egr and mpg

[luckythirteen13]

how much of a difference does having the egr spacer make in economy as compared to not having it. i still have my egr spacer but when i went to the dyno tuner he pulled the vacuum line off it and did something to the computer so i wont get a check engine light. is this hurting my fuel economy. with nothing but city driving (absolutly no freeway) i used to get 15mpg around town keeping the rpms at about 2800 when i shift. then i put on a sc, went to the dyno tuner and now i get 8mpg with the same driving. i can baby it and get about 11mpg but thats no fun. also, untuned before the sc i was making 225-250rwhp tops, with the sc im making just over 400rwhp. i know at 0 vacuum and under boost the egr is closed and wont hurt top end, but is having it closed when idling and cruzing hurting my mpg?

 

[18mustangs]

how much of a difference does having the egr spacer make in economy as compared to not having it. i still have my egr spacer but when i went to the dyno tuner he pulled the vacuum line off it and did something to the computer so i wont get a check engine light. is this hurting my fuel economy. with nothing but city driving (absolutly no freeway) i used to get 15mpg around town keeping the rpms at about 2800 when i shift. then i put on a sc, went to the dyno tuner and now i get 8mpg with the same driving. i can baby it and get about 11mpg but thats no fun. also, untuned before the sc i was making 225-250rwhp tops, with the sc im making just over 400rwhp. i know at 0 vacuum and under boost the egr is closed and wont hurt top end, but is having it closed when idling and cruzing hurting my mpg?

I went from 160-170 miles per tank to 180+ when I reconnected my EGR. Individual results may vary!
Tim

 

[Bad92GT]

it will cause idling issues to.. take my wonderful car for example.. i have no vaccum lol someone unhooked it all and so it would want to die.. and i always seem to run out of gas really fast

 

[luckythirteen13]

what about the electronics? the tuner made it so the computer wont care the egr is doing nothing. is the sensor there only to tell the computer if something wrong or does the electronics do something to control the opening and closing of the egr?

 

[18mustangs]

what about the electronics? the tuner made it so the computer wont care the egr is doing nothing. is the sensor there only to tell the computer if something wrong or does the electronics do something to control the opening and closing of the egr?

If the tuner shut the EGR off, then you'll have to turn it back on in the computer even if you do reconnect all of the EGR stuff.
Tim

 

[Bad92GT]

well in just a recent thread, the EGR gases are 600 degrees + so without it, it heats up your intake.. thats why after 2 minutes of running my intake is at 3rd degree burn temp.. trust me i know lol it just keeps it all cool.. i would plug it all back in.. only real reason to not have it is if you hve a straight race car

 

[luckythirteen13]

what is it that the electronics do though? i thought they were there just to tell the computer when the egr stops working. doesnt the vacuum control it? and the electronics monitor it?

 

[sunil6784]

There is a little sensor on the back of the EGR valve, called the EVP sensor (Egr Valve Position Sensor) It monitors if the valve opens or closes.

 

[luckythirteen13]

so if my computer isnt looking for any info from the sensor, will having my egr vacuum line hooked up do any damage? will i still be able to pass smog when that rolls around again? i hooked the vacuum line up. the idle seems to be better, especially in the morning when i get up for work (315am)

 

[jrichker]

Here's a book that will get you started with how the Ford electronic engine control or "computer" works.

Ford Fuel Injection & Electronic Engine Control 1988-1993 by Charles Probst :ISBN 0-8376-0301-3.

It's about $20 from Borders.com see http://www.amazon.com/ . Select boo...le to 2500 RPM. should read about 5in vacuum

 

[vristang]

so if my computer isnt looking for any info from the sensor, will having my egr vacuum line hooked up do any damage? will i still be able to pass smog when that rolls around again? i hooked the vacuum line up. the idle seems to be better, especially in the morning when i get up for work (315am)

I seriously doubt that passing emissions testing is possible without the egr. Almost no chance with boost.

 

[luckythirteen13]

the sc only makes boost above 3k rpm. the smog test is done at a max of 2200-2500 so boost is not a factor for the smog test.

all im asking is will my egr valve work if the computer is tuned not to look for it or will the vacuum line make it work?