[Jimbro727]

Hey! I put on a Holley Street Avenger 670CFM the other day, and figured out what mostly everything in my engine bay is (bear with me, I'm sort of new).. but I'm still stumped by a few things on my intake manifold. I'm currently working out a good deal on a new Edelbrock intake manifold, because I believe there are some severe vac leaks, and instead of taking the manifold off and looking it all over, I'd rather just replace it while it's out, hopefully fix the problems, and take the performance increase

I took a bunch of pics, in hopes of catching all of the angles, to make it easier for you all to identify everything:

First off we have this thing here.. before I took the QJet off, it was hooked up to the carb, to the upper left of the fuel line if you're facing the front of the car. I'm not sure where to hook this up, currently it's on Full Manifold Vac next to the PCV port on the front of the Holley, but I'm not sure if this is correct.




This next pic is of the above thing, and a hose that runs from something beneath the intake manifold to a port on the intake manifold (this is to the left of the thing in the previous pics)


Next up is a metal line that I believe runs to the transmission, then goes into a rubber vac line that used to be hooked up to a port towards the bottom left of the QJet (if you're facing the car). I read on the web that this has to do with upshifting the auto tranny.. just wanted to confirm that (or tell me that's totally wrong).. also I'm not sure where to hook this up, I currently have it on the vac T that goes to the other accesories (power brakes, etc.)



Then there's this thing which was never hooked up to anything, and I wasn't even going to bring up, until I noticed it said "EGR" and "CARB" so I started thinking it was supposed to be hooked up to something.


Lastly there's this UFO shaped thing, which I was told is the EGR valve, so I just wanted to confirm that (or not!). It used to have a place on the QJet, but I was told I could just plug it, so when I installed the Holley, I did just that.


And that's it! Here's a few pics of the engine bay, incase it's hard for youg guys to figure out what anything is from the close-ups, this should give you a better idea of where everything is positioned overall.




Sorry for all of the pics, but I just want to make sure I understand everything before I start taking things apart! Thanks guys!

--Jimmy

[Doug Christie]

Originally Posted by Jimbro727

Hey! I put on a Holley Street Avenger 670CFM the other day, and figured out what mostly everything in my engine bay is (bear with me, I'm sort of new).. but I'm still stumped by a few things on my intake manifold. I'm currently working out a good deal on a new Edelbrock intake manifold, because I believe there are some severe vac leaks, and instead of taking the manifold off and looking it all over, I'd rather just replace it while it's out, hopefully fix the problems, and take the performance increase

I took a bunch of pics, in hopes of catching all of the angles, to make it easier for you all to identify everything:

First off we have this thing here.. before I took the QJet off, it was hooked up to the carb, to the upper left of the fuel line if you're facing the front of the car. I'm not sure where to hook this up, currently it's on Full Manifold Vac next to the PCV port on the front of the Holley, but I'm not sure if this is correct.




This next pic is of the above thing, and a hose that runs from something beneath the intake manifold to a port on the intake manifold (this is to the left of the thing in the previous pics)


Next up is a metal line that I believe runs to the transmission, then goes into a rubber vac line that used to be hooked up to a port towards the bottom left of the QJet (if you're facing the car). I read on the web that this has to do with upshifting the auto tranny.. just wanted to confirm that (or tell me that's totally wrong).. also I'm not sure where to hook this up, I currently have it on the vac T that goes to the other accesories (power brakes, etc.)



Then there's this thing which was never hooked up to anything, and I wasn't even going to bring up, until I noticed it said "EGR" and "CARB" so I started thinking it was supposed to be hooked up to something.


Lastly there's this UFO shaped thing, which I was told is the EGR valve, so I just wanted to confirm that (or not!). It used to have a place on the QJet, but I was told I could just plug it, so when I installed the Holley, I did just that.


And that's it! Here's a few pics of the engine bay, incase it's hard for youg guys to figure out what anything is from the close-ups, this should give you a better idea of where everything is positioned overall.




Sorry for all of the pics, but I just want to make sure I understand everything before I start taking things apart! Thanks guys!

