83 engine vacuum line locations

[mtmtntop]

two questions today. i checked timing (ok) and was going to check dwell but was puzzled. a dwell tach gets hooked to the distributor side of the ignition coil..., which in this case is inside the distributor cap, i think. how do you check the dwell on this motor (3A).
second question relates to vacuum lines. i downloaded a diagram which helped me sort out the 3 lines to the distributor but its not the same as my car when looking at the hoses coming from the passenger fender well. the diagram must be for a different year. the car is running like a vacuum line is off. i did find one line without a home and can't see where it goes. i've attached a picture. in question is the hose with yellow on it, and (hard to see) the 2 hoses that are below it
download/file.php?mode=view&id=14853&si ... 527a1e840e
does anyone have a link to a diagram for routing the engine compartment vacuum lines?

[dlb]

I've heard of 'dwell' but don't actually know what it is. I don't think it's something you can check, or need to check, on this car.

Have you checked the FSM? It has lots of info on vacuum lines in the emissions section. You can download it here:

viewtopic.php?f=2&t=8103

[mtmtntop]

thanks for that link. it turns out that is the diagram i already have. and i have an 85 to use as a reference. the problem is there were changes between the 2 years. i have a fsm that goes from 80-84 and there isn't even an "emissions" section.

re the dwell. well, i guess my age is showing. before electronic ignition, you used a dwell tach to check the point gap without a feeler gauge and it was way more accurate. some distributor caps (not toyota) even had a little opening to put an allen wrench in to adjust the point gap while it was running . i went back to my fsm and did find a discussion of where to hook up the meter, if you did not have a breakerless distributor. i have to go take mine apart and find out which type i have. my fsm says the gap should be .018. and that would be 52 +- 3degrees on the dwell tach. apparently i can hook up the dwell tach and check point gap with cap off just cranking the motor.

[rer233]

I've never seen a USA spec Tercel wagon with points-type ignition. Does your car have an external ignition coil, or is it built into the distributor? If it's part of the distributor you definitely don't have points, and the dwell meter is pretty much useless.

Good Luck!

[Paul]

I recall the days of breaker points and measuring dwell; the amount of time the points were closed allowing the coil to charge. The 85 FSM warns of grounding coils leads and possibly damaging the igniter or ignition coil, so be careful here.
Running like a vacuum line is off could be a number of things. What is it doing? Remember too that these old vacuum advance units can fail and leak. When adjusting the timing, the FSM notes a change when you reconnect the vacuum line. Verifying the diaphragms hold vacuum with a hand pump might help sort things out.

[dlb]

Verifying the diaphragms hold vacuum with a hand pump might help sort things out.

I agree with confirming all diaphragms hold vacuum, but I just suck on the hoses to them with my mouth. I'm a filthy hick, it's true, but it works.