I have an electronically controlled Quadrajet on an 87 LG4 motor.

I've got a lot of cracked vacuum lines and I was wondering if anyone knew what sizes they were so I can replace them.

Any help is appreciated.

 

Just get a package of each size. It's cheap enough.

http://www.oreillyauto.com/site/c/se...brand=Prestone

 

There's no O'Reilly near me. Are those definitely the three sizes on the carb?

 

Any good auto store will help you with the right size hose. take a piece with you.

 

5/32 and 7/32 is what most of it is. Bigger lines like the PCV and power brake booster line are 3/8". Agreed with above- get a spool of each. It's just handy stuff to have around the garage. You'll use it more than you might imagine once you have plenty on hand.

Some of the lines on these cars is the small diameter "plastic" line. Beware of that stuff- it can look good at a quick glance, but you won't know it's condition until you bend it. If you see cracks on the outside of the bend, it's shot. If you find it's bad, you should consider replacing the entire run, which you can do with regular vacuum line. Even though the diameter of the plastic line is small, the fittings it hooks up to on either end are usually a common vacuum line size. It's heat that kills those old plastic lines so the stuff under the hood is likely in a lot worse shape than, say, the stuff that runs the HVAC servos under the dash.

 

Do I really need all these lines? I don't have the emissions stuff on the car any more. It looks like the MAP sensor isn't even hooked up right now either.

 

on a 85 in ny you can get rid of everything if you want, you have to get historic insurance and registration then you only are required to have safety inspection. but, its all or nothing. you cant run the original carb, dist, trans, without the pcm having ALL its inputs. you can search the sticky or google to convert the 700r4 to lockup. the carb needs to be a non electronic one either older qjet or aftermarket. the dist has to be a 70s vacuum advance also or aftermarket. and if you get rid of the pcm and all that wiring you have to change the fuel pump wiring a bit. if you are going to do all this let me know i can be more specific.

 

Take a few pieces to autozone or advance auto they sell it by the foot and it is cheap.

 

jwfirebird. My car was a 2.8 swap to a 305 and I'm not sure any of that stuff even works. My canister basically has one line in it if I remember correctly. The fuel pump is mechanical although the original pump is probably still in the tank.

I was more looking to know about all the stuff hooked up to the carb at the moment and whether I needed to keep all that.

 

its a mpfi 2.8 same as my 87 was, i blew up one and put another in but the third time i put a 86 305 in mine so i should be able to help if i can remember everything.

the fuel; you need to decide if you want to use the mechanical pump or the intank one(you cant use both). if you want the mechanical you have to bypass the intank unit by removing the sender. there is a sticky in this section about it. i just rewired the intank unit, you dont have to remove the tank, this was the better option for me since the straps have not been touched since they were put in from the factory. you have to get a return regulator and run a line to the carb.

the engine is not going to run properly only half hooked up, the carb varies and the timing is all controlled by the pcm and its inputs from the billion tubes and sensors. so i just ripped all that junk off, wiring, basically everything on the passenger side harness. you have to get a non computer carb and hei though in order to run this way. personally i would just get a holley 5-600cfm range vs Carb that will fit on a spread bore intake or you can change the intake to like a performer and get a squarebore intake and carb like a 4150 holley.

the ignition can be any type of vacuum advance hei, depending how much you want to spend. a junk yard base with new tune up stuff will likely be fine or a aftermarket one.

the trans wont lock with out doing whatever conversion you choose. alot of people just wire a switch, seems very simple this way.

i put headers on it, to clean up the air tubes and junk. all other ports and that can be blocked off, except if you want to retain the hvac, it has a vacuum feed i think, dont really remember i tossed mine.

 

it is alot of work but when you get sick of the 305 not being any more powerful than the 2.8 you pulled out , everything will already be done to drop a 400hp crate engine in. thats what i did. the headers, intake, everything is the same. the carb though needs to be a 750, so i wouldnt go nuts on the cost of a small one for the 305. my little 2.8 pump and holley regulator is still going strong even feeding that engine for a long time.