When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
The one that goes into the firewall is for cruise and cruise brake switch. There is also vacuum lines that go to a plastic ball and the evap system. I removed all that crap on my 85 vette. The passenger side vacuum line is for the interior heater/ac.
The one that goes into the firewall is for cruise and cruise brake switch. There is also vacuum lines that go to a plastic ball and the evap system. I removed all that crap on my 85 vette. The passenger side vacuum line is for the interior heater/ac.
So these lines that are out in my car, would that affect the mpg or anything, stalling, etc.?
Does your EGR Solenoid (mounted under the thermostat housing bolts) have the vacuum line supplied to it? IF it is the vacuum line that supplies the EGR then you will have issues at low rpm's and idling sometimes. The EGR solenoid needs to have a constant source of vacuum for it to operate properly. The solenoid for the EGR system is mounted like I mentioned earlier on one of the two bolts holding the thermostat housing. It needs vacuum to be able to operate the EGR valve. There are a couple vacuum lines that supply the ball (vacuum storage) and the emissions equipment. If I were doing the work I would replace every inch of dried out Vacuum hoses and even replace the semi-rigid hard plastic tubing as it is broken all over on my 1988 C4.
Removing emissions without knowing what you are doing is downright silly, there are plenty of experienced Corvette Owners that have done it properly. I keep the emissions equipment working on my C4 as I live in a State that does a lot of emissions testing and requires it to all be there during the annual safety inspection.
There should be a diagram under your hood someplace that shows the routing of the Emissions vacuum lines. BTW, it appears that your EGR does not have vacuum line going to it, be sure and check, that might be where the hose was intended to go.
Good Luck getting your Corvette working properly and back on the road!
Does your EGR Solenoid (mounted under the thermostat housing bolts) have the vacuum line supplied to it? IF it is the vacuum line that supplies the EGR then you will have issues at low rpm's and idling sometimes. The EGR solenoid needs to have a constant source of vacuum for it to operate properly. The solenoid for the EGR system is mounted like I mentioned earlier on one of the two bolts holding the thermostat housing. It needs vacuum to be able to operate the EGR valve. There are a couple vacuum lines that supply the ball (vacuum storage) and the emissions equipment. If I were doing the work I would replace every inch of dried out Vacuum hoses and even replace the semi-rigid hard plastic tubing as it is broken all over on my 1988 C4.
Removing emissions without knowing what you are doing is downright silly, there are plenty of experienced Corvette Owners that have done it properly. I keep the emissions equipment working on my C4 as I live in a State that does a lot of emissions testing and requires it to all be there during the annual safety inspection.
There should be a diagram under your hood someplace that shows the routing of the Emissions vacuum lines. BTW, it appears that your EGR does not have vacuum line going to it, be sure and check, that might be where the hose was intended to go.
Good Luck getting your Corvette working properly and back on the road!
Chris
Hollup dude. Is the EGR the circle thing above the battery? No vacuum line is connected
That line goes down to the vacuum resevoir for you AC and cruise. It should run along the drivers side to a "T". One side of the T is vacuum for the cruise and the other goes up behind the plenum to another T with a one way valve. One side goes to the plenum and the other goes through the firewall to the AC inside. It has nothing to do with the EGR. Unfortunately the diagram below does not show the cruise control T.
#4 on this diagram
There is a larger vacuum line that runs from the PCV area down to the charcoal canister/valve assembly in this area as well.
That line goes down to the vacuum resevoir for you AC and cruise. It should run along the drivers side to a "T". One side of the T is vacuum for the cruise and the other goes up behind the plenum to another T with a one way valve. One side goes to the plenum and the other goes through the firewall to the AC inside. It has nothing to do with the EGR. Unfortunately the diagram below does not show the cruise control T.
#4 on this diagram
There is a larger vacuum line that runs from the PCV area down to the charcoal canister/valve assembly in this area as well.
Okay, thanks. So hold on
that circle looking thing that I circled, I dont know what that is. Seems like a vacuum hose going to it. But on my 85 I dont have anything attached to it from that side. What is it and could that be my problem?
Yes it is a large vacuum line and yes there is a vacuum line for the cruise control in that area on the drivers side frame rail. Yes they even go to the front left area near the left headlight to that little round vacuum storage device.
I do recall saying "IF" and I did not say it "WAS" the "EGR" vacuum line. I still see no vacuum line going to the EGR Vacuum Solenoid. No vacuum, no working EGR.
The EGR is directly under the intake manifold and has a vacuum line coming to it from the EGR Vacuum solenoid. There is also a Fuel pressure regulator near the EGR as well and they both have vacuum hoses attached to them. You should be able to identify the EGR valve as its hose goes to the EGR vacuum solenoid. It is usually a smaller walled vacuum line but not always. The Fuel Pressure Regulator is fairly easy to identify as it has screws in a circle holding the diaphragm in place. The EGR does not have all the little screws holding it together.
