test procedure:

1. unplug coil pack.

2. while having someone crank the car, check maximum voltage to coil pack by probing power wire on coil pack harness (middle wire) and using either of the other two wires (brown or black w/ blue stripe) on the harness connector as a ground.

3. post results.

thanks in advance

I don't have a running 2GNT to test this with, but I wanted to give you a courtesy bump so someone will check this for you.

Originally posted by DarkOne
I don't have a running 2GNT to test this with, but I wanted to give you a courtesy bump so someone will check this for you.

mega appreciated :D

I will see if I cant get it up for you tonight. (wednesday)

Pardon my not having an answer for you but this is going to vary alot between voltmeters and how quickly they respond to the change in voltage. Also very dependent on how good the battery, the starter, and the compression of the engine its being tested on.

Just thought you should consider that...

Originally posted by red_vengance23
Pardon my not having an answer for you but this is going to vary alot between voltmeters and how quickly they respond to the change in voltage. Also very dependent on how good the battery, the starter, and the compression of the engine its being tested on. Just thought you should consider that...

what does compression and the starter have do to with this? not trying to sound rude.

Originally posted by halfasss101
I will see if I cant get it up for you tonight. (wednesday)

much appreciated

Speed the engine is rolling over is going to determine the rate the ground is being pulsed, which is going to affect what your meter reads. For instance, I have two meters one is a fluke that has features I will never use, the other a $3.99 "centech" or something like that, when measuring voltage that is pulsed such as the ignition or the fuel injectors, its going to show up as a duty cycle wich the fluke will read but display as 12.xx volts @ some percentage duty cycle. The centech will just show a number between 0 and 12. This is why I say it matters allot what meter people are using and the other variables. I'll have the Eclipse back in the shop on noon break today i'll check it out for ya.

Originally posted by red_vengance23
Speed the engine is rolling over is going to determine the rate the ground is being pulsed, which is going to affect what your meter reads. For instance, I have two meters one is a fluke that has features I will never use, the other a $3.99 "centech" or something like that, when measuring voltage that is pulsed such as the ignition or the fuel injectors, its going to show up as a duty cycle wich the fluke will read but display as 12.xx volts @ some percentage duty cycle. The centech will just show a number between 0 and 12. This is why I say it matters allot what meter people are using and the other variables. I'll have the Eclipse back in the shop on noon break today i'll check it out for ya.

well my problem is when i do this test, the max voltage i get through the grounds supplied by the ecu in the two wires is around 5v... but if i ground the power input to a ground like the battery terminal i get all 12v. I wanted to see what everyone else is getting because i believe this is why i'm not getting spark.

That is what I meant that ground is being pulsed while you are cranking which the multimeter is going to display as a voltage less than the battery volts because of only getting the ground side very briefely. Are your readings the same for both sides circuits A and B ? I ask because back in 2005 my ECU died by way of the coil driver circuit becoming a direct short to ground. One side of the plug pulsed a ground the other side was a dead short to ground, once plugged in to the coil it would drag the voltage down across the whole circuit which meant that I got no spark. Unless I pulled the pin for the shorted side out of the connector, which got me spark on cylinder 2 and 3. Took me awhile to figure that one out and even had techs with 20+ years experience scratching there heads.

Originally posted by red_vengance23
That is what I meant that ground is being pulsed while you are cranking which the multimeter is going to display as a voltage less than the battery volts because of only getting the ground side very briefely. Are your readings the same for both sides circuits A and B ? I ask because back in 2005 my ECU died by way of the coil driver circuit becoming a direct short to ground. One side of the plug pulsed a ground the other side was a dead short to ground, once plugged in to the coil it would drag the voltage down across the whole circuit which meant that I got no spark. Unless I pulled the pin for the shorted side out of the connector, which got me spark on cylinder 2 and 3. Took me awhile to figure that one out and even had techs with 20+ years experience scratching there heads.

how do i test for that? and how do i fix it if that is my problem?

also- I tested my battery at advanced and it only showed 25 cca out of 600... getting a new battery tomorrow.

if that info helps.

Just test from that center pin to the outer ones each separately or from battery positive to each outer pin if one of them is 12 volts all the time either your harness is pinched or rubbing somewhere or the ecu is toast for me it was the ecu but that is probably rare if your battery is shot obviously you need to start there =P

Originally posted by red_vengance23
Just test from that center pin to the outer ones each separately or from battery positive to each outer pin if one of them is 12 volts all the time either your harness is pinched or rubbing somewhere or the ecu is toast for me it was the ecu but that is probably rare if your battery is shot obviously you need to start there =P

well neither of them are showing 12v even when the car is cranking. if i use the battery positive and ground with one of the outer ones, i dont get any voltage until i try cranking the car, and they it only shows around 5v.

That sounds like what i would expect. You should not have any connection to ground at the outer pins unless the engine is cranking and even then its too quick for most meters to read the entire voltage unless its something higher end that can measure duty cycle. what you should be using to test that is a noid light, and no that is not the same as a test light. If the light flashes when you crank then its working like it should if you still do not have spark then your coil or wires are toast.

Originally posted by red_vengance23
That sounds like what i would expect. You should not have any connection to ground at the outer pins unless the engine is cranking and even then its too quick for most meters to read the entire voltage unless its something higher end that can measure duty cycle. what you should be using to test that is a noid light, and no that is not the same as a test light. If the light flashes when you crank then its working like it should if you still do not have spark then your coil or wires are toast.

ohk, new stuff:

When the coil is not plugged in, both grounds work and pulse just fine. when the coil is plugged in, it doesnt show a voltage reading.

is it supposed to?

