welcome, ilovetrash. yet another great username. i do too, if by trash you mean wicked old beaters that are better than any new cars. i like the graphics on your car. did you do them?
Ilovetrash wrote:Is it the vacuum seal? If so, what are the necessary steps to getting to the source of the problem.
what vacuum seal are you talking about? there are many sources of vacuum and many seals so you need to be specific.
Ilovetrash wrote:Oh yeah, one more thing: The car came with the 1984-19?? repair manual. Should I buy the 1983 manual or should I just stick with this one?
if it's a factory service manual, like the one available here
https://tercel4wd.com/forums/viewtopic.php?f=2&t=8103
it will be fine. there were very few changes to 4wd tercels over their production run and most of the changes were only cosmetic.
Ilovetrash wrote:I hope I'm not incapable of finding the problem. Out here in New Mexico every mechanic has told me: It's old, it'll do that. ! This is frustrating, because I know that something is wrong
do not listen to those mechanics. 'old' is not synonymous with 'malfunctioning,' and you don't want anyone who has that kind of "good enough" attitude working on your car anyway. who knows what else will be "good enough" for them? i find it best to work on my own stuff since i care about it more than anyone else will.
on to your issue. it's likely something very simple and easy to repair. tracking it down is the hard part but even that is not so hard. first, i would check the air filter since you didn't mention that. next, i would check the carb float level. to do this, park on level ground, remove the air filter housing, and look through the sight glass on the front of the carb. rock the car a little bit if you can't tell where the fuel level is. the fuel level should be between the two points on the window. if it's really low, you could have the symptoms you describe but i suspect you would also experience slight bucking on cornering as well. if the fuel level is fine, i would continue checking for vacuum leaks. you mentioned that all the vacuum hoses are connected, but you need to verify that they are hooked up correctly and that all the things they are connected to are not leaking. to do this, look on the underside of your hood. there should be a sticker with the vacuum diagram. if not, you need to confirm which emissions set up you have and use the appropriate vacuum diagram found in the FSM. if your car is originally from new mexico, it's probably the federal model, in which case you can use this colour-coded diagram.
https://tercel4wd.com/forums/viewtopic.php?f=7&t=2810
once you have confirmed all the vacuum lines are routed correctly, you can then begin testing the various vacuum components. test the PCV using the test in the FSM. for all the various diaphragms (TP, choke opener, choke breaker, and vacuum advance), put a clean hose on each one and suck. if you can suck air through, the diaphragm is broken and needs to be disconnected and plugged until you can replace it. otherwise they act as vacuum leaks because the engine is able to suck air through them.
i would also check your EGR. over time, carbon buildup stops the EGR valve from completely sealing and you wind up with a vacuum leak of exhaust straight into the intake manifold. completely disable the EGR is a small project though so i would test only after testing the other easier things. to disable the EGR, you must disconnect and plug the vacuum lines that go to it, then undo the big nut and bolt that fasten the exhaust tube to the EGR (be careful not to strip them!), get a new 20x1.50mm bolt to plug the exhaust manifold, and one to plug the EGR itself. most people wind up removing the EGR altogether for another mod but i just realized that you can leave it in place if you simply plug the hole in it with a big bolt, like on the exhaust manifold end of the tube.
try those things and let us know how it goes.