The EGR can affect the performance of your Corvette if it is not working properly. I am not an expert on the 1985 Model but EGR's have been on cars for decades and I suspect yours is similar to what is on my 1988 C4. The Vacuum solenoid has two wires supplying it with power to activate. The ECM uses PWM to control the EGR. On my 1988 I found out that I had an EGR problem when I had the emissions tested. The NOX was out of sight during the test which indicates the EGR is bad. On my C4 I replaced the EGR, Vacuum Solenoid, Fuel Injectors,FPR, fuel pump and Fuel filter. Cleaning out the blocked EGR passageways was a real PIA and I used carbon remover and wire brushes and air pressure to get all the carbon out. I figured that while I was there I might as well fix this or that so I removed the intake parts and sand blasted them and re-painted the parts. It was a lot of work but worth it in the end.
If you don't have a set already be sure to get yourself a copy of the Factory Service Manuals (my 1988 C4 has two red books and an addendum as well. The manuals are priceless when you have problems with a C4 like the EGR system.
Good Luck and get your Beautiful Corvette back on the road again!
Best regards,
Chris
Yes it is a large vacuum line and yes there is a vacuum line for the cruise control in that area on the drivers side frame rail. Yes they even go to the front left area near the left headlight to that little round vacuum storage device.
I do recall saying "IF" and I did not say it "WAS" the "EGR" vacuum line. I still see no vacuum line going to the EGR Vacuum Solenoid. No vacuum, no working EGR.
The EGR is directly under the intake manifold and has a vacuum line coming to it from the EGR Vacuum solenoid. There is also a Fuel pressure regulator near the EGR as well and they both have vacuum hoses attached to them. You should be able to identify the EGR valve as its hose goes to the EGR vacuum solenoid. It is usually a smaller walled vacuum line but not always. The Fuel Pressure Regulator is fairly easy to identify as it has screws in a circle holding the diaphragm in place. The EGR does not have all the little screws holding it together.
The EGR can affect the performance of your Corvette if it is not working properly. I am not an expert on the 1985 Model but EGR's have been on cars for decades and I suspect yours is similar to what is on my 1988 C4. The Vacuum solenoid has two wires supplying it with power to activate. The ECM uses PWM to control the EGR. On my 1988 I found out that I had an EGR problem when I had the emissions tested. The NOX was out of sight during the test which indicates the EGR is bad. On my C4 I replaced the EGR, Vacuum Solenoid, Fuel Injectors,FPR, fuel pump and Fuel filter. Cleaning out the blocked EGR passageways was a real PIA and I used carbon remover and wire brushes and air pressure to get all the carbon out. I figured that while I was there I might as well fix this or that so I removed the intake parts and sand blasted them and re-painted the parts. It was a lot of work but worth it in the end.
If you don't have a set already be sure to get yourself a copy of the Factory Service Manuals (my 1988 C4 has two red books and an addendum as well. The manuals are priceless when you have problems with a C4 like the EGR system.
Good Luck and get your Beautiful Corvette back on the road again!
Best regards,
Chris
All correct. I can post a pic of the EGR vacuum line diagram if Mason123 needs it. Sorry if I dissed you, didn't mean to.
Does your EGR Solenoid (mounted under the thermostat housing bolts) have the vacuum line supplied to it? IF it is the vacuum line that supplies the EGR then you will have issues at low rpm's and idling sometimes. The EGR solenoid needs to have a constant source of vacuum for it to operate properly. The solenoid for the EGR system is mounted like I mentioned earlier on one of the two bolts holding the thermostat housing. It needs vacuum to be able to operate the EGR valve. There are a couple vacuum lines that supply the ball (vacuum storage) and the emissions equipment. If I were doing the work I would replace every inch of dried out Vacuum hoses and even replace the semi-rigid hard plastic tubing as it is broken all over on my 1988 C4.
Removing emissions without knowing what you are doing is downright silly, there are plenty of experienced Corvette Owners that have done it properly. I keep the emissions equipment working on my C4 as I live in a State that does a lot of emissions testing and requires it to all be there during the annual safety inspection.
There should be a diagram under your hood someplace that shows the routing of the Emissions vacuum lines. BTW, it appears that your EGR does not have vacuum line going to it, be sure and check, that might be where the hose was intended to go.
Good Luck getting your Corvette working properly and back on the road!
Chris
Originally Posted by ctmccloskey
Yes it is a large vacuum line and yes there is a vacuum line for the cruise control in that area on the drivers side frame rail. Yes they even go to the front left area near the left headlight to that little round vacuum storage device.
I do recall saying "IF" and I did not say it "WAS" the "EGR" vacuum line. I still see no vacuum line going to the EGR Vacuum Solenoid. No vacuum, no working EGR.
The EGR is directly under the intake manifold and has a vacuum line coming to it from the EGR Vacuum solenoid. There is also a Fuel pressure regulator near the EGR as well and they both have vacuum hoses attached to them. You should be able to identify the EGR valve as its hose goes to the EGR vacuum solenoid. It is usually a smaller walled vacuum line but not always. The Fuel Pressure Regulator is fairly easy to identify as it has screws in a circle holding the diaphragm in place. The EGR does not have all the little screws holding it together.
