Help, ignition problem again :(

gtirx2

Member
Ok you may of read that my blaster coil died a short while back so i have disconected all of the msd ignition parts and gone back to the standard setup until a new coil arrives.Problem is when i plug it all back to standard spec i have a real bad ignition miss coming on boost and under heavy load,the only time the miss go's away is when i am above 6000rpm then it feels fine:? I have changed all the ignition parts one by one [except the distributer] and still no change.
Now here comes the weird bit,if i wire the standard coil up the WRONG way [large black/red wire to the coil - and the smaller green/yellow wire to the +]the dam thing runs perfect and does not miss a beat even if i give it hell:? !?
So any sugestion would be helpfull as i have not got a clue,and what makes it worse is it is starting to make me wonder if what ever is causing this may also be the reason why my blaster coil died so quick:?
 

stevepudney

GTiROC CHAIRMAN
Staff member
gtirx2 said:
Ok you may of read that my blaster coil died a short while back so i have disconected all of the msd ignition parts and gone back to the standard setup until a new coil arrives.Problem is when i plug it all back to standard spec i have a real bad ignition miss coming on boost and under heavy load,the only time the miss go's away is when i am above 6000rpm then it feels fine:? I have changed all the ignition parts one by one [except the distributer] and still no change.
Now here comes the weird bit,if i wire the standard coil up the WRONG way [large black/red wire to the coil - and the smaller green/yellow wire to the +]the dam thing runs perfect and does not miss a beat even if i give it hell:? !?
So any sugestion would be helpfull as i have not got a clue,and what makes it worse is it is starting to make me wonder if what ever is causing this may also be the reason why my blaster coil died so quick:?
Rich, I have a spare blaster coil if you want to try that out
 
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pulsarboby

Guest
try another coil on there! thats a strange problem:?
you need to put a kv meter on there to see whats happening when its wired up correctly.
if your down my neck of the woods again rich, bring the car up and il check it over for you with kv meter, dont want nothing for it, but a packet of ciggies wouldnt go amiss;-)
 

gtirx2

Member
Thanks for the offers guys:) ,steve i am a little bit unsure if to put another blaster coil back on it atm because just before my one died it was just starting to miss like it is know but not as bad,and i don't want to kill another one.It was also strange how that died, as it was still working ok ish and then i took the coil lead off to compression test the thing while the plugs where out and after that it worked no more:? ?
Bob i have a kv meter thing somewhere but i not sure if that will tell me what i need to know as the car will fire up fine with the coil plugged in the right way and run ok as long as it is not under heavy load if i try to boot it hard it splutters real bad lets out a bit of fuel smoke and sometimes silly size flames on the gear changes!
The other thing that is a bit strange is that if i get above 6000rpm it all seems fine and pulls as it should do with no miss,but i suspose that that could be that the ignition system is not under as much load in the higher revs?
As for wiring it up the wrong way,i had made a new bit of wire with plugs to go from the plug i put on loom to the coil,as the plug on the loom is usely plugged in to the msd ignition box wires.So i thought it was that messing me about,so then i just ran two pieces of wire with electrical connections on the ends from the coil and plug and went up the road to see if that helped which it had,but then i saw that i had plugged it in the wrong way round:doh:
I have tryed changing all of the igntion bits bar the distributer so i will try that and see what happens,if not i may have a wiring fault:? Does anyone know where the standard ballest resistor thing is in the loom and/or if that would cause a problem like this?as tbh there is not really many reasons why it should be doing this,i will have to have a look and try and work out how a coil is wired and why it would get more voltage when wired the wrong way.
 

Fusion Ed

Active Member
Your more likely to get misfire at max torque. That's when there is most air/fuel in a cylinder at any given cycle. That's why it clears up at higher rpm, where the efficiency of the engine drops.
 

gtirx2

Member
I am getting fault code 2.1 know which i think is ignition circult so i will have to check the loom and hope thats my problem!?
 
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pulsarboby

Guest
erase the code and wire it round the right way again and see if the code comes back again! if it does then theres deffo something amiss there somewhere rich, but what! i dont really know without running through the whole ign circuit.
could possibly even be an ecu fault!
 

gtirx2

Member
Yeah i will double check that its right but i am pretty sure it is as i did reset it after i changed the distributer,but saying that i did have a fiddle with the ignition turn off when i went up the road before i got the code.
I was thinking maybe to run a live feed straight from the battery + to the coil + instead of the black/red wire in the loom, just to make sure its getting anuff voltage under heavy load when i am booting it?If there is no change then its got to be the green/yellow wire which i think is the wire which tells it when to spark and release it charge?I also think this wire is wired in though the module and distributer somehow,i will have to look.
Otherwise like bob said it could be my ecu,so i will swap with another i have just to be sure.
I may also try wireing in an old school oil filed coil and see what that does,as i still can't get my head round why it works fine when i wire it up the wrong way round!
 

