Here's an easy question for you guys...

[fivestangs]

...I'm putting my '93 Cobra back to stock, and that means returning some of the emission stuff back in place...in this case, the EGR valve...of course...I forgot where it's vacuum source comes from...where do I hook up the vacuum??

A pic or diagram would be nice :shrug:

Thanks!
Mark

 

[buddha93]

I don't have a pic handy, but it comes from that multi-split source between the strut tower and firewall. It's a single unit with 4 lines that come off of it. Here is what your looking for:

86 87-93 MUSTANG VACUUM LINES 5.0: eBay Motors (item 160486567058 end time Oct-27-10 21:13:12 PDT)

You use one of the short 90 degree ones. The other goes to the FP regulator. The long one goes to the back of the intake, and the other runs down to the smog pump hose.

 

[fivestangs]

I thought the FP line came from the tree under the upper intake? (at least, that's how mine is setup now, seems to work fine)

If I remember correctly, it's one of the 2 grey ones (as seen in that e-bay pic), but which one?

edit...I found this on another site:
"There are 2 white vacuum lines in that area: one is for the EGR and the other is for the Thermactor Air System (smog pump) diverter control valve. The rubber coupler in your picture has different line colors on each side. Push the plastic cover over the vacuum lines back so that you can see the line color before the rubber coupler. The EGR line will be green. The smog pump diverter control valve line will be white."

...so, looks like I need the one that ties into the green line.

 

[buddha93]

Ya, I believe that's right. I was thinking there was only one that went to the control valve, but there are a few of them on the hoses.

In any case, it doesn't matter where you get the vacuum source from, but thats what the factory assembly looks like.

 

[fivestangs]

Ya, I believe that's right. I was thinking there was only one that went to the control valve, but there are a few of them on the hoses.

In any case, it doesn't matter where you get the vacuum source from, but thats what the factory assembly looks like.

Actually, it does matter where it comes from...the vacuum source for the egr is controlled by a solenoid connected to the eec-iv...hooking it up to just any vacuum source is sure to throw a check-engine light when the computer commands the egr to open and the egr sensor doesn't respond... my problem was that I wasn't sure which one of the 4 hoses was the right one...but now that I know it's the green one (and what the egr control solenoid looks like), I can hook it back up correctly :beer:

Thanks!
Mark

 

[buddha93]

You sure? The reason I ask as I've seen plenty of cars using any vacuum source, as well as no vacuum line attached with no MIL errors.

The EEC does control the EGR, but it uses the needle position of the EGR, as well as the EVR and PFE to make adjustments which all share a common vacuum source.

Dunno, I'm far from an expert and only know what I've worked on and picked up with tech books.

 

[fivestangs]

LOL..I'm no expert either...I thought the way it worked was as simple as:
* computer decides it needs to open the egr valve
* computer commands the EVR (EGR Vacuum Regulator) to open by grounding the solenoid
* solenoid opens, thereby allowing vacuum to reach EGR valve
* EVP (EGR valve position) sensor should detect that the valve responded...if not, it's supposed to throw a code

Like I said...that's how *I* interpolate what I've read...which is why I think you have to ensure the vacuum line (the green one) from the EVR solenoid is the one the EGR is connected to.

But I could be wrong??!?! ....I'm not above eating humble-pie when it's due.

Anyways, I'm going to hook mine up that way...I'm sure it'll be fine...and if it starts throwing codes, I'll just disable it via the tweecer

Mark

 

[fivestangs]

By the way..this would be easier if somebody on here who has a bone-stock original Cobra would just go take a look and report back here...

 

[buddha93]

By the way..this would be easier if somebody on here who has a bone-stock original Cobra would just go take a look and report back here...

No, it's sounds like you've put more thought into that me. Besides, what your saying makes sense. I'll walk out and take a look at mine and see what it looks like.......I'm curious now.:rolling:

 

[TEAL VNM]

My car is not stock but this is what mine looks like. Hope this helps.

 

[buddha93]

Like I said...that's how *I* interpolate what I've read...which is why I think you have to ensure the vacuum line (the green one) from the EVR solenoid is the one the EGR is connected to.

Mark

Nope, you got it dead on Mark. Green is indeed the feed for the EGR. The red is the line fed from the back of the intake, the black feeds the solenoid closest to the smog pump, and the white feeds the remaining solenoid. Hope that helps.

Like I said, I never put much thought into the system, but good info. Eating my humble pie as we speak........;-)

 

[fivestangs]

My car is not stock but this is what mine looks like. Hope this helps.

Thanks for the pic...that helps a lot!

Mark

 

[fivestangs]

Nope, you got it dead on Mark. Green is indeed the feed for the EGR. The red is the line fed from the back of the intake, the black feeds the solenoid closest to the smog pump, and the white feeds the remaining solenoid. Hope that helps.

Like I said, I never put much thought into the system, but good info. Eating my humble pie as we speak........;-)

Hey, my junk isn't ever going to be showroom-new original, but I would at least like to get the simple/easy stuff done correctly

...and feel free to send some of that pie my way, I love pie! :banana:

 

[SpikeDD]

Good thread and info guys. I've run my GT without the EGR line connected and never threw a light. It will give a hard code " low flow EGR " and in my experience, also may give the same code WITH the EGR hooked up. Apparently, through some tech friends at Ford, is quite common and since it doesn't throw a light, they just let it slide.

 

[buddha93]

Good thread and info guys. I've run my GT without the EGR line connected and never threw a light. It will give a hard code " low flow EGR " and in my experience, also may give the same code WITH the EGR hooked up. Apparently, through some tech friends at Ford, is quite common and since it doesn't throw a light, they just let it slide.

I can only add that if you don't run the vacuum line, I've always read to keep it plugged into the harness so it the EEC can track the pintle position of the EGR. It's a timing thing.