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Old 03-12-2011   #1
1987 GTA
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look at pic

Does anyone know if there is supposed to be a hose connected to this?
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Old 03-12-2011   #2
george88gta
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Re: look at pic

Quote:
Originally Posted by 1987 GTA View Post
Does anyone know if there is supposed to be a hose connected to this?
Yes, it should have a vacumn hose attached. Hard to tell from the pic, but that may be the heater control valve.
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Old 03-12-2011   #3
djmarch
1989 Gunmetal Grey, 350 TPI, 700R4, 3:27 BW
 
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GTA Year: 1989
GTA Engine: 350 TPI Automatic
Re: look at pic

Looks like the heater control valve. You should have a hard plastic vacuum line coming from the firewall next to the ac evaporator housing that connects to this valve.
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Old 03-13-2011   #4
oldtechhero
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Re: look at pic

Looks to me like it's the EGR valve. It should have a vacuum hose connected to it. Running without EGR hurts MPG, and calls for changes to the ignition timing map.
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Old 03-13-2011   #5
FearThisGTA
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GTA Year: 1991
GTA Engine: 350 TPI Automatic
Re: look at pic

I did away with my egr, and it had absolutely no change on my mpg at all.
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Cliff Jones
1991 GTA Trans Am
w/305,231 miles
on the original motor!!!!
Time of Death on motor, 4:07pm on 05/29/2010.
Hp:211.2@4200rpms/Tq.328.5@2700rpms
Best et: 13.959@97.05mph
Best mph: 98.3
Best 60' : 1.875 on BFG Comp TA's w/ 32 lbs of air in them
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Old 03-13-2011   #6
FearThisGTA
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GTA Year: 1991
GTA Engine: 350 TPI Automatic
Re: look at pic

The answer is yes, it is your heater control valve. hth
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Cliff Jones
1991 GTA Trans Am
w/305,231 miles
on the original motor!!!!
Time of Death on motor, 4:07pm on 05/29/2010.
Hp:211.2@4200rpms/Tq.328.5@2700rpms
Best et: 13.959@97.05mph
Best mph: 98.3
Best 60' : 1.875 on BFG Comp TA's w/ 32 lbs of air in them
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Old 03-13-2011   #7
merc3065
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Re: look at pic

Heater control valve. There should be a long plastic vacuum line that goes through the firewall into the wire pack where the heater power and fan control wires comes through. Without it you don't get heat.
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Old 03-13-2011   #8
oldtechhero
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Re: look at pic

Quote:
Originally Posted by FearThisGTA View Post
I did away with my egr, and it had absolutely no change on my mpg at all.
Did you do back-to-back testing on the interstate? Stick or automatic? What axle ratio?
I tried disabling it on my '78 Camaro ( 416-headed-350, 9.8:1, 700R-4 swap, 3.08:1, 235/60R15s, 25 mpg at 65 mph ) and lost 2 mpg. In disbelief, I repeated the test. Then I started playing with my timing curve ( again ) ( I'd already tried everything MSD offered a month before ) and got 1 mpg back.
Then I tried it with my '91 Camaro. ( L03, 8.8:1, 700R-4, 2.73:1, 235/55R16, 23 mpg at 70 mph ) and again lost mpg. I swapped to a 3.42:1 axle, repeated the test, and lost 1 mpg.
EGR pays for itself.
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Old 03-13-2011   #9
george88gta
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Re: look at pic

Quote:
Originally Posted by oldtechhero View Post
Did you do back-to-back testing on the interstate? Stick or automatic? What axle ratio?
I tried disabling it on my '78 Camaro ( 416-headed-350, 9.8:1, 700R-4 swap, 3.08:1, 235/60R15s, 25 mpg at 65 mph ) and lost 2 mpg. In disbelief, I repeated the test. Then I started playing with my timing curve ( again ) ( I'd already tried everything MSD offered a month before ) and got 1 mpg back.
Then I tried it with my '91 Camaro. ( L03, 8.8:1, 700R-4, 2.73:1, 235/55R16, 23 mpg at 70 mph ) and again lost mpg. I swapped to a 3.42:1 axle, repeated the test, and lost 1 mpg.
EGR pays for itself.
Actually, that is a rather common experience with disconnecting the EGR. I dont see what added benefit you get from disabling the EGR and many times you actually lose mpg. Now the air pump is another story, it uses crankshaft HP and removing it does little or nothing to your emissions and the engine has a bit less load.
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Old 03-13-2011   #10
1987 GTA
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Re: look at pic

My heat works fine and it hasent had anything hooked to it since i got car.
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Old 03-13-2011   #11
FearThisGTA
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GTA Year: 1991
GTA Engine: 350 TPI Automatic
Re: look at pic