Fusion Ed

Active Member
Its not wired through the distributor, it comes from the ecu via the ign amp then to the coil, although in the loom it is all close together.
 

gtirx2

Member
Micra Ed said:
Its not wired through the distributor, it comes from the ecu via the ign amp then to the coil, although in the loom it is all close together.
Ok thanks i will have to have a look,i am sort of hoping if i wire the live straight off the battery it may solve my problem as i think it should be more simple if its the black/red swiched 12volt supply wire messing me around:? .
 

gtirx2

Member
Ok i think i may of sorted it now, sort of:lol: It was the plugs again:oops: When i swapped the plugs to try a different set when it first started missing they where gapped at 0.7 heat range 8 platinums and it still missed so i did not think it was the plugs:doh: so i put the denso ik27's gapped at 0.8 back in and thought it was something else:oops: .I finally put a new set of plugs in, 8 platinums and gapped them at 0.65 and it seems alright:)
I have since tryed gapping my denso ik27 down to 0.65 and it still misses so i think one off the plugs is fooked,once again them plugs have only been in for about 2000 miles [same as the blaster coil] and are dead:cry: .I also think maybe the spark is sparking out the side of the porseline bit on one of the plugs as there is a weird clean mark on one,it also seems the ik27s miss gets worse the hotter the engine gets so maybe there is a small crack in it that opens up with the heat?
So basicly my denso plugs[or at least one] may have died and my old problem http://www.gtiroc.com/forums/showthread.php?t=46120&highlight=ignition+miss of spark blow out on the standard setup is still there:?
Why i get spark blow out on a bar is beyond me?i am still pretty sure its down to one cylinder so i will have to solve this soon:evil: ,as surely i should be able to run atleast 0.7 gaps on a bar on the standard setup?
I have wonded if my compression ratio has anything to do with it as i think i worked it out at being 9.1:1 which maybe a little bit high?
I just hope that when the blaster coil died it was just a totaly seperate insident which caused the same sort of miss and when i put a new one on it it won't die again!
Also i have not tryed wireing the coil back to front again as basicly i just don't want to know, as its still messing with my head as to why the dam miss would go when wired like that,exspecialy when i think/know/sort of hope, that one of my denso plugs have died:shock: :oops: :lol::doh:
 

youngsyp

New Member
Bin the Denso's bud and go for the equivalent NGK Iridium plugs.

There have been several reports of issues with the Denso range, including from myself so, they don't seem to be up to the job ?!

I run 0.7mm on my set up and they behave perfectly. If you're getting the spark blown out though, it could be the plugs not getting the full current they need. Have you tested the leads for resistance and the coil for output ?

Paul
 

gtirx2

Member
Yeah i won't be buying denso again and proberly will try ngk's next,but for now i am just going to leave the cheap champion platinum 8's in and see how they do.
As for the resistance of the leads and coil i am not to sure how to test them tbh?
One good thing may of come of this tho as when i was looking about i found this post by campbellju...

Aftermarket capacitive discharge systems: Better for high boost high rev applications than OE. Will not give more power on their own but will allow more accurate tuning of the ignition map so in "theory" more power (At high boost/rpm)

However, their short duration is why they have to fire many times at low rpm with lean mixtures. Without this "feature", CD systems will misfire. Inductive OE systems with longer durations don't have this problem. However, running small plug gaps on an OE system would give similar problems.

and i was wondering if this is the reason for my set rev miss/burble i still get at set revs from my other ignition miss thread.So i may try and richen the fueling on my afc2 so at say 2500 set revs it richer to see if that helps.As campbellju post would sort of explain why the set revs burble is worse with the msd connected and not so bad on the standard setup,worth a try i think.
 

gtirx2

Member
I have just tryed upping the fueling and its seems to have done the trick with my set revs miss:-D I had to raise it a fair bit [like 40% on the afc2] but the burble defintaly got better/if not went altogether[with the msd connected] so i am pretty sure it is was what campellju was on about with the duration of the spark on these cdi units with lean mixtures at low revs.I am just guessing that when i hold the revs at set revs in netural it is obviosly not running that rich and is proberly running more on the lean side with no load on the engine so the cdi ignition unit is not igniting it as well as the standard inductive system with a longer spark duration would?
This would also explain why the only way i could get rid of the set revs miss/burble was to gap the plugs wide on the standard inductive system.
My only worrie now is that my R is running a bit lean under no load/light load situations which is causing the miss as no one else seems to get this burble like i do?
Anyway i am pretty happy as this has been a mystrey for me for a long time and tbh now i think i know what the problem is i don't think its much to worrie about under light load conditions.
My next wonder is if i was to get it remapped in the future would you benifit from mapping the car rich under light load conditions so that the short duration muti sparks of the msd system have a better chance of igniting the fuel/air mix better?
 
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