EGR removed what vacuums do I need
#1
EGR removed what vacuums do I need
Hi, the EGR system on my "87 4bbl 305 (H) E4ME" is removed. I want to know which vacuum hoses I need to properly run the car.
I looked at this diagram:
and plugged every vacuum outlet of the carb except the one on the back that goes to the VAC.
Do I actually need to route a hose to anything else so the engine can run properly?
By some reason unknown to me I don't have a temp sensor in the air filter box, but I have the VAC motor which isn't connected anywhere.
Thanks in advance!
I looked at this diagram:
and plugged every vacuum outlet of the carb except the one on the back that goes to the VAC.
Do I actually need to route a hose to anything else so the engine can run properly?
By some reason unknown to me I don't have a temp sensor in the air filter box, but I have the VAC motor which isn't connected anywhere.
Thanks in advance!
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Car: 84 Z28, '15 Colorado
Engine: L69
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Re: EGR removed what vacuums do I need
The only vacuum lines that I still have hooked up are:
Tank to canister
VAC sensor to carb
Cruise control
Tank to canister
VAC sensor to carb
Cruise control
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Car: 84 Z28, '15 Colorado
Engine: L69
Transmission: A4
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Re: EGR removed what vacuums do I need
It allows the gas tank to vent fumes out without smelling like gas. At least that's my understanding of it....
#6
Re: EGR removed what vacuums do I need
Yeah it vents the gas tank fumes to the intake to prevent them from leaking into the atmosphere as that is a pollutant. Newer cars will throw codes for a depressurized gas tank, which is allowing fuel vapors into the atmosphere, which will fail you for emissions. Usually caused by a faulty gas cap too...
(Although I love that smell of fuel....)
(Although I love that smell of fuel....)
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Car: 87 Camaro Z-28
Engine: 305 LG4 w/ E4ME carb
Transmission: 700R4
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Re: EGR removed what vacuums do I need
I think they are all helpful buts that's me.
The EGR is designed to cool off our engines by recycling some exhaust gases to dilute/reduce the amount of oxygen. While it's an ugly mess that includes a smog pump and funky air hoses it works preventing smog from being created. Early 70's to I guess late 80's engines had similar setups thus the name smogger engines. But hey, there's a lot less smog potentially and the engine stays cooler. I'm sure there's more to EGR but that at least part of it.
The PVC is a super old idea so it might be called a standard for engines. Gases are passed from the top of the engine back into the combustion chamber. The engine stays cleaner and while there's more benefit that's the one I think about with PVC.
The vacuum canister. Yep. We have a mess to look at but there are a few things Cheby was doing here. When your engine is cold stored gases from the charcoal canister get sucked in. So it's enriched air for better start up and better, it's free gas! There's another time for our '87s that fuel vapors are sucked into the engine. I think that condition is off idle but whatever it's more free gas. When we shut down our cars gas from the fuel bowl is allowed to pass to the charcoal canister for storage. Little fuel vapor molecules I guess attach themselves to the rough surface of charcoal pieces. The charcoal is the same stuff used in a fish tank and because it's really porous holds a lot of vapor. Of course in the spaghetti of vacuum lines and control valves the fuel tank empties it's gases into the charcoal canister as well. Same purpose. There is a bit of computer controlling for some of the vacuum actions and some are one way passages depending on vacuum presence or absence. I once read without the canister set up that a couple of gallons of fuel could just evaporate away every week. So ugly looking though.
The '87 carbs (and maybe '86 carbs though I'm not sure about '86 carbs) go all out and even have an additional port to better manage fumes. With the '87 too there is an additional valve or two hooked up in that mess. That's the best GM could do to reduce pollution with an OBDI computer I guess. In cold start situations and excessively hot burns the carb's vacuum setup helps our engine burn cleaner and smoother plus saves some gas. Sometimes there is a gas smell if everything is disconnected and/or plugged. Hope not.
The VAC motor and temp sensor. This is a vacuum temp sensor and it's an old idea that when the air canister if cold then that sensor has wax to open or close based on melting. At the appropriate time the temp sensor allows vacuum from the carb/engine to open/close a diverter valve inside the air canister so that hot air gets to the carb. It's a cool thing to keep connected.
