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Discussion Starter #1
I have two questions about the EGR vacuum regulator (EVR):

1. According to the Haynes manual, to test the solenoid mechanically a vacuum should be applied to the bottom port. This vacuum should hold and no vacuum should be indicated at the top port. I have done this test on 3 separate solenoids (1 old one and 2 brand new ones) and none of them held a vacuum at the bottom port. Has anyone actually done this test successfully? I find it hard to believe that all 3 would be bad (maybe I am doing something wrong).

2. On the electrical connector that supplies the voltage to the solenoid, the ground wire is operated by the computer. Is there a relay in line with this ground wire to open or close the circuit? Is there a solid state relay in the computer that does this? I am trying to figure out how the computer opens/closes this circuit.

Thanks for your help.
 

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2006 Lincoln Navigator
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I have been recently through this scenario. I never was able to successfully pull much of a vacuum on a closed EVR valve when using my handheld vacuum pump/gauge. New or old, same thing. All the reference material I read indicate the EVR is a "controlled" vacuum leak. I left well enough alone once I verified the EVR was being turned on by the PCM at the correct time and I am not getting any error codes.

There is no relay between the PCM and EVR. I never looked too deeply into the circuit, but I assume they are using a simple transistor inside the PCM to complete the circuit to ground. The EVR is modulated on and off depending on the the PCM programming. What issue are you trying to resolve?

Some good reading here at Ford Fuel Injection: EGR Vacuum Regulator (EVR)
 

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Discussion Starter #3
Thanks, I'm glad I'm not the only one who couldn't get much of a vacuum using the hand pump.

I'm just trying to solve some trouble codes that have been giving me some problems. I have pulled 327 (EVP circuit below minimum voltage of 0.2 volts) and 332 (EGR valve opening not detected) from CM, so I went through the Haynes manual testing the EGR system. I thought I had found the problem when the solenoid didn't "pass" that vacuum test (inexperience on my part). I bought a new one only to find that it was faulty (no resistance between the terminals). I tried it anyway and the truck died in about one minute of idling. Sure enough, I pulled the KOEO codes and got 558 (EGR Vacuum Regulator circuit failure).

I'm going to go back and re-check the EVP sensor to make sure it passes the checks (for the 327 code).

I was curious about the ground on the EVR since I wanted to make sure the solenoid was opening at the right time. If the ground is shorted out, then the solenoid is always supplying a vacuum to the EGR. I checked the ground while the key was off and it wasn't shorted. When I checked the voltage between the +12 V and ground terminals on the connector with the key in the run position, I read 12 volts. I would assume that it should be 0 volts if the truck isn't running; shouldn't the computer be telling the solenoid that the vacuum (EGR flow) isn't necessary? Maybe the truck has to actually be running to check the voltage at the connector, I'm not sure.

I'm just trying to hammer out these problems to get the truck running somewhat decent again.
 

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Man of endless projects
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9,339 Posts
sry for stealling your thread but to patriots recommnedation to do the delete which i was about to make a thread about. does it make the engine run noticably cooler after doing the delete? also i would think after doing that, you can take the cooling hoses off the throttle body and let the intake run even cooler, is that correct?
 

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Satyr of the Midwest
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17,734 Posts
My recommendation
Is completely wrong, and illegal. We do not advocate this sort of hillbilly modification on FSB, not to mention the detrimental effect upon mileage and driveability. The EGR and its control system are there for a reason. Do not perform such modifications if you want help from me, or many other FSB members.

Back to the question: the EVR is controlled by the PCM, true. But it's done through pulse width modulation. I forget the exact frequency, but it's pretty low (something on the order of 170Hz or so). This is done with a MOSFET and its supporting cast, so the µC can control the EVR properly.

Having said that, it is very important that you have the proper EVR for your particular vehicle (rather, its PCM), since they are matched to work together. I thought I could get away with a Mustang's EVR at one point, but that was a critical mistake on my part.

The vacuum test can be performed on a running engine. Just hook the vacuum line to the manifold, and your vacuum gauge to the other side, then do your testing as normal. The EVP should be next on your list of items to test, IMO, and make certain the vacuum lines are all good, and that the EGR valve holds vacuum.
 

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2006 Lincoln Navigator
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Thanks, I'm glad I'm not the only one who couldn't get much of a vacuum using the hand pump.