Have you ohmed the coil ? check the resistance across each outside pin to the center pin I believe it should read somewhere around 16 ohms?

If its plugged in you will not be able to read pulsed ground on those pins anymore because that voltage will be "used" by the coil. however you should still be able to read battery volts from the center wire to the battery negative or any ground.

that all checked out. i went to auto zone and got another coil.. no spark. :(

How can i be getting the trigger signal and proper voltage.. but no spark..

That is an excellent question. The pins in that connector are not stretched at all are they ? As in they are all tight and making connection when they are plugged in ? How are you checking for spark, do you have the plugs all out of the cylinders and laying somewhere conductive to make ground ? Don't mean to sound obvious or offensive, but just making sure we are on the same page here.

Originally posted by red_vengance23
That is an excellent question. The pins in that connector are not stretched at all are they ? As in they are all tight and making connection when they are plugged in ? How are you checking for spark, do you have the plugs all out of the cylinders and laying somewhere conductive to make ground ? Don't mean to sound obvious or offensive, but just making sure we are on the same page here.

it is a new connector. i wired it in about 2 weeks ago because the other one was nasty. almost zero resistance from connector to ecu.


I am checking spark by having one plug wire plugged into the coil (coil is not bolted down.. just sitting on the valve cover), one spark plug into that plug wire, and grounding it on the exhaust manifold which i know is a good ground.

ALSO!!!!! when the coil is plugged in and the ignition is on, both ground wires have a constant ground (i can plug the coil in, turn the ignition to ON, and be able to read battery voltage by grounding on either of the two wires).

Well now there is a problem, you'll need the adjacent coil connection with a wire on it and a spark plug in it also to complete the circuit (1 has to be hooked up at the same time as 4 , or 2 has to be hooked up with 3). Try that and let us know, having ground when its plugged in and not having it when its not plugged in does not make any sense, the coil is not grounded anywhere by itself.

Also lay them next to eachother, the coil does not want a path to ground it wants a path to the other "tower" across from it. The wires are not always long enough to lay the plugs end to end, but if the threaded parts are touching that should be good.

so have 2 and 3 spark plugs touching threads with each other and thats it? or do i need to have them both grounded to the exhaust manifold as well?


and as far as the wires always being grounded goes...


what could cause this? because if they coil isnt plugged in, the battery wont ground to either wire.. but as soon as i plug in the coil, both wires work as a ground.

yes touch 2 and 3 threads together or 1 and 4 together when you check it. As for the ground are you trying to go from the battery positive or battery negative to these wires ? if you are trying to go from pos you should not get any reading if you go from negative you will see voltage from the center pin now flowing through the coil to the outter pins.

here is exactly what is going on(all with ignition on):

when the coil is plugged in:

Both outer wires will ground the battery positive tower and show 12v.

when cranking the car, the middle wire can be grounded to the battery negative tower and show proper voltage, but when grounded to outer wires, no voltage shows.

When the coil is not plugged in:

the outer wires wont ground the battery positive until i crank the motor.

If i use the middle wire as the positive and either outer as the negative, i get roughly 4v-6v.

the middle wire will show 12v if i ground to battery negative while cranking the motor.

Originally posted by bnisson
here is exactly what is going on(all with ignition on): when the coil is plugged in: Both outer wires will ground the battery positive tower and show 12v. when cranking the car, the middle wire can be grounded to the battery negative tower and show proper voltage, but when grounded to outer wires, no voltage shows. When the coil is not plugged in: the outer wires wont ground the battery positive until i crank the motor. If i use the middle wire as the positive and either outer as the negative, i get roughly 4v-6v. the middle wire will show 12v if i ground to battery negative while cranking the motor.

Ok, coil plugged in.

both outer wires being ground. This is not normal and should not happen, there should be no connection to ground in that connector for any reason at all plugged in or unplugged unless the engine is rotating. You have the propper condition when the coil is unplugged but not while plugged in. That is very odd and i dont see how the coil could do that but you should try another coil.

Originally posted by red_vengance23

Originally posted by bnisson here is exactly what is going on(all with ignition on): when the coil is plugged in: Both outer wires will ground the battery positive tower and show 12v. when cranking the car, the middle wire can be grounded to the battery negative tower and show proper voltage, but when grounded to outer wires, no voltage shows. When the coil is not plugged in: the outer wires wont ground the battery positive until i crank the motor. If i use the middle wire as the positive and either outer as the negative, i get roughly 4v-6v. the middle wire will show 12v if i ground to battery negative while cranking the motor.

Ok, coil plugged in. both outer wires being ground. This is not normal and should not happen, there should be no connection to ground in that connector for any reason at all plugged in or unplugged unless the engine is rotating. You have the propper condition when the coil is unplugged but not while plugged in. That is very odd and i dont see how the coil could do that but you should try another coil.

ive tried it with 3 coils, one of which was new from auto zone :(

any new ideas?


btw- i found this link for my coil:

http://www.msdignition.com/instructions/Products/Coils/8239.pdf?terms=8239

It shows that the power into the coil should be the far right terminal while the grounds are in the middle and far left. Could this be why i have no spark... because the coil is wrong?????

the wiring in that picture is certainly not like any neon or 420a ive ever run across but ive never used any MSD components either. As far as i knew the MSD coil was supposed to be a direct replacement without any alterations but i could be wrong. I can tell you for certain that if that is the way the MSD coil is made then it will not work when plugged into the factory wiring, you would have to move the pins around. The Center should be fed +12v from the ASD relay and the Outter 2 should be grounded through the ECU when the engine is cranking.