1990 Toyota Camry Ignition Coil Issues

Hello Everyone,

I have a 1990 Toyota Camry (V6 2.5L) station wagon. It has 109,000 miles on it. I have been having ignition coil issues. I have replaced the coil 3 times in the last year and the car died again last night. I am almost positive it is the coil yet again. Does anyone have any idea what might be causing the coil to continually burn out ? The replacement coils have been purchased from Advance Auto Parts. In an effort to provide as much information as possible (which may or may not be related) I am also having occasional (random) trouble starting. Sometimes I will turn the key and absolutely nothing happens–then I take the key out, let it sit for a few seconds and then it will start right up. Also the “Lights” light on the dashboard stays on all the time even when the lights are off. There are no other electrical issues that I can think of. In terms of other repairs I have made recently-- replaced the distributor about a year ago and the starter about 6 months ago.

The car has become unreliable because of the coil issues (the car had died completely twice while driving on the interstate). I am considering getting it running and selling it but I would ultimately like to keep it if I can find a solution to the issue.

Thanks in advance for any insight anyone may be able to provide.

-Scott

You need to measure the voltage going to the coil. Too much and/or too little can cause problems and “kill” the coil. It seems you have a number of electrical issues, perhaps the ignition switch is bad. Likely the electrical issues are related so if you find the cause for one, you might cure the others too.

I’m also suspect of the new distributor. Where did it come from? Is it properly matched to the car? Could there be something that got wired improperly with the installation of the new distributor.

If I am not wrong your car only has one coil right?? In other words every plug does not have its own coil pack?? Lets assume, one… If it keeps dyeing on you either you are getting cheap poor quality coils (you may want to spring for a new Toyota part), or the coil is overheating. I know on some cars if you dont put fresh dielectric grease on the bottom of the coil they over heat and die… Could that be the issue with yours? It could also be that there should be some kind of resistor on the power feed line that has burned out, sendint too much voltage to the coil and burning it out.

Coils are very basic, so for them to keep failing means you have another issue causing them to fail. So you are addressing the symptom and not the cause.

The burning up of the coils might be caused from a defective ignition module.

The ignition module functions in two modes. These are the start and run modes. When starting the engine the ignition module allows full battery voltage to the ignition coil. This ensures that there’s a hot enough spark when starting the engine cold when the fuel mixture is rich. Once the engine starts and the ignition switch moves to the run position, the ignition module switches to the run mode. The ignition module then steps the voltage down to the ignition coil. This is done because once the engine starts and the charging system comes on line the voltage from the alternator is too high for the ignition coil.

So the problem might be that the ignition module is failing to switch to the run mode once the engine starts, and higher voltage from the charging system is burning up the coils.

Tester

Thank you for your responses, everyone.

Uncle Turbo, The ignition switch is a possibility for sure. I agree that the symptoms are likely linked. The new distributor came from Rockauto. A friend who is a mechanic helped with the installation and I am confident (that between the two of us) that everything is wired correctly and I made sure that it is correctly matched to the car. The first coil actually died with the original distributor and I replaced the distributor as part of our attempts to fix that situation.

gsragtop, There is only one coil. The dielectric grease is a possibility. Not something that the repair manual instructed me to do with the installation–but still a possibility for sure. That is a good point about the resistor. I have also wondered about the quality of the replacement coils.

Tester, Great explanation. I have considered the control module and that may very well be the issue. The biggest problem for me if that is the issue is that is the part is $400.

Thanks again, everyone–for all of your ideas, explanations, and effort to help me with this situation.

Is this the distributor that is piggybacked onto the distributor? And are you sure that the coils you replace are actually bad? How did you test them?

cont

I would suspect the distributor might be your problem. I’m guessing that you got a remanufactured distributor. If so, I would check the shaft for any side to side play. You need to line up one of the vanes on the shaft with the line down the center of the ignitor, then place a 0.010 feeler gauge in the gap. Then push on the shaft to see if you can open up the gap, this is the only way to see if there is too much play.

Keith,

It is indeed a re-manufactured distributor. The first coil that failed I brought to the auto parts store to have it tested and it was bad. The replacement coils have had large obvious burn marks on them so I did not bother to have them tested. Thanks for the information on the distributor and how to check the shaft.

Thanks again.

If you are burning holes in them, then either the applied voltage is too high or you are experiencing a lot of misfires. Since you have the V6, I suspect that 3 of the plugs are really hard to get at and maybe haven’t been replaced, even though you might have paid for replacement.

When the primary of the coil is opened by the computer, the coil has to discharge. If it can’t find the normal path through the spark plug wires and the spark plug, then it arcs internally. a coil can withstand a few misfires, but if there are to many it will burn up. Large obvious burn marks indicates an open circuit somewhere in the discharge circuit, i.e. plugs, wires, distributor cap or rotor.

Keith,

Thanks for your replies and explanation. You are correct the 3 rear ones are very difficult to reach. I am thinking based on your explanation, which is great, that the distributor cap and rotor are probably not the issue–as this has happened with 2 different distributors & caps. I am thinking that you may have nailed it with the plugs/wires. My guess after your explanation is that here is likely an issue with one of the 3 rear ones. Thanks for all of your help with this. Is there a way to check the individual plus & wires? Of course I do not have all of the necessary swivels etc… to reach the rear plugs.

Thanks again.

-Scott

WOW good call @keith … I think if I remember right you have to remove the intake to get to the rear plugs as the plugs are underneath it… I know my first real car was my Mom’s ex-company car a 1990 Buick Century. I know as fact she paid to have the plugs done at least twice before I got it… The rears were original AC-delco worn out plugs, when I went to tune it up.