Quote:
Originally Posted by oldtechhero View Post
Did you do back-to-back testing on the interstate? Stick or automatic? What axle ratio?
I tried disabling it on my '78 Camaro ( 416-headed-350, 9.8:1, 700R-4 swap, 3.08:1, 235/60R15s, 25 mpg at 65 mph ) and lost 2 mpg. In disbelief, I repeated the test. Then I started playing with my timing curve ( again ) ( I'd already tried everything MSD offered a month before ) and got 1 mpg back.
Then I tried it with my '91 Camaro. ( L03, 8.8:1, 700R-4, 2.73:1, 235/55R16, 23 mpg at 70 mph ) and again lost mpg. I swapped to a 3.42:1 axle, repeated the test, and lost 1 mpg.
EGR pays for itself.
The car had about 275,000 miles or more, but less than 300k on it. The car is a factory 700r4, and 3.23 gear ratio. It is still that way as I type this, rod knock and all,lol. The only time I noticed any difference in mlg, was when I stabbed the gas. The car averaged on hwy alone around 20-21 mpg and 16-18 mpg city.
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Cliff Jones
1991 GTA Trans Am
w/305,231 miles
on the original motor!!!!
Time of Death on motor, 4:07pm on 05/29/2010.
Hp:211.2@4200rpms/Tq.328.5@2700rpms
Best et: 13.959@97.05mph
Best mph: 98.3
Best 60' : 1.875 on BFG Comp TA's w/ 32 lbs of air in them
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Old 03-14-2011   #12
oldtechhero
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Re: look at pic

Please forgive veering off topic, but only 21 mpg seems surprisingly low.
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Old 03-14-2011   #13
1badGTA
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Re: look at pic

Quote:
Originally Posted by oldtechhero View Post
Please forgive veering off topic, but only 21 mpg seems surprisingly low.
His car is not stock
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Old 03-14-2011   #14
GTAhot92
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Re: look at pic

Reason for EGR to be dissabled is to have better performance from a cleaner air intake charge. The EGR was intendid to increase fuel mileage. It's the process of Exhaust Gas Recurculation.
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Old 03-14-2011   #15
merc3065
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Re: look at pic

It also helps cool the cylinders and reduce overall emissions when cruising at certain throttle percentages.

Unless you remove the programming in the PROM and compensate for the lack of an EGR, you will always see a decrease in performance/mileage as the engine is expecting to see EGR duty cycles during normal running and will use different timing/fuel curves based off the projected results of the EGR.
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Old 03-14-2011   #16
FearThisGTA
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GTA Year: 1991
GTA Engine: 350 TPI Automatic
Re: look at pic

Quote:
Originally Posted by 1badGTA View Post
His car is not stock
That is correct, it was not...and it wont be when it goes back together.
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Cliff Jones
1991 GTA Trans Am
w/305,231 miles
on the original motor!!!!
Time of Death on motor, 4:07pm on 05/29/2010.
Hp:211.2@4200rpms/Tq.328.5@2700rpms
Best et: 13.959@97.05mph
Best mph: 98.3
Best 60' : 1.875 on BFG Comp TA's w/ 32 lbs of air in them
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Old 03-15-2011   #17
george88gta
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Talking Re: look at pic

Quote:
Originally Posted by FearThisGTA View Post
That is correct, it was not...and it wont be when it goes back together.
Always messing with Mother Nature arent you Cliff!
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Old 03-15-2011   #18
1badGTA
BAD GTA 88 5.0 TPI/T5
 
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Re: look at pic

Quote:
Originally Posted by george88gta View Post
Always messing with Mother Nature arent you Cliff!
You mean Mother GM?
Government Mother?
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1988 5.0 TPI 5-Speed GTA 1 of 809 made
22,000 miles - original floor mats
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Old 03-15-2011   #19
FearThisGTA
"The only thing to fear is.............fear itself"
 
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GTA Year: 1991
GTA Engine: 350 TPI Automatic
Re: look at pic

Quote:
Originally Posted by george88gta View Post
Always messing with Mother Nature arent you Cliff!
Who me??
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Cliff Jones
1991 GTA Trans Am
w/305,231 miles
on the original motor!!!!
Time of Death on motor, 4:07pm on 05/29/2010.
Hp:211.2@4200rpms/Tq.328.5@2700rpms
Best et: 13.959@97.05mph
Best mph: 98.3
Best 60' : 1.875 on BFG Comp TA's w/ 32 lbs of air in them
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Old 03-16-2011   #20
GTAhot92
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Re: look at pic

should be FGM
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1976 Trans Am 455 HO
1980 Turbo Trans Am
1981 Turbo Formula - Sold
1992 GTA 5th Anniversary #7
1989 Silverado
1994 Plymouth Laser R/T
1984 Maserati Biturbo
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