I was wondering if I would be able to elimite the egr system. I have not emission here so thats not a prob. Also can I remove the other stuff vacum lines. And any other polution stuff??

 

I don't know why you'd want to remove the EGR system- it's there for emissions but it also makes your vehicle a little more fuel efficient.

Is the emissions system causing you problems? If not, then why fix what's not broken?

 

I was changing my heads. I broke the pipe that goes from the intake to the egr valve. So I thought my not remove it, plus it makes the intake really dirty.

 

you can block it off with a steel plate, i'd leave the vac line and wiring attached to the valve though, and just put the plate in between the valve and the intake manifold. This is because if the EGR isn't there you'll have a check engine light. You can disconnect the pipe from the bottom of the valve that goes to the exhaust manifold though. They also sell electrical pieces that attach to the egr solenoid to trick it into thinking the egr is on and working. Multiple approaches

 

Problem is, if you fool the computer into thinking the EGR is working,
when it ain't, the computer will lean out the mix when it shouldn't be
leaned out. :/

So what's the answer to removing the EGR then? :/

Is there a way to stop the computer from throwing a code and not
lean-out the mixture both? :/

-------------------------

There are coolant lines running through the manifold near the EGR
because the exhaust gas otherwise would heat it up way too much.
Without the exhaust gas being ran into the intake manifold, the lines
could also be removed. :)

--------------------

There's the air pump system too. ;)
OP, what year are you talking about?

--------------

In the light trucks, what year did they switch from EEC-IV to OBD-II?

Alvin in AZ

 

The truck is a 93 maf sensor. The egr valve does not have a plug on it.

 

air pump is all ready gone.

 

The code that is generated is "EGR opening not detected" but it doesn't turn on the CEL. The computer adjusts for the EGR being closed all of the time.

The plug in eliminators are just a circuit that feeds the computer somewhere between .5 and .9 volts which is what the EGR sensor would show when the valve is closed.

http://www.fordfuelinjection.com/?p=35

 

Cool, thanks for all that, Al. :)
At some point I know-ed that and at another point I un-knowed that. LOL :)

http://www.panix.com/~alvinj/file12/egr-SubFord.jpg
(notice SubFord's circuit diagram is the harness not the EVP itself)
(drawn that way is more helpful while duplicating the circuit)
http://www.panix.com/~alvinj/file12/egr-evp.jpg
http://www.panix.com/~alvinj/file12/egr-BW.jpg

So all this got me off my lazy butt and measured two of my EVP's resistances
(both are gray sensors and measured as they are on the vehicle) and got...

3450 ohms and 3550 ohms between circuits 351 and 359.
Also...
525 ohms and 600 ohms between circuits 351 and 352.

Since those are the resistances the computers are used to...
Should I get resistors close to those values as opposed to the values listed in
the diagrams?

{edit}
Looks like SubFord's voltage is for a black-EVP and not a gray-EVP like mine.
So I answered my own question on that one. LOL
(I need to mark my calender;)

Alvin in AZ

 

Been messing with EGR stuff for over 4 hours now. LOL :)

I have three gray EVP's altogether and ran the '91 F150 and checked
the voltage from each one...
0.40v
0.45v
0.50v

After the engine runs a little while (in closed loop?) opening the throttle
a little, raises the voltage on the Br/Gn wire using the Gy/R wire as a
ground. :)

Also figured out Radio Shack has the resistors needed. A 3.3k ohm with
a 330 ohm will produce the needed ~0.46v voltage drop.

Using SubFord's diagram using my values ought to turn out real nice for
those of us with gray EVPs. :)

I still haven't driven it with the vacuum line plugged but it's plugged
now and so ready to see if there is any felt difference next time I go
somewhere. ;)

Alvin in AZ
http://www.radioshack.com/product/in...6&clickid=cart
http://www.radioshack.com/product/in...9&clickid=cart

 

Sorry, but no you can not eliminate your particular EGR system. It determines EGR operation based on flow, if it doesnt get a flow you will always have the CEL on all the time. You will also get a code for it being on as well.

The older EGR system determined position of the EGR valve not the flow and yes you could block it off and let the computer think it is operating.

The O2 sensor is how the computer determines the actual mixture, and it does really well in determining the right fuel to air ratio.

Personally, I have run my truck with and without EGR and noticed ZERO seat of the pants dyno differences. So I run with it, because it gets me a few tenths of a gallon per mile that I may not otherwise acheive on long drives (if I ever bother to depress myself with calculating the mileage on a C-6 equiped, 33" shod, and factory geared 351).

