Slacker87

iTrader: (1)

So here is the story 93 rx7 auto 100k miles rebuilt turbo, rebuilt trans. Car was running great then the starter failed, rebuilt the starter. Car ran fine for a few weeks. Drove it home one day and parked it the next time I started it maybe a day or two later the car was missfiring pretty bad. The check engine light was on, the car also had no power. Took the car to the mechanic and he said his machine could not get a signal from the cpu. Got a used CPU from here, found out how to read the blinking light code which said lead ignition coil failure. Took the intake manifold off replaced the coil. Started the car up it reved up normal once then made a pop sound from the engine. The coil had black stuff oozing out of it. Took off the manifold again, repaired some frayed wires going to the coil. It did the same thing. The fuel pump also failed around this time, which I replaced. The mechanic that has the car says he thinks it's the ignitor. I wanted to know what you guys think. I am also going to put a wtb ad for an ignitor(I've never even heard of that part). Thanks

alexdimen

iTrader: (13)

The ignitor does indeed exist. Ignitors act like very fast switches for the coils by controlling the ground while there is always +12 to the coil IIRC.

Anywho... pictures of black stuff? never heard of that or seen it. Sounds like you need a new ignition harness.

There are standard methods of testing the ignitor signal to coil, but I doubt that it's burning out your coil.

t2terror

iTrader: (2)

Make sure to check your wire going to the coil thoroughly... I replaced my leading coil after i found out the wires going to it were pinched together by the bolt that holds the oil filler neck on. I had repainted and cleaned the neck and in my haste and low light conditions I managed to cause a short to the leading coil. And it melted the coil causing it to ooze out it's black casing.

Slacker87

iTrader: (1)

I really need help with this thing. The car has been down for a year and no one local can seem to fix it. I have the freaking money but no one to take it to. I really don't want to buy an ignitor if you don't think that is it. I don't even know what to do, I'll have to get it towed back to my place which I don't think the mechanic will be to happy about.

alexdimen

iTrader: (13)

I would try and replace the ignition coil and the ignition harness (both from mazda) and check spark wires, boots, resistances, etc. Still no pics of the failure...?

Banzai-Racing

iTrader: (11)

The last time we had a car in the shop that was melting coils, it was as a result of the front driver's side tire rubbing through the fender liner, then through the chassis harness. This created shorts that caused several coils to melt down exactly the way you have described. The bad part was it took a few destroyed coils to track down the problem. Just an idea.

linnadawg

iTrader: (14)

Unless the ignitor is shorted internally then its not the problem. You can test the ignitor by using a digital multimeter and the wiring diagrams from the FSM. You dont want to spend 580$ on a new ignitor for no reason. Unplug your coil harness and check each connector. All of the Black red striped wires are your grounds. The blue/white yellow/blue and red wires should have battery voltage when the key is forward. Take out the key, unhook the battery, and unplug the ecu. Check to see if any of the battery voltage wires are shorted to ground. If they are unplug the ignitor to see if the short goes away. If it does its between the ignitor and ecu. Trace the loom back to the ecu and see if theres any visible damage on the outside. Wires most likely do not short themselves out when they are nicely wrapped and protected. If you want to check the ignitor crank the car with digital voltmeter connected to the power and grounds for each connector and verify the multimeter starts to fluctuate between 0-12v. It doesnt work as well as a lab scope but its a quick test to get an idea.

linnadawg

iTrader: (14)

Its page Z28 of the factory wiring diagram by the way

Banzai-Racing

iTrader: (11)

The voltage is exactly opposite to what you described. The black with red is 12v+ to all the coils and the colored wires are the grounds from the ignitor.

linnadawg

iTrader: (14)

Damn. I dont know how I read that wrong. Well that diagnostic is useless then. Make sure your grounds are opening and closing while cranking. Make sure your B+ on the coil harness isnt shorted.

RIX-7

iTrader: (2)

Also check the coil pack lead at the plug where it connects to the main harness.
If its twisted the cables can short out just where they enter the plug. Happened to my Dads Rx. Rix

Indian

iTrader: (1)

any resolution to this problem?

Slacker87

iTrader: (1)

No it's been passed around from mechanic to mechanic. I think this is the fourth person I've had look at the car. If they say they cant fix it I think I will take it to the place in Atlanta or put the damn thing on craigslist. I will print out everyone's suggestions and give them to the mechanic. It seems to me like they're afraid to even try to fix the damn thing.

no_more_rice

Replace the coil wiring harness, they are fairly inexpensive from Malloy. If that doesn't fix it, you may have to replace the entire harness. Sounds like a short to me.