I know this probalby sounds stupid but i'm still learning all the parts of my car and trying to figure out why it won't stay running. when I bought the car some of the smog system was already disconnected. right now a check valve is broke on passenger side and the TVS thermal vacuum switch, I've been told, next to the engine coolant sensor on the termostat, is broke at the top so the rubber connector won't hook back up to it. do I need this? I know it has someting to do with the egr. also,do I have to have the egr? the air switching valve i think is disconnected as well.

 

They aren't "needed", but if non-functioning, the vacuum sources to them should be plugged.

 

Wow. Is the CEL on?

 

It won't be for those items (ask me how I know. . .).

 

Nah, from the sounds of it I don't have to!

 

thanks! would you happen to hace any clue why my car runs like crap, low rpms, puts out gray smoke when it starts. i have to hold the gas to keep it from dying. shakes also. after a minute it sounds and runs great until15 minutes then stalls whenslowing down or stopping and hard to start back if it satrts back?i'm just really puzzled

 

the computer controlled carb is partially regulated by that temp sensor on the neck of the thermostat housing. It changes fuel mixture based on engine temp. That and if you have any vacuum lines running open from anywhere like the smog stuff that will cause it to do something similar to that.

Id recommend going over everything line by line and make sure you can find where all the vac lines go and they are all being used and if not they are plugged. Also fix that sensor you can pick up the pigtail for it at most auto part stores for like 2 bucks. Just ask for the coolant temp sensor pigtail or wiring harness for your engine.

Id imagine if you do those 2 things you will be tons happier with your ride. And the smog stuff does nothing of any use but strain the engine more and cause losses of power by reusing old combustion by products. Good for the environment but bad for power/mileage.

Wesdog

 

Th only "power robbing" emission equipment might be the air injection pump. It might sap a whole 1-2HP at peak RPM, unless the pump is damaged. The rest of the components are almost completely passive.

The EGR is only supposed to be open when the engine is at operating temperature, at a moderate RPM, and at light-load, high-vacuum cruise. At WOT (when you want to make power) the EGR should be fully closed. That is if everything is working properly. If there are partial disconnections, reconnections, bypasses, and failed components, that isn't necessarily the case.

The EVAP and its purge system require no engine power, won't lower performance unless there are problems. And it can improve fuel mileage noticably in warmer weather. The bad part is that the canister itself can take up space you might use for other useful things, like tubocharger intercoolers, etc.

What year/engine are we asking about? Usually, there is a VECI label on the radiator support or underside of the hood showing the proper line routing and connections.

 

it's a 1984 305 v8 code"G" with carb. I did get engine light to work again. has code 13. the o2 sensor is about 7 months old but the spark plugs are a little black. they are about 2 months old. I also noticed that even in park when I turn the wheel the rpm's drop and if i turn it all the way the engine dies. ???