--Jimmy

First Pic. No problem you can just block it off completely at the carb cuz it's doing squat now anyway.
Second Pic. If I'm reading it right, your talking about your PCV valve. Looks good to go.
Third Pic. That is the vacuum line to your modulator and does regulate trans shifting.
Forth pic. Not anything that is needed unless you have your EGR system hooked up, which you don't.
Fifth Pic. As stated, that is your EGR valve.

Everything is as it should be.

[Jimbro727]

Awesome! The new intake doesn't have any provisions for an EGR, so it'll be gone all together soon..

I'll plug the thing in the first pic, but what is it and what was it's purpose (just out of curiosity.. the new manifold doesn't have one I noticed)

The PCV valve: I heard that a clogged valve can cause a rough idle, and a slew of other problems.. how can I check this (I guess with the manifold on or off, since I'm changing it anyway).. also.. according to the manual that came with the Holley, there's a place to hook up a PCV valve.. should that be hooked up there? Or is its current location on the manifold alright?

So is the vac line to the modulator in a good place now? Or should it be hooked up to the full manifold vac line on the carb? Or what?

Thank you so much for the response! I figured someone knowledgeable would come along and just clear it all up!

--Jimmy

[Doug Christie]

Originally Posted by Jimbro727

Awesome! The new intake doesn't have any provisions for an EGR, so it'll be gone all together soon..

I'll plug the thing in the first pic, but what is it and what was it's purpose (just out of curiosity.. the new manifold doesn't have one I noticed)

The PCV valve: I heard that a clogged valve can cause a rough idle, and a slew of other problems.. how can I check this (I guess with the manifold on or off, since I'm changing it anyway).. also.. according to the manual that came with the Holley, there's a place to hook up a PCV valve.. should that be hooked up there? Or is its current location on the manifold alright?

So is the vac line to the modulator in a good place now? Or should it be hooked up to the full manifold vac line on the carb? Or what?

Thank you so much for the response! I figured someone knowledgeable would come along and just clear it all up!

--Jimmy

There were many heat activated vacuum switches to control various pollution control devices back in the day. The heat from the manifold or water crossover would activate the switch and allow a vacuum signal to activate another switch at a pre-determined temp.

You can check your PCV valve by pulling it out of the valley pan and shaking it to see if it rattles. Best to just buy a new one if in doubt. As far as hooking it up with the new manifold, it just heeds a large full vacuum port, like the one that my be on the back of your carb.

The line for your modulator should be hooked up tp a full vacuum source like from the back of your carb that feeds the vacuum to your brake booster.
If you have a vacuum guage, you can check the ports on your carb to see if they are ported or full vacuum. The ports that are near the base of the carb are usually full vacuum.

[SergeF]

It will look cleaner. Here is pic of my old motor. Two open holes are for coolant temp and fan sensors

[Jimbro727]

Originally Posted by Doug Christie

There were many heat activated vacuum switches to control various pollution control devices back in the day. The heat from the manifold or water crossover would activate the switch and allow a vacuum signal to activate another switch at a pre-determined temp.

You can check your PCV valve by pulling it out of the valley pan and shaking it to see if it rattles. Best to just buy a new one if in doubt. As far as hooking it up with the new manifold, it just heeds a large full vacuum port, like the one that my be on the back of your carb.

The line for your modulator should be hooked up tp a full vacuum source like from the back of your carb that feeds the vacuum to your brake booster.
If you have a vacuum guage, you can check the ports on your carb to see if they are ported or full vacuum. The ports that are near the base of the carb are usually full vacuum.

OK cool, thanks! I'll definitely check the PCV valve.. and maybe this is a stupid question, but how come mine is in the valley pan instead of on the valve cover like in the pic Serge posted? My Holley has a port that the instructions say is for the PCV, so when I change the manifold should I just hook up the PCV valve to that? It looks like it's the correct size. Also, I looked for a vacuum guage at AutoZone, and all they could show me was a boost/vac guage for inside the car, nothing for a diagnostic purpose.. I looked all around and couldn't find one, where would you guys recommend I find one? Is there a website or store or something?