I'm just trying to solve some trouble codes that have been giving me some problems. I have pulled 327 (EVP circuit below minimum voltage of 0.2 volts) and 332 (EGR valve opening not detected) from CM, so I went through the Haynes manual testing the EGR system. I thought I had found the problem when the solenoid didn't "pass" that vacuum test (inexperience on my part). I bought a new one only to find that it was faulty (no resistance between the terminals). I tried it anyway and the truck died in about one minute of idling. Sure enough, I pulled the KOEO codes and got 558 (EGR Vacuum Regulator circuit failure).

I'm going to go back and re-check the EVP sensor to make sure it passes the checks (for the 327 code).

I was curious about the ground on the EVR since I wanted to make sure the solenoid was opening at the right time. If the ground is shorted out, then the solenoid is always supplying a vacuum to the EGR. I checked the ground while the key was off and it wasn't shorted. When I checked the voltage between the +12 V and ground terminals on the connector with the key in the run position, I read 12 volts. I would assume that it should be 0 volts if the truck isn't running; shouldn't the computer be telling the solenoid that the vacuum (EGR flow) isn't necessary? Maybe the truck has to actually be running to check the voltage at the connector, I'm not sure.

I'm just trying to hammer out these problems to get the truck running somewhat decent again.
The EVR is not energized, no return path to ground via the PCM, so you are measuring an open circuit. It's exactly the same concept as measuring across an open fuse; the voltage measured will be the supply voltage because there is no resistance present to create a voltage "drop" across across the component as well as no current path from supply to ground.

You need to use that DVM to measure the EVP output when the engine is off/key on. DTC indicates the signal is below the minimum of 0.2 VDC when the EGR is supposed to be closed. This can be caused by an open or disconnected wire, a faulty EVP sensor or a faulty EGR valve. I suspect a faulty EVP or wiring issue in your example.
 

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The Anti Yam!
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22,674 Posts
I have two questions about the EGR vacuum regulator (EVR):

1. According to the Haynes manual, to test the solenoid mechanically a vacuum should be applied to the bottom port. This vacuum should hold and no vacuum should be indicated at the top port. I have done this test on 3 separate solenoids (1 old one and 2 brand new ones) and none of them held a vacuum at the bottom port. Has anyone actually done this test successfully? I find it hard to believe that all 3 would be bad (maybe I am doing something wrong).

2. On the electrical connector that supplies the voltage to the solenoid, the ground wire is operated by the computer. Is there a relay in line with this ground wire to open or close the circuit? Is there a solid state relay in the computer that does this? I am trying to figure out how the computer opens/closes this circuit.

Thanks for your help.
What is the actual problem or code you are getting?


My recommendation
How do you get it to pass emissions without an EGR?
Or, if you live in a non emission testing area, what is your plan to restore the EGR once testing is required by the Fed?
 

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Is completely wrong, and illegal. We do not advocate this sort of hillbilly modification on FSB, not to mention the detrimental effect upon mileage and driveability. The EGR and its control system are there for a reason. Do not perform such modifications if you want help from me, or many other FSB members.

Back to the question: the EVR is controlled by the PCM, true. But it's done through pulse width modulation. I forget the exact frequency, but it's pretty low (something on the order of 170Hz or so). This is done with a MOSFET and its supporting cast, so the µC can control the EVR properly.

Having said that, it is very important that you have the proper EVR for your particular vehicle (rather, its PCM), since they are matched to work together. I thought I could get away with a Mustang's EVR at one point, but that was a critical mistake on my part.

The vacuum test can be performed on a running engine. Just hook the vacuum line to the manifold, and your vacuum gauge to the other side, then do your testing as normal. The EVP should be next on your list of items to test, IMO, and make certain the vacuum lines are all good, and that the EGR valve holds vacuum.
Actually... The way you responded to this is wrong and you should be ashamed as moderator. That's my .02 as a new member to this site, and my 1st post. Save the dictatorship for those that are responsible for governing and enforcing those laws. This is the internet (and America) where freedom of speech and expression IS LEGAL. Allow people to make there own choices and relax. Talk about making an impression on someone new to the forum...
 

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Due to the direction this thread is going, this program is being briefly interupted.....

