http://forum.miata.net/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=5&t=036566

any advice is greatly appreciated.

what year model is the car?

did you open/tap into any existing wires?

did any fuse blow? (what location # and amp rating)

does the car have an alarm? is it stock or aftermarket?

did you wire in an amp?

you wont need to remove the spark plugs to test for spark, infact you should leave then in when you do.
when you crank the engine, does the tach bounce at all?
be very careful when testing for spark. really.

what year model is the car?
1995 base model

did you open/tap into any existing wires?
i used the existing stereo power lines and ground.

did any fuse blow? (what location # and amp rating)
yes, the 'engine' fuse under the dash blew. 10 amp

does the car have an alarm? is it stock or aftermarket?
no alarm

did you wire in an amp?
yes, with a direct line to the battery and its own ground.

you wont need to remove the spark plugs to test for spark, infact you should leave then in when you do.
yeah, i realized that after i posted. i am not getting a spark, nor is there any power entering the coils. none that i could see on a digital meter, anyway. maybe its too quick to spot a change in the digital one. ill try my analog meter tonight

when you crank the engine, does the tach bounce at all?
i am not sure. i can certainly find out tonight.

do you remember what you did that caused the fuse to pop?

in most cases, the fuel circuit wont run if there is no ignition trigger. this doesn't mean 'spark', but but the trigger that tells the coil(s) _when_ to spark.

take a little time to check all other electrical bits (inside lights, cig lighter, horn, power windows......)

if you find anything else unusual it can really help pin point the offending circuit.

http://www.madracki.com/miata/images/wiring/95sys.pdf

any specific components i should concentrate on using that as reference?

check for power at the blue lead at the back of the ignition switch(while you crank)., it feeds the coils.
do you need a schematic? (opps, never mind)

Is Ed (edsmiata) around??? Maybe he could give some recommendations.

You absolutely need to pull out a spark plug, and then get someone to crank the engine for a second or two while you observe whether the plug is firing or not. EDIT: it will not fire by just holding it in the air -- you'll have to touch it briefly against the block, far far away from any place anywhere near gasoline or vapours. Or hook up a timing light instead of pulling the plug.

If it *is* firing, then your engine is flooded (petrol), and this can be solved by pulling the rest of the plugs and letting the fuel evaporate for an hour or two. There are other ways to unflood an engine as well.

Cheers

we did this last night. no spark was generated. we rechecked and power is definitely getting to the coils. the ECU is sending a signal to the coils. the ground on the coils is good. i just cant figure out how an empeg install would break both coils. im searching for some in junk yards. hopefully i can throw new ones in there and it just works.

Paul,

Just saw this thread. My first recommendation would be to check the fuel pump for there may be a cut off. Second would be to take it to the dealer. As you know this car is very small and almost impossible to see if fuses are blown without taking them out one at a time.

i had this problem with my explorer where a voltage converter blew out one of the power ports. As it was still under warranty i too kit back to the dealer who found a fuse box i never knew existed.

there is certainly a price for convenience and mybe a trip to the Mazda dealer is worth that price....or maybe just giving a call to them for some advice

Ed

Coils? Plural? What sort of coil, oil can or transformer? Is this a distributorless ignition?

Can you see 12-16V square waves going into the low voltage side from the ECU? If so, have you checked for carbon tracking down the outside of each spark plug? Did you do Mark's spark plug test in the dark to check if the HT is shorting along the outside of the plug leads? Are the plug leads clean and free of oil?

Coils do fail, but for two to fail at once is odd. It would be helpful if you could decribe the ignition system a bit more.

Engine fuse? Do you mean that the engine has a ten amp fused ignition feed line?

You should stick your meter (whatever type) on the 50V AC setting and measure the input on the low voltage side, coming from the ECU. If there is a square wave coming in, this will be seen by the meter as AC and you will either get needle sweeps, or averaging of the value on the digital.

One thing to check is that you have not destroyed the interference suppressor Caps on the ignition, which usually go short circuit, killing the ignition. Having said that, I've also had one go open circuit too.....

interference suppressor caps is a new one to me. any idea what they might look like?

using an analog meter i did see voltage on the low voltage side coming from the ECU. when i measured i didnt have it set to AC. i showed about 7 pulsing volts DC, though.

OK, that does tend to imply that the ECU is sending a signal to the low voltage side of the coil(s). Does it seem to be roughly in time with the rate the engine is cranking?

I assume that the fuel pump is turning: can you hear it while you are cranking (not just while the ignition is on)?

Can you smell petrol while cranking? Sniff the exhaust when you stop cranking for a few seconds.

The supressor cap (depending on manufacture) could be either a shiny cylinder an inch long with a wire coming out, with the case screwed to the chassis and the wire connecting to the coil (I am still not sure if you are can or transformer type). Alternatively, it might be a black plastic oblong about the size of a small box of matches, again bolted to chassis and the lead going to either the frame or the low tension side of the coil. I would guess since you are ECU with injection and no points (I assume???) that you will not have a points supressor (shiney can either in the distributor or outside on the LT wire) but will have an interference supressor (black plastic block).

If the supressor cap goes short, then the signal from the ECU will simply run to earth and not reach the LT side of the coil. Hence, examine the coil, and find the power lead (if it's can) or the ECU input line (transformer) and make sure that only these leads are connected. You will probably need to check the ignition circuit cct diagram in the manual (hope you have one) as I can only generalise here. If you are sure that only the input lead to the coil is connected, and the frame is earthed, then try to start it again. Bear in mind that you have probably been doing a lot of cranking and there may be petrol in the system, in the heads, etc. so ventilate and dry out first. Do NOT be tempted to try starting the car with your foot on the accelerator.

Let me know what coil type you have.

i would be more than happy to let you know what type of coil mine is.

http://users.pandora.be/miata/english/techie/coil_swap.htm

the first 3 pictures on that page are the same as what i have in mine.

Hmmmm.... does your tacho still work?

Might be worth disconnecting the tacho wire from the coil pack. You have transformer type dual-drive coils (wasted spark - both coils fire at once). There will be no suppressors visible on this type - they will be built into the coil pack.

Not hugely sure at this point. Were these 1.8 coils originally on your car, or have you also done the conversion shown in this article?

ive decided to take my car in to a local dealer. having been without the car for over a week has frustrated me so much that im going to pay them to tell me whats wrong. thanks for all of the great advice, though. i appreciate it.