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Here's my quandary I removed the convoluted anti emissions gear from my GN wagon. the old vacuum lines were everywhere how do you strip these systems back to basics? I installed a Weber in my scorp and trial and error was the way I got it to run. I'm not even sure its an optimum set up but since I don't really get how the system works and what weird U.F.O. shaped things actually do, close enough has made do. When I asked my old man who's a bit of a dodgy back yarder himself his reply was.
"does it work?"..... "yeah"......"if you disconnect any of the lines, does it run crap or not at all?........"yeah"........"well its set up right then!"
Diagrams or photos would rock my world and if you could touch upon both astron 1 and 2 that would be tops.
Thanks in advance. Tubby

The weird UFO shaped thing (EGR valve) steals some vacuum from the inlet manifold to open a piston inside of the valve body. When it actuates (opens) it allows some of the exhaust gas from #3 exhaust port to be sucked back into the inlet manifold in an attempt to burn some of the air/fuel mixture that hasn't combusted the first time around. Well, what it actually does is stuff your idle and rob your engine of tuneability. And in a car that's twenty years old it's already blocked with carbon through the gas port or the EGR valve piston is frozen from being carboned up too- it probably doesn't work anyway (like the one I've been trying to pretty up in my moments of boredom...) Does the GN have the EGR running off a big pipe from the exhaust manifold too? Get an exhaust manifold from an older siggie and swap it if it does. This will make the set up a lot tidier too look at and is better than cutting the pipe and bending it over.

The biggest problem with removing all of the pollution gear is the potential to have your car knocked back on rego inspections (NSW is bad for this). I've been told that all it has to do is look like it's attached so as not to draw attention that it's disconnected (as they don't actually test to see if it is working). One way to get around it is to block the vacuum lines up and reconnect them. That way they appear to be as they came from the factory. As geezer101 stated

geezer101 wrote:in a car that's twenty years old it's already blocked with carbon through the gas port or the EGR valve piston is frozen from being carboned up too- it probably doesn't work anyway

not much work if any is needed to stop that from working.
If a weber is fitted then that is a little more difficult to hide, you could do as LCcoop did to my hatch before I bought it, he modified a factory aircleaner to fit the weber. It all looks stock to the untrained eye when you pop the bonnet.
I know other states are more relaxed with rego inspections then NSW, but the fact still remains, if you have a car newer then 1/1/1976 emission laws apply, and if you modify it you are potentially opening yourself up for a defect. The better you can hide any mods the better for you in the long run (unless of course you have engineers certs for the mods).

I have been knocked back for rego before on my old 84 VK Commodore. I removed the airpump to fit extractors, it was seized and did nothing anyway. All the air pump does is pump clean atmospheric air into the exhaust so that when it gets to the end of the exhaust it makes it seem like the car is better on the environment, WHAT A LOAD OF CRAP. I imagine this is the reason they then fitted the Nissan motor to the VL Commodore, to get it past the emissions testing, as the Holden 202 was way past it's use by date for being environmentally friendly

tubby wrote:I'm not even sure its an optimum set up but since I don't really get how the system works

So in summary, I would leave everything hooked up and connected, but just block the hoses up.

Dave...

I just bought extractors for the GN so no bendy pipe for me. plus since I have made my station wagon into a panel van with a welder a few vacuum lines removed isn't gonna get me passed. In SA so no rego issues either. So basically block them all? Isn't there ones on the distributor to advance the timing and one to up the idle with the air con on?

tubby wrote:So basically block them all? Isn't there ones on the distributor to advance the timing and one to up the idle with the air con on?

I was only referring to emission control hoses, not ones that are essential to making your car run properly. I should have explained that.
All this does is return the motor and it's emissions to that of a car pre 76. So not choked up by having to reburn it's own exhaust gases

Basically, as emissions rules tightened up, carburetor'd cars got more and more things done to them to try to get them past the testing that new cars were subjected to at the time. To my knowledge it was an exhaust probe. So the method Holden used of diluting the exhaust with fresh air would improve the emission levels at the exhaust, but as far as the car being any more efficient or better for the environment, it did absolutely nothing as the exhaust gases were exactly the same.

Dave...

The exhaust probe is still used today, lol
I had to use it when complying imports

OK explain how I can simplify this.......

tubby wrote:OK explain how I can simplify this.......

Convert to EFI.

If you are going to put all the emissions stuff back on to keep it legal, then the whole lot will have to go back as it is shown there. EFI would simplify the emissions problem.

Oh Mr Hart, what a mess!

Even if the scan was in focus I'd be scratching my head at this and wondering where the hell I'd start? there's a couple of lines that don't do beans (like the one going to a vacuum actuator mounted to the firewall- it tells a pretty light on the dash that you need to drive like grandma and save fuel) bottom right of diagram. Or the thermal valve (gadget screwed into the coolant gallery below the thermostat housing- what the hell does this thing do? On this diagram it looks like it controls the vacuum line to secondary actuator (on the carby)so it looks like you should be able to bypass that and run it off direct vacuum from an outlet on the carby. If you're not using a factory air cleaner the line to the cold start butterfly can be blocked off. The rest of this stuff-

Cottees wrote:

tubby wrote:OK explain how I can simplify this.......

Convert to EFI.

If you are going to put all the emissions stuff back on to keep it legal, then the whole lot will have to go back as it is shown there. EFI would simplify the emissions problem.

yeah simplify my vacuum lines by complicating my wiring? not really the fix I was after. as for legality, meh. basically just want to know which one needs to go to the dizzy all the rest will be discarded.

so... after market extractors and a webber?

got any pics of your current set up?






if you really just wanna run the dizzy by its self without any emission stuff you could plug everything up like that using an astron 1 dizzy, id keep the charcoal canister functional but thats just me also ignore the circled thing.

Thats how I set it up in the end. Things got simpler when I removed the intake manifold and realized it was it was knackered then replaced with gk one with less vacuum lines. cheers anyhoo.