A little lost please help
Thread Starter
Intermediate
Joined: Aug 2003
Posts: 48
Likes: 0
From: Oklahoma City Ok
A little lost please help
I have been working on my 87 vette for about 3 months.It blew a headgasket so i decide to do it myself so in the process I decided to ditch the egr and the air pump and all the smog stuff.Now im almost done but have some things that im not sure about so if someone could help me it would be much appreciated.There is a vacumm port on the driver side of the under side of the throttle body do I need it or block it off.And there is 3 ports on the passenger side of the throttle body.I know one of them is the coolant line which i will be bypassing but are the other 2 vacuum lines do I need them or can I block them off .And on the driver side middle way down on the intake between 2 injectors is some sort of port that was hooked to part of the emissions can I block that off.And I have 3 pigtails left after I got ride of the air deverter thing and the egr switch do I just tie them back are do I have 1 to many.This car is eating my lunch its not as simple as my 68 vette.I would appreciate any additional info someone could share sorry my post is so long I think I will get this car figured out someday.
Instructor
Joined: Aug 2003
Posts: 163
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From: Glendale Az
Re: A little lost please help (68vetteguy)
Ok, Throttle body side is vacuum. Goes to egr solenoid and charcoal canister. Will not hurt to plug off. On the pass side one is a vent to go to the valve cover, one is the heater hose, and one is also vacuum to the canister. The canister vacuum went under the throttle body, behind the alt and over to the canister. The engine needs a vent, otherwise you can block them all off. Some people use a vented breather cap. Won't pass emissions in most states. Driver side port is pcv valve. Goes to drivers valve cover. You will need that. Should only be two connectors to the dirverter valve. Each has two pins. I believe (without a picture) that the extra is for the cold start sensor located in the front of the intake manifold. Of course, it could also be for the coolant temp sensor or the mass air flow sensor. How many pins or wire colors? Hoped this helped. Have fun... :chevy
Le Mans Master
Joined: Jul 2001
Posts: 8,183
Likes: 3
From: Santa Maria, CA
Re: A little lost please help (68vetteguy)
The one port under the left side of the TB is where the gas vapors stored in the charcoal cannister get sucked in when signaled to do so by the ecm. This is called purge duty cycle. Usually happens upon start up and part throttle conditions. It serves to keep those hydro carbons out of the air and tries to put them thru the combustion process again.
The driver side port you mention is the big one that goes to the valve cover right? That 's the same story.
The driver side port you mention is the big one that goes to the valve cover right? That 's the same story.
Thread Starter
Intermediate
Joined: Aug 2003
Posts: 48
Likes: 0
From: Oklahoma City Ok
Re: A little lost please help (69vetteracer)
Thanks alot that explains a bunch I forgot one of those pigtails goes to the maf sensor.I figured I was missiing some stuff cause all the empty holes.Hopefully I can make this car run again thanks for your help.
