1977 Corolla ignition issues

[Raggleflaggle]

Trying to revive this old wagon, hasn't run in at least five years. getting a no spark condition.

 

NEW

points+condenser

Cap+rotor

Plugs+wires

Coil+ballast

 

New coil tests @ 1.8 and 9.97.

 

The points open and close properly as far as i can tell.

 

The coil is getting power.

 

Motor is grounded.

 

Plugs are gapped correctly.

 

Only mystery item is the ignition box that is attached to the coil. Yellow wire to output of ballast, black wire to negative on coil. Mystery red wire that goes nowhere.

 

Pics will be posted asap

[Raggleflaggle]

[Raggleflaggle]

The mystery wire -appears- to go to the points. The PO had it connected to the - coil connection assumably trying to bypass the box. I have tried both ways, neither worked. The box has what looks like a secondary resistor underneath the primary resistor. Hot start or cold start assist? Some situation where spark needs adjusted that doesn't correlate with vaccum?

[Raggleflaggle]

[Skib]

Iv got a 76 with a 2TC Iv been working on. I can take a look how that's wired tomorrow. 

[datzenmike]

1 hour ago, Raggleflaggle said:

Trying to revive this old wagon, hasn't run in at least five years. getting a no spark condition.

 

NEW

points+condenser

Cap+rotor

Plugs+wires

Coil+ballast

 

New coil tests @ 1.8 and 9.97.

 

The points open and close properly as far as i can tell.

 

The coil is getting power.

 

Motor is grounded.

 

Plugs are gapped correctly.

 

Only mystery item is the ignition box that is attached to the coil. Yellow wire to output of ballast, black wire to negative on coil. Mystery red wire that goes nowhere.

 

Pics will be posted asap

 

 You haven't said it, but can I assume that there is no spark and this is the problem? How are you testing for spark??? What happens if you pull the coil wire off the distributor cap, put an old spark plug in the end and then hold it against the grounded head while someone tries to start the engine???? Got spark?

 

If this was a Datsun I would tell the owner to perhaps invest in a FSM factory service manual, NOT a Haynes, but one from Toyota and for that exact model and year. One with all the wiring diagrams, maintenance, brake servicing, carburetor, ignition, drive train, fill quantities, what lubrication to use, troubleshooting etc. 

[Raggleflaggle]

That is exactly how i'm testing. Tried with the #1 plug wire and the coil lead. No difference.

 

[Raggleflaggle]

I'd appriciate the hell outta that. Car came to me not running, so i don't even know how a running 2tc is wired.

[datzenmike]

To eliminate the coil as a cause. Make a ground wire, turn ignition on and briefly touch to the coil negative side. You should get a spark. Yes??

 

 

A handy thing to have is a $5 test lamp...

 

 

It will tell you if you have power at the coil positive terminal.

[Raggleflaggle]

I'll likely have to dig out the book for it, i think i have a more generic one thst covers that generation of car/motor.

[Raggleflaggle]

Just put ground to neg. On coil. Got sparks.

[Raggleflaggle]

I have power at coil, used a multimeter. I'm thinking something to do with the points not telling the coil to fire? Dist. Has ground. Points are gapped at .017? Does that sound reasonable?

 

I don't have a spec for this particular engine. Still should generate a signal and have spark, right?

[Raggleflaggle]

This majigger is unplugged, no obvious connector in sight... it isn't actually connected to the coil or to the igniter box in any way. Unless i'm missing a piece.

[datzenmike]

23 minutes ago, Raggleflaggle said:

Just put ground to neg. On coil. Got sparks.

 

Then almost fixed. The last thing is the points. All they do is ground the coil and then open causing a spark. You need the points to close and a gap (usually 0.018" to 0.022") when they open. Coil negative foes to the points. The other thing is the distributor must be grounded. Make sure it's bolted down.

[Raggleflaggle]

It has new points, maybe i've gapped them wrong? I just youtube'd it, and gapped them at .017. I guess it should be more. Would still spark even if the gap is off a little, yeah? They close fully when not engaged by the cam in the distributor. Dist. Body is grounded as is the little wire at the end of the points.

Edited Monday at 05:06 AM by Raggleflaggle

[datzenmike]

As long as they close and make contact and then open and break contact they will work. Did you set the gap with the points block on the top of the distributor cam? A test light connected to 12v and the probe on the points should light when the points close (grounded) and darken when they open. 

[Raggleflaggle]

Not sure if this doodle shows it well enough, but this is hoe i have.

[datzenmike]

That's the correct way.

 

So follow the coil negative wire. It should go to the distributor and connect to the points. The points are grounded so when closed the coil negative should be at ground.

[Raggleflaggle]

It does, but goes to the igniter(?) Box on top of the coil first, then to the negative. If i put the points directly to the neg. Coil connection, that will be how the car was when it came in. Suggesting a bad ignition box. But at least that way it should have spark.

Still no idea what the little side box that connects to nothing does. Must not be essential?

[datzenmike]

I has electronic ignition???? There's nothing to fix. If it's the cause you'll need a new one.

[Raggleflaggle]

Igniter isn't right word i guess. Its the rusty box that sits on top of the coil in the pictures. It connects to both the ballasts, the points in the dist, and the neg. On the coil.

Kinda figured it was something that was important to a points system that isn't present on newer ignition systems.

 

I'll just have to go get an FSM to know for sure.

[Raggleflaggle]

In case anyone needs to know, the little box has some sort of alternate internal grounding path or something that was preventing the points from properly interrupting/suppying ground. Not sure if faulty or by design. Ended up just putting coil - to the points output. Motor runs fine now.

 

Pretty sure this bypasses both ballasts fwiw. 🤷‍♂️

[datzenmike]

This does not have dual points in it?

 

Pretty sure you need a ballast in line with the points when running. Datsuns have 12v directly to the coil around the ballast, in start mode but when running, power is fed through the ballast. This give full hotter spark during start but cuts it back for driving. Too much voltage will draw too much current through the points and burn them up, also the coil will get hot. 

 

Yeah, get the factory manual. 

[Raggleflaggle]

The box doesn't have any external connections, so it doesn't have a Start or Run position. I'm guessing it was supposed to be heat based in some way, as it doesn't have a vaccum port or aything else connected to it.

 

If i read your post right, i should be able to put the points that are currently on the - and connect them to the left terminal on this ballast(yellow wire), and that Should protect the points from additional wear.

Then just use a relay(?) that connects the coil - and the points directly when the key is in Start position?

[datzenmike]

See what the ignition switch does. On Datsuns the ON and START are 12 to the ballast which drops it to 8v? and that is on any time the ignition is on or stat. There is also a connection on a separate wire that is 12v only in START. This goes to the + side of the coil. During start the 12v from the START wire provide maximum volts to the coil for better starting, specially when the starter is cranking and drawing current. Once the engine starts the key returns to ON. The START signal ends and the volts are still there through the ballast. So there should be (or may be, I don't know old Toyotas) two wires from the ignition switch, one that has 12v in the ON and the START positions and another wire that is 12v only in the START position.