The AIR pump is a different system unrelated to the EGR, and its controls should be left plugged in to avoid codes, even if there isnt a vacuum line attached to the controls for the diverter valves.

 

Sorry OP - didn't realise you don't have the same system as my '89

Alvin,

After speaking with an electrical engineer I work with. He suggested a potentiometer could also be used if you don't feel like soldering together a circuit. Wire the sweep to connection 352 in subfords diagram and dial in the voltage you need the computer to see. He seems to think it isn't that important the overall reissitance of the circuit as long as the correct voltage is output to the computer.

That being said - I came across much of this information after I installed the plug-in eliminator. I'm happy with it, seems they did a nice job protecting it from heat/vibration so it should be reliable.

The reason for me doing the EGR delete was the cost of replacing all of the parts in the EGR system. The pipe, sensor, and valve needed replacing. It was $250 vs $40 so I took the cheaper route. The truck is not a DD for me so gas milage was not a concern.

 

This is really cool! :)
We are getting into this thing like we mean business. :)

What I didn't report yesterday (didn't think it would be interesting to anyone
so I didn't type it out :/) was that the ~1/2 volt signal coming off of two of
those EVP's made the needle vibrate bad, and at times, dance like crazy, the
most stable one did too but was, for the most part, pretty stable, but what
would you expect from a potentiometer fastened directly to an engine
anyway? LOL :)

He's got a cool theory there, but in practice it's not so good, see it? ;)

That's the difference between a dumb guy like me "on the ground" and a
smarter guy just thinking about it "in the office". It's always been that way
and always will be. I dug ditches and climbed poles for a living. LOL :)
I've ran across this situation thousands of times in my life, believe it? ;)

Also a guy "should" solder in the potentiometer too. ;)
$2 for two packs of 5 fixed resistors is enough for five vehicles.

I really like what he said tho, no kidding on that. The idea you could dial in
the value and knowing the current isn't all that important too. All it takes to
turn 5 volts into about one tenth that is a 1 to 10 ratio on the resistors, so
it's not like it's complicated or something. ;)

I feel as tho he could really help us out tho. :) He's got the potential to do
that but he's going to have to work at it a lot harder than he's done so far.
Is he up to the challenge? ;)

I'm retired and don't drive to town (or anywhere else;) unless I absolutely
have to. So I'm hoping to sell or give-away the two real nice EGRs I'm going
to have when I get done robbing parts off two pickups to fix up one Bronco.

The third EGR's pipe was so weak I broke it and removed it with my hand.

Noticed yesterday a noisy bearing in the air pump on the '91 F150...
That pickup has only got 73,000 miles on it! :/

A guy could get it out now, clean and repack the one bearing and replace
the 6203 bearing and make it last a long time for real cheap. Another
potential item for saving someone money and making less "bad stuff" than
if I kept it and used it myself. x2 since I have two low mileage air pumps. ;)

Alvin in AZ

 

Finally went to town today and drove the '91 F150 (73k miles) with the EGR
vacuum hose plugged. Got a Check Engine Light! :)

Stopped and (without killing the engine) put the vacuum hose back on the
EGR and the light went off later, not sure how long it took.

It might have been my imagination but the engine at about 2200rpm going
down the freeway seemed labored. Like it wasn't advancing the spark as
far as it would otherwise or something like that. Reminded me of that "feel"
anyway.

Going to try just blocking it with a plate next and see how it acts/feels. :)

Alvin in AZ
ps- as far as plugging the manifold it looks like it could be tapped with 3/8"
pipe threads since the hole is ~9/16". :)

 

Tapped and plugged the 9/16" hole in the upper manifold and left all the
EGR stuff in place. So that fooled the ECM into thinking the EGR was
working when it wasn't.

It was easier for me to plug it than make a block-off plate since I already
had the plugs and the 3/8" tapered pipe tap. YMMV on that. Also I'm just
experimenting and the plug can be removed easy enough.

The sucker now -feels- more powerful just a little above idle! :)
All I can tell you is how it "felt" to me.

At this point I believe that is the way to do it. :)

Looked for a quote but couldn't find it where a guy mentioned this method
not hurting anything because the ECM would correct the mixture by way
of feedback from the O2 sensor. What do you think?

Now, how do you fool the ECM, using fixed resistors, the EGR is working?

Does the ECM need a certain voltage at idle and another at mid throttle?

Alvin in AZ