bad missfire

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nismoboy

New Member
ive got a bad missfire at 5000rpm, ive got a new coil, checked plugs seem ok, new dizzy cap, new rotor arm, the only thing i found was alot of resistance on the ht leads especially on lead 1.???

Does this mean the leads are fooked?
 
H

hmmm

Member
...

Hope you don't mind me asking here, but which Coil did you use? Was it a Standard Nissan one or an uprated one like the MSD?

Now, back to the topic at hand :wink:.
 
N

nismoboy

New Member
Re: ...

hmmm said:
Hope you don't mind me asking here, but which Coil did you use? Was it a Standard Nissan one or an uprated one like the MSD?

Now, back to the topic at hand :wink:.
Click to expand...
Its the msd ss blaster coil.
 
N

nismoboy

New Member
Re: ...

Ive ordered some new magnacor leads and ngk iridiums heat range 9 so i`ll see if this gets rid of the missfire.

It does seem to be a common problem tho i`ve been told when upping the boost that miss fires can happen on a pulsar, I personly think its just the boost blowing the spark out?

ive now done the above and it seem alot better, but today when racing a 600cc bike i got a missfire in 2 2nd gear around 6-7000 rpm ? So i gues the problem still hasnt gone its just moved, i was getting a missfire in 4th and 5th high in the revs but that seems to have gone and now it missfired high in second gear. any ideas?

things ive done so far..

removed msd coil and replaced it with old nissan one
new magnacor leads
new ngk plugs


might try fitting a new ignition amplifier any one know how much these cost?

thanks nis.
 
N

nismoboy

New Member
Re: ...

nismoboy said:
Ive ordered some new magnacor leads and ngk iridiums heat range 9 so i`ll see if this gets rid of the missfire.

It does seem to be a common problem tho i`ve been told when upping the boost that miss fires can happen on a pulsar, I personly think its just the boost blowing the spark out?

ive now done the above and it seem alot better, but today when racing a 600cc bike i got a missfire in 2 2nd gear around 6-7000 rpm ? So i gues the problem still hasnt gone its just moved, i was getting a missfire in 4th and 5th high in the revs but that seems to have gone and now it missfired high in second gear. any ideas?

things ive done so far..

removed msd coil and replaced it with old nissan one
new magnacor leads
new ngk plugs


might try fitting a new ignition amplifier any one know how much these cost?

thanks nis.
Click to expand...
 
Dooie Pop Pop

Dooie Pop Pop

New Member
about £35 quid iirc mate i thought id already posted a pic of the box for you :?
im using:

heat range 9 plugs(or so i was told im gonna check to make sure i wasn' t ripped off there too) .65 gap
oe leads
oe ignition amp and coil

not running as much boost as you though mate, ashills told me he was running the cheapest plugs he coulg get away with and a tight gap. he ran over 1.6 bar at totb with no probs :wink:

this thing with the msd is bothering me bigtime, does size matter?? what i mean is would it take longer to recharge to msd coil in time to deliver a proper spark because its bigger than the oe one :?

try a set of standard leads mate, imho i found the magnacors made the car feel fluffy when i tried em :( iv a couple of spare sets if you dont wanna buy some :wink:
 
N

nismoboy

New Member
thanks mate, i`ll try a new ignition amplifier first and see what happens, surely it cant be the magnacors? but if it does keep doing it i`ll get back to u one about the oe leads u have thanks mate nis.
 
N

nismoboy

New Member
The problem seems to be heat related, when its cold it's fine but after driving for a while it starts to stutter. It's usually in the lower gears :!:
 
N

nismoboy

New Member
yep there brand new, fitting these made it better as it was missfiring in fourth and fifth but now it only missfires in second gear mainly. So i am getting somewhere. Its just weird it does it when the cars hot or been driven for awhile.
 
N

nismoboy

New Member
I took my ignition amplifier off the car today and i when i took it off the bracket plate undernearth was covered in gearbox oil, so ive cleaned it all up and removed the paint on the contact side of the bracket for a good conection and put it back together so fingers crossed. I also relocated the ignition amplifier over to the near side wheel arch away from the heat of the engine as my problem seems heat related. i`ll let u know if it fixes the missfires. cheers nis.
 
P

poppa

Guest
Just seen this topic and must admit i also got same problem.

Can't wait to hear someones 100% solution to it.
 
N

nismoboy

New Member
nismoboy said:
I took my ignition amplifier off the car today and i when i took it off the bracket plate undernearth was covered in gearbox oil, so ive cleaned it all up and removed the paint on the contact side of the bracket for a good conection and put it back together so fingers crossed. I also relocated the ignition amplifier over to the near side wheel arch away from the heat of the engine as my problem seems heat related. i`ll let u know if it fixes the missfires. cheers nis.
Click to expand...
And guess what! NO it dosent :evil: :evil: it still missfires, so back to the drawing board.
 
Dooie Pop Pop

Dooie Pop Pop

New Member
if its a really nasty missfire i had the same problem with my car after the fueling had been setup completely wrong. sounded nasty like antilag :shock:
 
N

nismoboy

New Member
Dooie Pop Pop said:
if its a really nasty missfire i had the same problem with my car after the fueling had been setup completely wrong. sounded nasty like antilag :shock:
Click to expand...
its not really nasty, it just stutters and pops
 
P

poppa

Guest
Just solved my problem today.

Replaced plugs,ht leads,dizzy and rotor arm. The misfire at 5k rpm is now gone.

Used standard leads from nissan and plugs from halfords.
 
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