Simplifying Carb Connections

[pantah]

I live in an area with no smog inspections and the temperature rarely goes below 65F, and NO smog inspections. I think my TSVS gizmo is funky and may also have a vacuum leak somewhere. I would like to disconnect as many vacuum lines as possible and other extraneous things. Also want to convert to a manual choke, as the auto choke doesn't work. I know that the ones for the vac advance and power brake booster are needed for sure. Any ideas?

[dlb]

your vacuum leaks may not be related to the vacuum hoses. the leaks could be due to loose carb mounting nuts, loose intake manifold bolts, a crack in the intake manifold, wear in the throttle shaft hole of the carb...i would find the leaks and deal with them first before disconnecting everything else. other guys have tried disconnecting most of the vacuum stuff and have said it ran crappy.

also depends on what emissions controls your car comes with. our manual trans canadian ones have no ECU which makes it really simple, but both the federal and california spec tercels have ECU's controlling a few things. i have no idea what package yours came with in panama but if it has an o2 sensor, it also has an ECU. that will complicate de-smogging it a little bit.

[irowiki]

Sometimes the car runs worse after you start disconnecting things willy nilly, so beware!

[pantah]

The car was originally US spec automatic from New Mexico. It has an ECU. I had previously checked for vacuum leaks in the hoses, diaphragm, bolts etc. Maybe I missed something. I can leave the essential stuff connected, just need to know what it is. Trying to avoid buying a TSVS or whatever it is called.

[irowiki]

What makes you suspect the TVSV?

[Petros]

the fuel system is designed to have all those vac operated systems working, if you disable them it will make drivablity troublesome, and could harm your fuel economy.

There are many than can be disabled with minimal effect, but you have to do it properly, not just yanking them out and capping off the lines. if you do that it will run like crap. It will actually run best and get the best fuel econmy if everything is working properly. If you can not get replacement parts than you can usually by pass the bad parts so you can drive it without too many issues.

The best thing to do is to go through the fuel system and emission control system part of the manual and understand how each system works. Than when and if you disable the system you can do it in such a way that it will still drive okay. You can remove the EGR system, and cap off all of the holes and connections, without any issues. You can also cap off the Auxilary Acceleration pump (AAP) if it is not working properly with little effect after it warms up. It helps prevent flat spots and slow acceleration when the engine is cold, but once warm it is not supposed to be affecting how the engine runs. If the AAP leaks, or the TVSV is not working, than it is not doing anything anyway, and actually harming fuel economy, so you can cap it off.

You have to make evaluations of each system to know what needs to be done to cap or by pass the system. The vacuum advance on the carb, if working (test it per the manual), should be left operational. If the TVSV is not working you by pass it by having the vac advance ported to manifold vacuum directly. If the vac advance is ruptured and not working just cap it off at both ends, it will not effect the drivability, though it might slightly effect the fuel economy in stead state cruising, such as on hwy trips at constant speeds. But it will not harm anything to drive without it.

there is also that device on the right side of the engine compartment on the fender (next to the radiator and windsheild resivoir) I think called the EVBC or something, it controls the fuel mixture by bleeding air under the carb (to lean the mixture) at mid rpm range. But if it is not working properly the car will surge and have flat spots at mid rpm, if you disable it (disconnect it) it will run okay but the car will get really poor fuel economy. I am not sure if there is a good way to preserve the fuel economy, have it run well, and also have this device disabled. Again something you will have to study and see if it can be by passed.

[pantah]

Petros (and others), thanks for all your help, appreciated. I have studied the manual and have some familiarity with these components. This is the latest model car I have ever owned and it is kind of overwhelming compared to my previous vehicles.

[xirdneh]

the TVSV is testable per Factory Service Manual
they can often be fixed if you have some mechanical skills
there is a write up on how to do it in the "Repair Guides"

[Petros]

government requirements, emissions laws and other issues made the cars get more complex. Each of the systems in not so difficult to understand, just them them one at a time. No reason to be overwhelmed, which is easy to do when you look at the mass of vac lines, electrical components and other gadgets all at once. Each system is rather simple, it is just that there are a lot of them so it is easy to be intimidated, and just want to rip it all out. but do not do that, it will run like crap. Best fix it properly and it will run well for you.