To get the drift of WHY we have an EGR valve, ya need to have some background in emissions development as it applies to cylinder head design.
Way back when, enginers discovered that designing a wedge shape into the combustion chamber and placing the spark plug at the wide part of the wedge caused the flame-front of the burning gasses to slow down as it burned across the top of the piston during the beginning of the the power stroke. That in turn allowed for a higher compression ratio and a bit more timing advance WITHOUT detonation (AKA pinging). Such heads are said to have a high amount of "quench". Unfortunently, they also produce a fair amount of unburned fuel particals which was an unacceptable condition as far as emissions goes.....hence the modern day (emissions) heads with their "fast burn", more "open" chambers.
Emissions-type, fast burn heads do a good job of reducing emissions...but....the down side is that unless a lower C/R is used, or if the ignition-timing isn't reduced, they also tend to detonate as engine load and/or RPM increases...hence the EGR valve. What the EGR valve does is introduce the correct amount of exhaust gas into the intake, AND at the correct time, so as to "dilute" the incoming fuel/air mixture which in turn, slows the burn rate enough that "pinging" is eliminated without resorting to a rediculasly low C/R and/or advance curve.

The bottom line to all that is.... Like Sig said... Ya NEED to retain the EGR system on a modern-day vechicle. And it needs to function proper.
If anyone feels the need for further discussion on the pros/cons of removing an EGR valve, my suggestion as a non-moderator is to start your own thread. The OP of this one is merely asking for help in fixing his factory system.

We return you now to your regularly scheduled program.
Thanks for your time.

DGW
 

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The Anti Yam!
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Actually... The way you responded to this is wrong and you should be ashamed as moderator.
When did Sig become a Mod? :doh0715:

No one told me :cry

This is the internet (and America) where freedom of speech and expression IS LEGAL. Allow people to make there own choices and relax. Talk about making an impression on someone new to the forum...
Your new, get to know the site a little. :histerica


Welcome to FSB :thumbup :beer
 

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Actually... The way you responded to this is wrong and you should be ashamed as moderator. That's my .02 as a new member to this site, and my 1st post. Save the dictatorship for those that are responsible for governing and enforcing those laws. This is the internet (and America) where freedom of speech and expression IS LEGAL. Allow people to make there own choices and relax. Talk about making an impression on someone new to the forum...
you forgot to thank SIGEP for the correct info that he took his time & effort to post-up
 

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9,984 Posts
FYI, the EGR solenoid (E4ZE 9D 474 E3A) under the "black air reservoir" nearest to the engine when looking in from the passenger side is "obsolete" and very difficult to find but will be listed on most auto parts websites deemed "currently unavailable", shit out of luck in other words but the other EGR solenoid (E5TE 9D474 AB) closer to the fender is readily available just about any where, Neihoff being a good brand perhaps...

These solenoids where Mfgd by Lectron Roch for Ford in MI.....and are very durable (diaphram inside) with a decent life expectency and not widely prone to failure....I still have both my OEM originals just in case shit happens....lol lol

For a Ford OEM obsolete replacement part I paid around $115.00 shipped from my go to guy for hard to get parts...if you can't find it this guy can.......prices are resaonable...

John Crone ~ owner
Peerless Auto Parts
Torrance, CA
(310) 856-4810


Thanks SigEpBlue...lol lol

Good Luck ~ :thumbup
 

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I dont know about wedge heads and such. But I do know that you can remove the air pump, ERG, cats and all that mess of vacume hoses and the truck runs just fine. It also gets better millage. I would never advocate doing something illegal, but I also dont believe in giving out mis-information. By the way, it is not illegal on an off road truck.

The point is this forum is for information, not political views.
 

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Discussion Starter #15
Thanks for all of the information.

I have already checked the vacuum lines and the EGR valve, both of which are fine. I am going to re-test the EVP sensor/harness to make sure I didn't miss something the first time around (I have a feeling that my problem lies somewhere in the EVP/harness). Since my OEM EVR is still good, I am going to re-install it and go from there.
 

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Discussion Starter #17
From my reply to this thread (third post):

I'm just trying to solve some trouble codes that have been giving me some problems. I have pulled 327 (EVP circuit below minimum voltage of 0.2 volts) and 332 (EGR valve opening not detected) from CM, so I went through the Haynes manual testing the EGR system.
Thanks.
 

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Satyr of the Midwest
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Woohoo, I'm a mod now! :chili:




:histerica


Save the dictatorship for those that are responsible for governing and enforcing those laws. This is the internet (and America) where freedom of speech and expression IS LEGAL.

Uhhh.....contradiction in terms much? You have no clue what you're talking about. :haha Also, you made a lame first post. How's THAT for freedom of speech? :goodfinge


I love how so many Americans think the first amendment applies to "teh intarwebz" and its privately-owned websites.
 

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Lame 1st post huh...??? Get a life. You're a internet nerd that tries to tell people what to do.

LOL. Just checked out your stock rig. No wonder you responded the way you did.
 
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