The EGR can affect the performance of your Corvette if it is not working properly. I am not an expert on the 1985 Model but EGR's have been on cars for decades and I suspect yours is similar to what is on my 1988 C4. The Vacuum solenoid has two wires supplying it with power to activate. The ECM uses PWM to control the EGR. On my 1988 I found out that I had an EGR problem when I had the emissions tested. The NOX was out of sight during the test which indicates the EGR is bad. On my C4 I replaced the EGR, Vacuum Solenoid, Fuel Injectors,FPR, fuel pump and Fuel filter. Cleaning out the blocked EGR passageways was a real PIA and I used carbon remover and wire brushes and air pressure to get all the carbon out. I figured that while I was there I might as well fix this or that so I removed the intake parts and sand blasted them and re-painted the parts. It was a lot of work but worth it in the end.
If you don't have a set already be sure to get yourself a copy of the Factory Service Manuals (my 1988 C4 has two red books and an addendum as well. The manuals are priceless when you have problems with a C4 like the EGR system.
Good Luck and get your Beautiful Corvette back on the road again!
Best regards,
Chris
sorry Chris, but this is model year 1985. the egr solenoid is mounted on the right-rear of the lower intake manifold around the #8 cylinder. ONE YEAR ONLY CONFIGURATION.
my best guess from the OP's original pic is the vacuum line in question goes to the bottom of the throttle body. from the pic, it looks like there is a line going back to a "tee" for the cruise control
in the above pic, hard to tell, but it looks like there are no vacuum lines going to the throttle body...
in the above photo (EGR solenoid) , one of the plastic lines goes to the EGR valve, and the other to the throttle body. at the throttle body, there is a "tee" - it looks like the line in question goes to that "tee." note 1985 is a one year configuration.
here's a pic of my 85. vacuum lines pretty much factory. there should be two 5/32" lines - one goes to the throttle body, and one goes back to a "tee" near the master cylinder - one side goes to the cruise control and the other runs along the firewall the RH-rear plenum.
sorry Chris, but this is model year 1985. the egr solenoid is mounted on the right-rear of the lower intake manifold around the #8 cylinder. ONE YEAR ONLY CONFIGURATION.
my best guess from the OP's original pic is the vacuum line in question goes to the bottom of the throttle body. from the pic, it looks like there is a line going back to a "tee" for the cruise control
in the above pic, hard to tell, but it looks like there are no vacuum lines going to the throttle body...
in the above photo (EGR solenoid) , one of the plastic lines goes to the EGR valve, and the other to the throttle body. at the throttle body, there is a "tee" - it looks like the line in question goes to that "tee." note 1985 is a one year configuration.
here's a pic of my 85. vacuum lines pretty much factory. there should be two 5/32" lines - one goes to the throttle body, and one goes back to a "tee" near the master cylinder - one side goes to the cruise control and the other runs along the firewall the RH-rear plenum.
So would that vacuum line that seems to be disconnected be the cause of the problems such as the idle and stalling?
So would that vacuum line that seems to be disconnected be the cause of the problems such as the idle and stalling?
does the picture at the very top help
any connected or disconnected vacuum line can be suspect - too many variables. just because you have a point to point connection, doesn't mean you can't have a vacuum leak. remember, if original, those rubber hoses are coming up on 35 years old.
questions - do you have anything connected to the vacuum port on the bottom of the throttle body? when was the last time your throttle body was cleaned?
side note: several years ago, I replaced all my rubber vacuum, and emission hoses. made a noticeable difference in my idle quality.
Clean the throttle body and add a can of BG 44KFuel Injection system cleaner to the fuel tank to clear all the junk out of the system. Do what Joe did and replace every inch of your vacuum lines. The vacuum system is important to your car and it's performance. If that seems overwhelming look at a C3 like my 1968 and the dozens of vacuum hoses all marked with color stripes. That was a nightmare. The only line on the C4 that gave me a fit was the one going to the brake pedal to disengage the cruise control. I have 5 crushed discs in my back and that hurts going under the steering wheel section of the dashboard
The throttle body bushing have a tendency to get looser as the age, check it to be sure it is not another vacuum leak and this one clearly affects your idle.
By the way, Joe C How do you keep your C4 THAT clean? I am always amazed when I see an engine that looks cleaner than when it was brand new. That is some amazing work you do there my friend!
any connected or disconnected vacuum line can be suspect - too many variables. just because you have a point to point connection, doesn't mean you can't have a vacuum leak. remember, if original, those rubber hoses are coming up on 35 years old.
questions - do you have anything connected to the vacuum port on the bottom of the throttle body? when was the last time your throttle body was cleaned?
side note: several years ago, I replaced all my rubber vacuum, and emission hoses. made a noticeable difference in my idle quality.
Actually cleaned the throttle body a few days ago! I dont know if I have a vacuum loke under the throttle body, I tried checking but Im have problems looking I guess where exactly it should be.
Actually cleaned the throttle body a few days ago! I don’t know if I have a vacuum loke under the throttle body, I tried checking but I’m have problems looking I guess where exactly it should be.