The one vacuum line for sure that you could unplug with minimal impact is the TVS. When the engine is cold the TVS routes hotter air to the carb fast and helps the engine run that much smoother. OBDI is a combo of early computer and emissions parts. There are later/better designed engines that don't use EGR but our LG4s did. I decided to leave it all place and keep the complaints about exhaust smells from my wife reasonably toned down LOL! Actually, a while back I learned to listen to her complaints about smells after suffering serious complications when I ignored her complaints about an industrial fume condition. Nothing to do with the exhaust in that case but now I consider her input closely. Her nose must be half blood hound! If your actually racing then just plug it all up except PVC, EGR and gas tank-canister-carb.
The EGR is designed to cool off our engines by recycling some exhaust gases to dilute/reduce the amount of oxygen. While it's an ugly mess that includes a smog pump and funky air hoses it works preventing smog from being created. Early 70's to I guess late 80's engines had similar setups thus the name smogger engines. But hey, there's a lot less smog potentially and the engine stays cooler. I'm sure there's more to EGR but that at least part of it.
The PVC is a super old idea so it might be called a standard for engines. Gases are passed from the top of the engine back into the combustion chamber. The engine stays cleaner and while there's more benefit that's the one I think about with PVC.
The vacuum canister. Yep. We have a mess to look at but there are a few things Cheby was doing here. When your engine is cold stored gases from the charcoal canister get sucked in. So it's enriched air for better start up and better, it's free gas! There's another time for our '87s that fuel vapors are sucked into the engine. I think that condition is off idle but whatever it's more free gas. When we shut down our cars gas from the fuel bowl is allowed to pass to the charcoal canister for storage. Little fuel vapor molecules I guess attach themselves to the rough surface of charcoal pieces. The charcoal is the same stuff used in a fish tank and because it's really porous holds a lot of vapor. Of course in the spaghetti of vacuum lines and control valves the fuel tank empties it's gases into the charcoal canister as well. Same purpose. There is a bit of computer controlling for some of the vacuum actions and some are one way passages depending on vacuum presence or absence. I once read without the canister set up that a couple of gallons of fuel could just evaporate away every week. So ugly looking though.
The '87 carbs (and maybe '86 carbs though I'm not sure about '86 carbs) go all out and even have an additional port to better manage fumes. With the '87 too there is an additional valve or two hooked up in that mess. That's the best GM could do to reduce pollution with an OBDI computer I guess. In cold start situations and excessively hot burns the carb's vacuum setup helps our engine burn cleaner and smoother plus saves some gas. Sometimes there is a gas smell if everything is disconnected and/or plugged. Hope not.
The VAC motor and temp sensor. This is a vacuum temp sensor and it's an old idea that when the air canister if cold then that sensor has wax to open or close based on melting. At the appropriate time the temp sensor allows vacuum from the carb/engine to open/close a diverter valve inside the air canister so that hot air gets to the carb. It's a cool thing to keep connected.
The one vacuum line for sure that you could unplug with minimal impact is the TVS. When the engine is cold the TVS routes hotter air to the carb fast and helps the engine run that much smoother. OBDI is a combo of early computer and emissions parts. There are later/better designed engines that don't use EGR but our LG4s did. I decided to leave it all place and keep the complaints about exhaust smells from my wife reasonably toned down LOL! Actually, a while back I learned to listen to her complaints about smells after suffering serious complications when I ignored her complaints about an industrial fume condition. Nothing to do with the exhaust in that case but now I consider her input closely. Her nose must be half blood hound! If your actually racing then just plug it all up except PVC, EGR and gas tank-canister-carb.
Hi, the EGR system on my "87 4bbl 305 (H) E4ME" is removed. I want to know which vacuum hoses I need to properly run the car.
I looked at this diagram:
and plugged every vacuum outlet of the carb except the one on the back that goes to the VAC.
Do I actually need to route a hose to anything else so the engine can run properly?
By some reason unknown to me I don't have a temp sensor in the air filter box, but I have the VAC motor which isn't connected anywhere.
Thanks in advance!
I looked at this diagram:
and plugged every vacuum outlet of the carb except the one on the back that goes to the VAC.
Do I actually need to route a hose to anything else so the engine can run properly?
By some reason unknown to me I don't have a temp sensor in the air filter box, but I have the VAC motor which isn't connected anywhere.
Thanks in advance!
Last edited by scooter500; 08-05-2011 at 10:36 PM. Reason: fixed a couple typos
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#9
Re: EGR removed what vacuums do I need
I think they are all helpful buts that's me.
