Mazda MX-6 Forum banner
1 - 9 of 9 Posts

·
Registered
Joined
·
790 Posts
Discussion Starter · #1 ·
so at the end of the summer i did the hei mod and added an external coil thinking it would give me a better spark, now it doesnt run right or at all. not sure if they are related but i am fouling the plugs something awful and it drowns whenever i try to start it. when it is warm it runs fine. my mechanic was saying something about how a stronger spark means it need less fuel or something like that.
can anyone explain for me why if i have a stronger spark i would need less fuel in the cylinder? or does having the external coil somehow give me a weaker spark?
i dont know what to do about my car and either does my mechanic so any help would be apreciated
 

·
Registered
Joined
·
1,822 Posts
there's no explantion to be given, ask ur mechanic to tell u where he learnt that.
 

·
Registered
Joined
·
891 Posts
dsr30 said:
there's no explantion to be given, ask ur mechanic to tell u where he learnt that.
maybe he didnt learn it. He just made it up and started believing in what comes out of his mouth
 

·
Registered
Joined
·
3,167 Posts
My guess: the HEI mod is incorrectly installed or is using incorrect parts and the result is a weaker spark, not stronger.

Your mechanic is just phoning it in...he's clueless.

Check the wiring and mod install. I suspect you'll find you problem thereabouts.
 

·
Registered
Joined
·
1,291 Posts
wut mike said^^^ running rich means ur not burning all of ur a/f, if u had a stronger spark it SHOULD burn more than a weaker spark....u might even be running the wrong plugs, but most likely a wiring problem..might even be just a coincidence and possibly related to oter maintenance since ur mechanic dont seem that knowledgable he wouldnt know wut to look for
 

·
Registered
Joined
·
790 Posts
Discussion Starter · #8 ·
he is a good mechanic, he has told me he doesnt know how to deal with it and is trying to find me someone who might, and hasnt even charged me for all the time he has spent on it. i will check out the wiring though all the conections are soldiered and i didnt have this problem for a while after i originaly did it...

could the coil be dieing even though it is only a few months old? and is there anything i can do other than an external coil to make the ignition stronger?
 

·
Registered
Joined
·
3,167 Posts
chaos14 said:
he is a good mechanic, he has told me he doesnt know how to deal with it and is trying to find me someone who might, and hasnt even charged me for all the time he has spent on it. i will check out the wiring though all the conections are soldiered and i didnt have this problem for a while after i originaly did it...

could the coil be dieing even though it is only a few months old? and is there anything i can do other than an external coil to make the ignition stronger?
Coils die in most cases because they overheat, causing internal insulation breakdowns that reduce the effective winding ratio between the primary and secondary windings. In the old days, a "ballast" resistor, in some cases a big multi-watt ceramic deal (in others a length of calibrated wire), was used to drop the voltage supplied to the coil by about 3V or so to keep the thing from heating too much. The location of the coil, exposure to heat or road spray/debris can also affect its life.

Soldered connections, believe it or not, are not the best for automotive wiring. Crimps are always preferred because such joints have far superior fatigue resistance. The type of vibration found under the hood of cars, from engine harmonics to suspension impacts, can mince a solder joint very quickly.

If you have access to a scope (your mechanic might have one), get it on there and examine the signals. Specifically, check the voltage at the primary side of the coil and the signalling. With the coil disconnected, check the internal resistances of the coil and, if possible, compare the readings to a new coil of the same type. You might not be able to check for internal insulation breakdowns (unless they're dead shorts) this way since they might not show up until the coil secondary reaches a few kilovolts or so but a basic resistance check can reveal obvious problems.
 
1 - 9 of 9 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top