Stinger with 7M ignition - 3rd coil going nuts

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5uprahboy

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Aug 22, 2005
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Hey all

I've got the diodes wired in proprely - the first 2 coils are fine but the 3rd is going nuts - and only on one side of that 3rd coil - i.e. number 2 cylinder is firing slower than the other cylinders, but number 5 cylinder is firing almost constantly - you can barely see it not fire.....

Any thoughts what would cause this?
 
S

suprra_girl

7M POWAH! ;)
Mar 30, 2005
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also to add:

Have swapped in 3 different coil sets & changed ignitor

Voltage on cranking on each of the coil signal wires is from 1.25-2.73 in increasing increments to back down again, all 3 are reading very similar.
When the car starts cranking to fire the timing light signal is normal, once it actually starts #5 starts going psycho again.
 
S

suprra_girl

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Mar 30, 2005
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bigaaron said:
The ecu can't make one secondary of one coil have a problem.
Bad coil or bad spark plug wire or bad plug, maybe. Or you have a bad diode.
Click to expand...

Hey Aaron,
I have tried new leads and plugs and coils and ignitor to no avail
How do I test the diodes? At the ignitor end if I put a multimeter in continuity mode and test IGDA, which is PINK at the ECU plug, I should also see continuity on IGT on the ignitor?
The resistance between ECU and ignitor (while going through the diodes) is about 780ohms - is that ok? I'm using 1N4004 diodes. I have only tested between IGDA and PINK - but really I'm not sure how to actually test if a diode is working.....

Thats a lot of wording......
 
bigaaron

bigaaron

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Apr 12, 2005
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Most good digital multimeters have a diode test feature. The diode needs to be taken out of the circuit for testing. You can't tell if a diode is good with an ohm test alone.
 
S

suprra_girl

7M POWAH! ;)
Mar 30, 2005
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bigaaron said:
Most good digital multimeters have a diode test feature. The diode needs to be taken out of the circuit for testing. You can't tell if a diode is good with an ohm test alone.
Click to expand...

I was using the multimeter on diode mode - but testing with the diode still in the loom. I will take the loom apart tomorrow and test all 5 diodes individually.

From my understanding coil 1 fires with IDGA, coil 2 fires with IGDB and coil 3 fires with both IGDA and IGDB - but I'm now confused as to IGT's purpose and how the diode setup actually works.....

Can you explain please

Thanks
 
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5uprahboy

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Aug 22, 2005
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Right I tested all the diodes - they are all perfect - reading 430-434 one way and open the other with their polarity or "silver stripe" facing the correct way, i.e. towards the ignitor.

I have tested to make sure IG1 IG2 and IG3 go to their corrosponding wire on the igniter - i.e. IG1 to IGDA, IG2 to IGDB and IG3 to IGT.

There are no shorts anywhere - so fucked if I can figure out whats wrong :1zhelp: :icon_mad:
 
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5uprahboy

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Aug 22, 2005
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I have removed the 2nd trigger and re-gapped the primary. I have not touched the 24 tooth jobbie. The gap looks pretty tight anyway.
I am still however having the problem of number 3 coil sparking a shirtload more than the other 2.

I have changed the "Ign fire edge, Trigger edge and Sync edge" all to "falling" - What should I put for "Sync Pull up Resister" - yes or no?

I havent gone for a drive just yet, but the fact that the 3rd coil is still sparking more than the other 2 concerns me....
 
5

5uprahboy

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Aug 22, 2005
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Hey all,

I gave up in the end and bought from a wrecker a mitsi igniter from a V6 that simply has 3 "ins" and 3 "outs" and runs a wasted spark type ignition.

Everything is working perfectly so far :)

Bloody 7M parts :)
 
S

suprra_girl

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Mar 30, 2005
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The part number is J723T, has 2 plugs, 6 pin & 3 pin.
Its defintely easier than messing around with diodes hehe, and it's a much smaller ignitor.

Edit: No clue to whether they're the 3000gt ignitor, over here they're on the 2.0, 2.5 and 3.0L Gaylants (Galant).

Just make sure it's from a wasted spark v6 engine and you should be all good :)
 
I

IJ.

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Mar 30, 2005
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You need to get a dwell curve for whatever coils you're using and program that into the Stinger (if it will let you use a table) this will stop you cooking Coils. (ask how I know this)

It also gives a nice FAT spark for starting and pulls some as the voltage in the car rises with RPM.
 
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5uprahboy

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Aug 22, 2005
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IJ.;883083 said:
You need to get a dwell curve for whatever coils you're using and program that into the Stinger (if it will let you use a table) this will stop you cooking Coils. (ask how I know this)

It also gives a nice FAT spark for starting and pulls some as the voltage in the car rises with RPM.
Click to expand...

I'm using the 7M coils still - with the mitsi igniter....
So the dwell should be for whatever the coils prefer? Which for the 7M coils should be? I think I have about 2.6ms.....
 
bigaaron

bigaaron

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5uprahboy;873972 said:
I have removed the 2nd trigger and re-gapped the primary. I have not touched the 24 tooth jobbie. The gap looks pretty tight anyway.
I am still however having the problem of number 3 coil sparking a shirtload more than the other 2.

I have changed the "Ign fire edge, Trigger edge and Sync edge" all to "falling" - What should I put for "Sync Pull up Resister" - yes or no?

I havent gone for a drive just yet, but the fact that the 3rd coil is still sparking more than the other 2 concerns me....
Click to expand...

It should be rising edge and pullup resistor off for a stock 7m cps. As for the coils, I always use the stock ignitor because it's bullet proof and the dwell is preset. I couldn't say exactly what the stock coils will want for dwell from the Mitsu ignitor, but maybe look up what the MSD GM coils require and it should be about the same.
 
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5uprahboy

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Aug 22, 2005
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bigaaron;883160 said:
It should be rising edge and pullup resistor off for a stock 7m cps. As for the coils, I always use the stock ignitor because it's bullet proof and the dwell is preset. I couldn't say exactly what the stock coils will want for dwell from the Mitsu ignitor, but maybe look up what the MSD GM coils require and it should be about the same.
Click to expand...

Well thats the annoying thing, I'm not using 7M CPS - I'm using the 1G distributor as a CPS - but I think its the same as the 7M one.

If the CPS settings are wrong, i.e. falling edge and no pull up resister, would the car still run?

I thought the dwell is to be matched to the coils, not the igniter? Especially in the case of the 7M one as it has inbuilt dwell control.....
 
5

5uprahboy

New Member
Aug 22, 2005
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Auckland
bigaaron;883160 said:
It should be rising edge and pullup resistor off for a stock 7m cps. As for the coils, I always use the stock ignitor because it's bullet proof and the dwell is preset. I couldn't say exactly what the stock coils will want for dwell from the Mitsu ignitor, but maybe look up what the MSD GM coils require and it should be about the same.
Click to expand...

What should be rising edge? "trigger sensor" or "sync edge"?
And you say pullup resistor should be set to off is that for trigger edge or sync edge?
 
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