The EGR is designed to cool off our engines by recycling some exhaust gases to dilute/reduce the amount of oxygen. While it's an ugly mess that includes a smog pump and funky air hoses it works preventing smog from being created. Early 70's to I guess late 80's engines had similar setups thus the name smogger engines. But hey, there's a lot less smog potentially and the engine stays cooler. I'm sure there's more to EGR but that at least part of it.
The PVC is a super old idea so it might be called a standard for engines. Gases are passed from the top of the engine back into the combustion chamber. The engine stays cleaner and while there's more benefit that's the one I think about with PVC.
The vacuum canister. Yep. We have a mess to look at but there are a few things Cheby was doing here. When your engine is cold stored gases from the charcoal canister get sucked in. So it's enriched air for better start up and better, it's free gas! There's another time for our '87s that fuel vapors are sucked into the engine. I think that condition is off idle but whatever it's more free gas. When we shut down our cars gas from the fuel bowl is allowed to pass to the charcoal canister for storage. Little fuel vapor molecules I guess attach themselves to the rough surface of charcoal pieces. The charcoal is the same stuff used in a fish tank and because it's really porous holds a lot of vapor. Of course in the spaghetti of vacuum lines and control valves the fuel tank empties it's gases into the charcoal canister as well. Same purpose. There is a bit of computer controlling for some of the vacuum actions and some are one way passages depending on vacuum presence or absence. I once read without the canister set up that a couple of gallons of fuel could just evaporate away every week. So ugly looking though.
The '87 carbs (and maybe '86 carbs though I'm not sure about '86 carbs) go all out and even have an additional port to better manage fumes. With the '87 too there is an additional valve or two hooked up in that mess. That's the best GM could do to reduce pollution with an OBDI computer I guess. In cold start situations and excessively hot burns the carb's vacuum setup helps our engine burn cleaner and smoother plus saves some gas. Sometimes there is a gas smell if everything is disconnected and/or plugged. Hope not.
The VAC motor and temp sensor. This is a vacuum temp sensor and it's an old idea that when the air canister if cold then that sensor has wax to open or close based on melting. At the appropriate time the temp sensor allows vacuum from the carb/engine to open/close a diverter valve inside the air canister so that hot air gets to the carb. It's a cool thing to keep connected.
The one vacuum line for sure that you could unplug with minimal impact is the TVS. When the engine is cold the TVS routes hotter air to the carb fast and helps the engine run that much smoother. OBDI is a combo of early computer and emissions parts. There are later/better designed engines that don't use EGR but our LG4s did. I decided to leave it all place and keep the complaints about exhaust smells from my wife reasonably toned down LOL! Actually, a while back I learned to listen to her complaints about smells after suffering serious complications when I ignored her complaints about an industrial fume condition. Nothing to do with the exhaust in that case but now I consider her input closely. Her nose must be half blood hound! If your actually racing then just plug it all up except PVC, EGR and gas tank-canister-carb.
The EGR is designed to cool off our engines by recycling some exhaust gases to dilute/reduce the amount of oxygen. While it's an ugly mess that includes a smog pump and funky air hoses it works preventing smog from being created. Early 70's to I guess late 80's engines had similar setups thus the name smogger engines. But hey, there's a lot less smog potentially and the engine stays cooler. I'm sure there's more to EGR but that at least part of it.
The PVC is a super old idea so it might be called a standard for engines. Gases are passed from the top of the engine back into the combustion chamber. The engine stays cleaner and while there's more benefit that's the one I think about with PVC.
The vacuum canister. Yep. We have a mess to look at but there are a few things Cheby was doing here. When your engine is cold stored gases from the charcoal canister get sucked in. So it's enriched air for better start up and better, it's free gas! There's another time for our '87s that fuel vapors are sucked into the engine. I think that condition is off idle but whatever it's more free gas. When we shut down our cars gas from the fuel bowl is allowed to pass to the charcoal canister for storage. Little fuel vapor molecules I guess attach themselves to the rough surface of charcoal pieces. The charcoal is the same stuff used in a fish tank and because it's really porous holds a lot of vapor. Of course in the spaghetti of vacuum lines and control valves the fuel tank empties it's gases into the charcoal canister as well. Same purpose. There is a bit of computer controlling for some of the vacuum actions and some are one way passages depending on vacuum presence or absence. I once read without the canister set up that a couple of gallons of fuel could just evaporate away every week. So ugly looking though.