Oh, and when I change my intake manifold, I heard that it's a good idea to change the valley pan, too.. is this true? I looked around for a valley pan, but couldn't find one, just lots and lots of gaskets, so if you think I should change it, can you recommend somewhere to pick one up?

Thanks again for the responses!

--Jimmy

[Midnight Goat]

Originally Posted by Jimbro727

OK cool, thanks! I'll definitely check the PCV valve.. and maybe this is a stupid question, but how come mine is in the valley pan instead of on the valve cover like in the pic Serge posted?
Thanks again for the responses!

--Jimmy

I think Serge's valley pan is without any opening for the pcv or at least looks that way in the pic. You need vented valve covers if you have a setup like that i think which is why he has it hooked up to the breather. could be way off though ahah.

[Jimbro727]

Originally Posted by Midnight Goat

I think Serge's valley pan is without any opening for the pcv or at least looks that way in the pic. You need vented valve covers if you have a setup like that i think which is why he has it hooked up to the breather. could be way off though ahah.

Oh ok.. i was just wondering what the difference was since I've seen it both ways.. and based on what it does, it seems to make more sense for it to be where it is on mine and not the valve cover.. but what do i know? maybe a PCV expert can clear it up ahah

also.. I finally found a vac guage via a google search at http://www.joewoodworker.com/catalog...products_id=53 -- looks exactly like what I need.. right?

Thanks again!
--Jimmy

[jjscerbo]

And I thought that hackers only worked on computers!!

What a mess!

[Jimbro727]

Originally Posted by jjscerbo

And I thought that hackers only worked on computers!!

What a mess!

Nope, we work on cars, too! haha

[Will]

You probably don't want the vac gauge in the link you posted. The 1/4" NPT fitting on it will make it a pain to hook it up to anything. Go to Sears and get one, they have a nice gauge with a simple vacuum hose for connecting to a car.

The two thermal switches that you've pictured can be left off of your new intake completely. They're not doing anything now and aren't needed for anything. Heck, they both have broken off nipples anyway, so are pretty much useless. As you guessed, the one with "EGR" on it is the EGR control switch. The other one is most likely for the TCS (Transmission Controlled Spark) system. Another unnecessary emission device.

No need to get a new valley pan, they don't wear out. Just put a new gasket on yours if it's leaking.

If you go with a standard Edelbrock Performer intake, don't be too surprised if you don't notice any actual performance increase.

[Jimbro727]

Originally Posted by Will

You probably don't want the vac gauge in the link you posted. The 1/4" NPT fitting on it will make it a pain to hook it up to anything. Go to Sears and get one, they have a nice gauge with a simple vacuum hose for connecting to a car.

The two thermal switches that you've pictured can be left off of your new intake completely. They're not doing anything now and aren't needed for anything. Heck, they both have broken off nipples anyway, so are pretty much useless. As you guessed, the one with "EGR" on it is the EGR control switch. The other one is most likely for the TCS (Transmission Controlled Spark) system. Another unnecessary emission device.

No need to get a new valley pan, they don't wear out. Just put a new gasket on yours if it's leaking.

If you go with a standard Edelbrock Performer intake, don't be too surprised if you don't notice any actual performance increase.

OK great, thanks! I was waiting for some input before I bought it.. glad I did! I'll shoot over to sears and grab one.. I was surprised AutoZone didn't have one

Thanks for the other info.. it's nice to know what I'm looking at when I pop the hood With the vac guage I'll be able to find out for sure if my problems are even being caused by a vac leak.. maybe I should start a new thread for this issue.. but it's idling rougly, and erradically.. but I've yet to play with the timing.. I also hear a loud whirring when the engine revvs.. like a sucking sound.. as far as the Edelbrock goes, I was going to grab a brand new one off of eBay for $165 shipped.. figured if I'm going to go through the trouble of taking it off and replacing gaskets, might as well put a brand new one on.. and instead of going with an OEM one, might as well do an Edelbrock Would you recommend a diff. intake? I know there's some higher performance ones.. but I wasn't sure if I should put such a high performance manifold on a strictly street cruiser

Anyway, thanks for the help everyone!

--jimmy