[TNT89Bronco]

I have been reading up on the green vacuum hose purpose under the hood and see that it goes from the EGR Valve to the EVR Solenoid. I see several green hoses under the hood, and none of them look like the pictures I see in other posts on FSB.

It looks like there is a cut green hose next to the firewall of the Bronco, and another cut end on the passenger side, next to the engine block. However, I see what appears to be a full set of green hoses on something resembling the EVR solenoid, but like I said..I am not too sure since it look different from the other pictures in other posts.

Any advice on what you see or what you think I should do to test the system would be appreciated. The Bronco seems to run fine, but like most people, I am getting in the 10mpg or less, and I don't have a heavy foot.

Thank you.

 

[Dustball]

Follow the vacuum diagram on your air filter housing.

 

[TNT89Bronco]

I guess what I should have asked is "Is this stock for an '89."? I just bought this and am trying to figure out if this is a problem or not. There isn't anything on the air filter housing, and like I said...this doesn't look like the pics on other posts.

Thanks for helping.

 

[Seattle FSB]

Here, I took all of my vacuum lines off just to show you how the EVR Solenoid connects at the top right, goes around the back of the engine and then to the EGR. The TAB, TAD and EVR Solenoids have a common vacuum line. Then the other side of each solenoid goes to the Thermactor Air Bypass (TAB), Thermactor Air Diverter (TAD) and EGR respectively.

 

[Seattle FSB]

Does this help? Be advised that the vacuum harness is laying upside down, but you should get the picture.

The vacuum comes from the Intake Manifold Vacuum Tree, to the Vacuum Reservoir (coffee can), then to the Solenoids which direct it to the Valves. My Vacuum Reservoir lines at the Solenoids change from black to white to indicate vacuum. Yours are green which can be confusing.

In other words, the bottom solenoid lines are all inner connected to the Vacuum Reservoir. The top lines operate the Emissions Valves.

 

[TNT89Bronco]

Ok everyone. I think I finally have it figured out.... It took a little while, and thankfully, I have a "donor" Bronco sitting in my parking lot to help me out. I looked in the '89 XLT (351W/C6) sitting there, and see that it has the same TAB and TAD as my '89 (351W/C6 EB), with the same green hoses. What I can now see is that on my Bronco, someone cut the green hose next to the firewall that leads from the EVR and goes to the EGR.

From reading some other threads, this would account for some decrease in gas milage and not necessarly make the engine run rough. What I am wondering now is "WHY"? I don't have a check engine light coming on or anything.

Can anyone tell me a reason why a PO would cut the green lines, thus removing the EGR valve from the equation? Scratching my head......

 

[Seattle FSB]

'Cause they didn't know what it was for? Funny, 'cause if the EGR receives no vacuum and does not operate, the EVP will not change the signal to the PCM and then a code should be thrown.

 

[TNT89Bronco]

SeattleFSB - Thanks for the diagram above. It helped match the hoses to what I was seeing and figuring out what was "missing". I was trying to figure out if someone thought they were going to get more HP or something out of it. It seems like that a missing EGR should throw a Check Engine light, but it doesn't.

 

[Glayd]

SeattleFSB - Thanks for the diagram above. It helped match the hoses to what I was seeing and figuring out what was "missing". I was trying to figure out if someone thought they were going to get more HP or something out of it. It seems like that a missing EGR should throw a Check Engine light, but it doesn't.

TNT
If you read codes with that solenoid unhooked you will get a soft code. Anyways I have the same engine, trans, and year and started out at around 8 mpg when I got it home. I now am getting 16.7 mpg as of yesterday's 248 mile trip. I usually drive around 3200 rpm which on my speedo is 77 if I add 4 for the tires.
But here's what I did to get to better mpg:

changed out the y pipe and exhaust to all 3 inch, both cats and muffler also
I went with the Bossni Y pipe but a mandrel bent one will work better than what ya got now.

SixLitre tuneup followed to letter

Replaced all vacuum hoses

Synthetic fluids all around

K&N ghetto filter addon - search for Getto K&N link

also: I removed the extensoin plug-in with a thermister in it that's on your EVR and my engine idles much smoother and runs much better than it ever did but if yours is idling fine and your not throwing codes I would leave it.

hope that helps


Glayd

 

[TNT89Bronco]

Holy [email protected] Batman! 16+ MPG? I am going to have to start working on my milage! Thanks for the feedback. Now I gotta go find SixLiter's tuneup instructions.