with? I'd like to do this to my GTE but I like the engine bay to look good and having open bits wont look right. Most OE inlet manifolds or metal air intake are heated by the coolant runnning through, yet install twin carbs or other after market stuff most of this because redundant.

As for the breather, you could put an oil catch tank between the rocker cover breather and the little pipe on the throttle/air intake. That should stop the messy recirculation and keep the pressure relief. Those little filter adaptors are good but they can block up quickly and also you need to bung up the little pipe that will suck air in behind the filter.

Yep a catch tank to separate sludge from vapour is the way to go.

UK car manufacurers have to used a closed cranc case ventilation system but it is not prohibited to modify yours to this.

Another thing often neglected is it should be retuned if doing this but I wouldn't. Oh yeah and then you have a blatantly modded engine if the insurance lift the bonnet after an accident.

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From taking off the water pipes, what would you block off the metal unions on the throttle body with? I'd like to do this to my GTE but I like the engine bay to look good and having open bits wont look right. Most OE inlet manifolds or metal air intake are heated by the coolant runnning through, yet install twin carbs or other after market stuff most of this because redundant.

As for the breather, you could put an oil catch tank between the rocker cover breather and the little pipe on the throttle/air intake. That should stop the messy recirculation and keep the pressure relief. Those little filter adaptors are good but they can block up quickly and also you need to bung up the little pipe that will suck air in behind the filter.

The oil catch tank is the best choice by far, but the breather filter version is quite cheap and would do well for a start. An oil catch tank can be made at home.

Regarding those metal unions when removing the water heating to the throttle body its really your choice what to do. I ran a 2,2 head with a shortened 3,0E inlet manifold and throtle body, and on this item i cut away the unions so nothing could be seen. After that i had the entire lump powder coated (looked absolutely stunning), thumbsup.gif

I think that removing them is the best option, but it really is your choice smile.gif

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As per MantaDoc

I would not disconnect the hot water hoses to the throttle, if you want to gain performance then there are proper routes to take, the amount of time that air will spend in the throttle area getting warm from the water heating to the throttle is so minimal that I would guarantee you there is no performance benefit from removing the water pipes.

The high heat conductivity of an aluminium inlet manifold bolted to a hot engine dictates that the inlet area will be warm regardless.

Little filter breather things......

Absolute waste of time in my opinion, I've always removed the gunked up tarred up mesh from the top of the rocker cover to allow the crankase fumes to breath through a lot easier, always had a bit of oil coming through, but nowhere near as much as when the mesh was in place, as it seems to hold the oil and then the crankase pressure just blows it down the hose to the throttle.

Allowing the crankase fumes to be burned actually allows for a slightly richer mixture, rather than getting smells from an ineficient little boy racer filter to circulate out of the engine bay.

Catch tanks are a good idea if engine IS breathing heavy, but unforunately most cheap items like the shiny ally ones that Ebay is flooded with do not do a good job of "catching". The inlet to the catch tank should have a baffle in front of it internally and the outlet pipe should not be right next to the inlet unless internally the inlet travels away from the outlet.

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My GTE has only done 17k and yet when I remove the black AFM to throttle body pipe thing, the oil build up actually runs out it's that bad. I will be putting in a catch tank to the left hand side of the rad (facing the engine from front) as that's an ideal place given that I've got an Opel GT rocker which has size vents and where the throttle body is. So thanks for pointing out about the cheaper ebay type ones. I'm not so sure on that having heavy fumes going back into the air intake is a good thing and I guess those little filter things would block up on me in no time with the thick oil deposit. Technically the car will be burning oil which isn't going to help the HC readings come MOT time and I especially don't want the tester fiddling with my settings to get the emissions down.

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