Vacuum lines on 89
Thread Starter
Safety Car
Joined: Jul 2003
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Vacuum lines on 89
Can anyone tell me where the vacuum line on a T next to the distributor all goes? Also, there's a small line coming from the fuel canister that runs parallel to the large line which goes to the throttle body... but where does the small line go?
Pro
Joined: Oct 1999
Posts: 515
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From: Nashua NH
T by the distributor has a check valve on it...goes to HVAC panel... small vac line running from EVAP canister goes to bottom of throttle body. There should be a picture under the hood with vac diagram...
Safety Car
Joined: Jan 2008
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From: Vero Beach Florida
On the T valve the bottom line runs into the car A/C control the top line runs to the rear of the plenum as shown on illustration where it gets vaccum from the other line runs to the cruse control. A new one cost a couple bucks most auto parts stores carry them
Thread Starter
Safety Car
Joined: Jul 2003
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Thanks for the help guys.
Now if I've deleted the EGR valve and AIR system, can I just cap off the line to the EGR solenoid? Can I remove the solenoid all together? Can I run FPR off a fitting on the intake?
Now if I've deleted the EGR valve and AIR system, can I just cap off the line to the EGR solenoid? Can I remove the solenoid all together? Can I run FPR off a fitting on the intake?
Le Mans Master
Joined: Dec 2000
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From: San Diego, Ca
The '89 doesn't use vacuum at the air pump solenoids - they're completely controlled by the ECM.
I don't know why you would change the vacuum port for the Fuel Pressure Regulator. Did you change the intake plenum for something that doesn't have it?
Cap off on any unused ports to prevent driveability issues (though you're going to create some assuming this is a stock '89 without EGR and running a non-heated O2).
I don't know why you would change the vacuum port for the Fuel Pressure Regulator. Did you change the intake plenum for something that doesn't have it?
Cap off on any unused ports to prevent driveability issues (though you're going to create some assuming this is a stock '89 without EGR and running a non-heated O2).
Thread Starter
Safety Car
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I've changed the engine to a ZZ4 and the intake over to a Super Ram and it has two vacuum ports on the back that I swapped from my original intake. IIRC, the FPR was always running from the intake. Someone else may have swapped it before I bought the car and I left it how it was.
After I finish everything, I'm taking it to have a dyno tune done. He'll take care of the EGR in the programming... I hope.
After I finish everything, I'm taking it to have a dyno tune done. He'll take care of the EGR in the programming... I hope.
Last edited by 89Corvette6spdFX3; May 13, 2009 at 03:38 PM.
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Le Mans Master
Joined: Dec 2000
Posts: 7,839
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From: San Diego, Ca
I'd use the 2 SuperRam Ports the same way the Stock Plenum was set up - one side for HVAC and Cruise; the other for your Regulator. Ports for EGR and fuel vapors should be on the throttlebody. I've never seen intake vacuum ports for anything other than the PCV on the L98.
I don't know of any person, Company or resident Einstein that's invested the time and money to tune out what EGR does at Cruise. Nor, other than the OEM's, do I know of anyone who's even captured data or conducted testing in a controlled environment. All I've seen is hearsay and self serving testimonials. The OEM's accomplish it with camming and variable valve timing, so depending on what you have in the ZZ4, it may not be an issue. If it is, the best outcome might have it giving up a mile, maybe two/gallon and plug life and shorten the CAT's life; at worse it'll still ping & pull timing (you hope) - maybe run a little hotter - when the conditions are right - not what I'd want for a new motor. Most tuners concern themselves with idle and WOT, neither condition uses EGR. Maybe it's splitting hairs, but if you slam it while it's pinging, pulling back, don't see where you've enhanced anything.
I don't know of any person, Company or resident Einstein that's invested the time and money to tune out what EGR does at Cruise. Nor, other than the OEM's, do I know of anyone who's even captured data or conducted testing in a controlled environment. All I've seen is hearsay and self serving testimonials. The OEM's accomplish it with camming and variable valve timing, so depending on what you have in the ZZ4, it may not be an issue. If it is, the best outcome might have it giving up a mile, maybe two/gallon and plug life and shorten the CAT's life; at worse it'll still ping & pull timing (you hope) - maybe run a little hotter - when the conditions are right - not what I'd want for a new motor. Most tuners concern themselves with idle and WOT, neither condition uses EGR. Maybe it's splitting hairs, but if you slam it while it's pinging, pulling back, don't see where you've enhanced anything.
Le Mans Master
Joined: Sep 2005
Posts: 6,551
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From: Jenks OK
I've changed the engine to a ZZ4 and the intake over to a Super Ram and it has two vacuum ports on the back that I swapped from my original intake. IIRC, the FPR was always running from the intake. Someone else may have swapped it before I bought the car and I left it how it was.
After I finish everything, I'm taking it to have a dyno tune done. He'll take care of the EGR in the programming... I hope.
After I finish everything, I'm taking it to have a dyno tune done. He'll take care of the EGR in the programming... I hope.
