91 Corolla spark issue

Hi all,

1991 corolla wagon. 1.6, 5 speed. It’s my wife’s vehicle and it broke down on her about 5 miles down the road yesterday. Sputtered out in 5th gear, lost power briefly. Now wont start. Cranking sounds normal just cant get it started. First I tested for spark - no spark at any of the plugs. All plugs, wires, rotor and cap are new as of 1/19/19. Opened up the cap all contacts look good. Nothing obvious. Next , i grounded a wire to the battery and put the other end up close to what I assume is the coil, and got a spark from that. Could this just be a faulty cap or rotor? Am I correct in thinking that the distributor itself is ruled out being that the coil sparks? Appreciate any info!

Tim

There are many possibilities so a mechanic will have to do some testing. Don’t poke wires where they don’t belong. If your coil has an igniter under it, the price could be over $300. You want to be sure that you only pay for what you need.

Thanks for the reply! Care to elaborate on the possibilities? Appointment with mechanic is 2 weeks out. My wife is pregnant and needs the car asap. Can’t hurt to run some tests to rule some things out.

There may be a pickup coil (signal generator) in the distributor. It does what points did in old style distributors: detects when a lobe on the shaft comes into position to signal the coil to fire a spark. It is heat sensitive and can fail hot and eventually fail altogether. You may also have an ignitor in the ignition system, but if no spark, I’d first suspect the pickup coil / signal generator. One failed on my 1979 Toyota truck. The part was under $100, as I recall, and the shop charged about the same to diagnose and replace it. Good luck! I think signal generator is the term used in the Toyota manual.

Thanks you

Toyota’s of this vintage are notorious for bad ignitors in the distributor and you have the classic symptoms. If you have over 200k, I would recommend that you replace the whole distributor though. The shaft bearing in hte distributor is just a hole in the housing and when it wears out, there is no repair. The shaft will wobble, causing a variation in the distance between the ignitor and the reluctor, which will cause an intermittent spark.

If the shaft bearing is bad, the spark is intermittent, when it goes suddenly like yours did, the ignitor is bad. But I had a case like yours and a month or two after replacing the ignitor, the spark became intermittent and I ended up replacing the whole distributor. But that car was approaching 300k miles.

Thanks a lot. Leaning toward distributor replacement

If there’s no radial play in the dist shaft, it does not need to be replaced. But a new or reconditioned dist may (or should) have a new signal generator.

Is the ignitor available separately? I couldn’t find it on Rockauto, just an ‘ignition control module’ for $300 or so.

How do we know the timing belt didn’t snap? If the camshaft isn’t turning, neither is the distributor shaft.

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Good point - does the distributor rotor turn while cranking the engine?

It was the freaking rotor. 6 months old. Popped a new one in fired right up runs great. 2nd time I’ve had a part fail me from my mechanic and left me stranded. This time my pregnant wife stranded in smokey hot southern oregon. I called him as a regular customer to see if I could have it towed there. He says theres no room and can’t get me in for 2 weeks. Time for new mechanic. Thank you everyone

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It’s a moot point now since it turned out to be the rotor, but ignitor is not the Toyota name for this item, it’s just what most Toyota people call it. I forget the actual name.

Well good to hear you got it running but I wonder if the rotor was really the issue. I wonder if something else was causing the issue since a rotor is just a simple device. If you still have the old one it would be interesting to see if putting it back in duplicates the problem. For curious minds that need to know.

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@Cougar I will try that when she gets home. The rotor was cheap. I could visibly see inconsistencies in manufacturing on it. I held it up to the same one in the store and it looked inconsistent, so I bought a different one. 3 days of trying everything…When I popped the new one in, there was zero hesitation, it started as good as a car can start. Before the tune up in January, it would always start but would take a couple tries. When I picked it up from tune up, it still had that same symptom which I found odd. My guess is that the rotor was compromised from the get go. I am no expert, but I still think because I was getting good spark to the coil, it then could have only been cap, rotor, wires, plugs. I inspected those 4 things closely and decided something about the rotor did not look right to me.

It just seems so unlikely that a rotor was the cause of the trouble, but I know they can cause problems, and ‘strange stuff’ does really happen at times.

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I have a 92 Corolla w 4afe engine. As part of a routine tune-up, the ignition rotor can sometimes be awkward to remove and install. It sometimes sticks on the dist shaft. Perhaps that’s related. I always thoroughly clean the rotor mounting surfaces when installing a new rotor for this problem. I also apply a little moly-lube, just a wee bit, so it won’t get stuck the next time.

I’ve also had a problem being given the incorrect rotor from the parts store. Ask your shop/parts store to double check it’s actually the correct rotor for the engine, and matches the existing one. I normally don’t replace the rotor unless I’m also replacing the cap and spark plug wires.

As mentioned above, not a good idea to test for spark using the method you described above. The coil and ignition module (igniter) are inside the distributor cap, and are electrically connected to the engine computer. Sparking using that method could conceivably damage the engine computer, which is not something you want. I use a spare plug to test for sparks during cranking. Next, I test the power supply voltages to the igniter. Beyond that I use an o’scope to check for the pulses that fire the igniter.

I’ve had the same issue on 90’s Hondas. It doesn’t take much of a problem to cause the spark to be weak or nonexistant post-distributor.

Hey OP, after you get done testing rotors, be sure to put a little breakable threadlocker on the rotor set screw. Sometimes they’ll back out, and when that happens they get flung around inside the distributor by the rotor and cause lots of damage.

Had it happen to me once. I had just done a “tune up” so the old rotor was still in the car. The new rotor only lasted about 4 miles and the motor just stopped running, no spark on the spark plug wires but good spark on the coil wire. Put old rotor back in and left it there until the next tune up. IIRC 79 Dodge Colt, still used points.

About the only thing that I can think of why a rotor would not work is the connection between it and the center coil lead is faulty.