Hi Guys - I could use some help understanding some parts, and some Bubba-work... it's a mostly stock '81 with Cat and Air/Smog Pump deletes...

What's this green thing by the air filter with the 2 vac hoses attached to the underside of it? Should there be something attached to it besides the vac hoses?




Driver's side chopped and plugged hose - what did this go to? And that's my PCV valve that it's Y'd to, correct?




Passenger side chopped and plugged hose - what did this go to? Air/Smog Pump? And is that a coolant temperature sensor that it's Y'd to?




This big black box is my cruise control, correct? Just flopping around in the engine bay - surely this was originally mounted somewhere, no?




What are the Orange and Yellow connectors with 4 lines coming out the bottom? (3 of which run to nothing - with 1 line plugged and 2 lines Y'd together and it looks like someone chewed the end of the line off - LOL)








Thanks a ton in advance for any info. - you guys are great!

Ritch

 

that is a cruise control box but it's not the factory unit, for sure aftermarket.

the rest of it is related to the smog/emissions system.

 

Green sensor in the air cleaner housing is a temp sensor, for the air cleaner snorkle intake damper.

Here is a diagram of the vac lines to explain alot of your other issues:

http://peter.all-corvette.com/Corvette/IMG_2926.JPG

 

Thanks guys! Great diagram - very helpful!

 

So what is an EGR? What does it do? Do I need it, or is it unnecessary emissions crap?

And should the T'd line from the EGR selenoids be connected to the Carb? Or OK if they're just capped off?

Thanks again!

Ritch

 

Ritch

Your carb and engine operation are calibrated to the emission control devices, most of which operate under vacuum...or did before bubba elected to discount the value of those systems. Some states where emissions are checked, require those systems to be operational.

 

Your pic 1 is a temperature valve that switches vacuum to the flaps in your air cleaner snorkel. Cold and the flaps are closed. Hot and vacuum opens the flaps letting in cold air. If they are not getting vacuum they will be closed choking your engine of cool air

Your pic 2. Vacuum hose should go to the charcoal canister in the drivers side fendor, below the windshield washer fluid bottle. I included a pic of mine for reference




Your pic 3:vacuum hose should go to the AIR pump diverter. Do you have an air pump? Included a pic




Pic 4. Definitely not stock. The cruise control solenoid is in the drivers fender near the ww bottle. Also, that pipe that looks like a fuel Line does not belong there? Do you have any clue where it is coming from? (It looks like the vacuum tube coming from the back of the carb which is the vacuum for the power brake booster? See the pic I included later, is that hole in the carb plugged? It would be a huge vacuum leak. Where is the power brake vacuum coming from!

The hose is a check valve that should have a hose that comes from the AIR pump to blow air into the exhaust. It is missing, so you probably do not have an air pump. It should at least be plugged ( I might see a plug in the hose). There is an identical one on the other exhaust manifold

Pic5 6 7. The red and while thing are solenoid so the computer uses to control the egr valve. Included a pic for reference. Do you have a egr valve? I don't see it in the pics



A lot of bubbas tried to remove the emissions stuff thinking there would be an improvement in performance. In my experience all it does on an 81 is screw up the vacuum signals to the computer and make things worse. An 81 is limited in heads and exhaust and removing emissions did little or nothing (maybe even reduced) performance

Do you still have an ECM and a CCC or have they also been removed.( do you get a check engine light when you start the car? Does it flash when driving?). The distributor looks like a stock 81 which means it will need a working ECM or the car will be very sluggish

I included a couple of pics of the whole engine bay for reference

 

Hey wajulia - thanks so much for the feedback and the pics there - very helpful! (and nice to see what USED to be there - ha ha!) - I really appreciate your taking the time to do this...

ECM and CCC are still operational - looks like the AIR SMOG EGR CAT stuff is all gone (leaving behind a mess of plugged Vac lines, dangling connectors, etc.)...

So yea, I'm just thankful I've been able to getting it running as well as I've been able to (MUCH better than when I got it!) - just done the basics so far - plugs, wires, air filter, tranny and coolant flushes, oil change, vacuum checks and new lines, etc... next on the agenda is distributor cap, rotor, timing... (maybe this evening)

This site has been VERY helpful to me so far - learning new stuff every day! Thanks to all!

Ritch

 

Glad to be of help. The forum has helped me with so many issues, least I can do is to repay

Please look over my post again. I think I was editing it when you were reading it. I am sure that we can help to sort out how it should be set up with all that stuff missing. It is critical that there are no vacuum leaks if the 81 ECM is to work right

I am very concerned about that disconnected break vacuum line on the back of the carb. Is it plugged, where does the power brake vacuum come from?

 

Hey wajulia - ya lost me - I have so many disconnected lines in there I don't know which one you are referring to - which pic? which line? My brakes seem to be working fine (although my Brake Light IS on - but I think this is due to some air in the lines - I've already determined that it's NOT the switch - but again, brakes seem to work just fine)...

Thanks!

Ritch