The '87 carbs (and maybe '86 carbs though I'm not sure about '86 carbs) go all out and even have an additional port to better manage fumes. With the '87 too there is an additional valve or two hooked up in that mess. That's the best GM could do to reduce pollution with an OBDI computer I guess. In cold start situations and excessively hot burns the carb's vacuum setup helps our engine burn cleaner and smoother plus saves some gas. Sometimes there is a gas smell if everything is disconnected and/or plugged. Hope not.
The VAC motor and temp sensor. This is a vacuum temp sensor and it's an old idea that when the air canister if cold then that sensor has wax to open or close based on melting. At the appropriate time the temp sensor allows vacuum from the carb/engine to open/close a diverter valve inside the air canister so that hot air gets to the carb. It's a cool thing to keep connected.
The one vacuum line for sure that you could unplug with minimal impact is the TVS. When the engine is cold the TVS routes hotter air to the carb fast and helps the engine run that much smoother. OBDI is a combo of early computer and emissions parts. There are later/better designed engines that don't use EGR but our LG4s did. I decided to leave it all place and keep the complaints about exhaust smells from my wife reasonably toned down LOL! Actually, a while back I learned to listen to her complaints about smells after suffering serious complications when I ignored her complaints about an industrial fume condition. Nothing to do with the exhaust in that case but now I consider her input closely. Her nose must be half blood hound! If your actually racing then just plug it all up except PVC, EGR and gas tank-canister-carb.
#11
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Re: EGR removed what vacuums do I need
how about pics of e4me setups without egr??? i too have an 87 that i removed the egr from(and a couple of other things) and i wanna make sure i have everything plugged in the way its supposed to be, i kept the pcv and evap and im hoping i have it plugged in right
#13
Re: EGR removed what vacuums do I need
Can you describe how the PCV hoses are plugged?
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Re: EGR removed what vacuums do I need
PCV is not capped... it runs from the front of the carb to the pcv valve... and another comes from the front of the carb to the evap, there is also a small vac line that comes from the firewall wiring harness and goes to the rear of the carb... then there is hard "fuel line" coming from the rear of the carb going to the drivers side of the firewall, ill post a pic when im at my home computer
#15
Re: EGR removed what vacuums do I need
I'm in the dark with how the PCV valve works and why it should connect to the carb. Now I have a hose coming from the driver's side head cover, it joins with a hose coming from the other cover and the resulting hose enters the air cleaner plate. I have no idea whether this is wrong and how.
Can someone please explain how and why the PCV has to connect to the carb?
@FlippindaBird One of the hard hoses coming from the back of the carb goes to the MAP, but I don't know about the other one. I think I have it too (it goes into the harness on the passenger side) and it's disconnected. i have no idea what it's for.
Can someone please explain how and why the PCV has to connect to the carb?
@FlippindaBird One of the hard hoses coming from the back of the carb goes to the MAP, but I don't know about the other one. I think I have it too (it goes into the harness on the passenger side) and it's disconnected. i have no idea what it's for.
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Re: EGR removed what vacuums do I need
sounds like a pretty good crankcase ventilation system to me, not quite stock but if its putting vacuum to both sides it cant be bad...
i wonder where that MAPS is located???
i wonder where that MAPS is located???
#17
Re: EGR removed what vacuums do I need
Firewall, driver side, right next to some relays. The inlet for the hose is pointing downwards.
Looks like this (from underneath):
There's one more looking EXACTLY like this one, but it's not a MAP sensor, but a barometric pressure sensor. It's supposed to be on the firewall again, but on the pass side, I think. Most importantly, it should not be connected to the carb with a hose. Its inlet is supposed to be exposed to atmospheric pressure. I don't have this one and I'm wondering if this would cause significant problems.
Looks like this (from underneath):
There's one more looking EXACTLY like this one, but it's not a MAP sensor, but a barometric pressure sensor. It's supposed to be on the firewall again, but on the pass side, I think. Most importantly, it should not be connected to the carb with a hose. Its inlet is supposed to be exposed to atmospheric pressure. I don't have this one and I'm wondering if this would cause significant problems.
#18
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Re: EGR removed what vacuums do I need
good stuff i will look for that when i get back home
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