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Moved coil now have some problems

Posted: Sun Apr 05, 2009 8:26 pm
by NCpaj
Gday

well ive allways had problems with my car and water-- its an 86 2.6L petrol pajero (sigma engine). I run a breather from the dizzy, i have good leads that are silliconed up and the dizzy is silliconed up with the right sillicone. I also have a snorkel and have checked the air box, and air box to carby connnection and ive silliconed up any areas that could let water in

But i still have problems (insert pajero joke here :D ) So today i moved the coil to inside the cab, and wired it up etc, it starts fine and runs ok, however on the drive home (20mins) when i would stop for 1min or so at lights etc and then take off agian it would seem the stumble and miss, then a mini back fire then be sweet, no other problems other than that.


-The extended coil lead is a spark lead off a V8 that ive swapped the boots on, its 10mm compared to the coils normal 8mm. The made up one is 42 inches long.

-Im pretty sure that all the other wires i extended and crimped i used the same if not bigger wire on (for coil and ballast resistor.)

-Also how hot should a coil get? roughly?

-The leads are about 6mths old and ive got new spark plugs at home that ill put in tommorow- but the car never used to do that

-Also the Dizzy is electronic not points

-Ive also lost the tacho--short out? blow fuse?



Any ideas on this one???

Cheers

Posted: Sun Apr 05, 2009 8:29 pm
by berad
Most coils ive had anything to do with use the mounting bolts/bracket as an earth, is it mounted to something decent. the firewall etc,if it isnt it may cause excess heat, and in turn not work as it should.

Possibly not sufficient spark at idle and isnt burning all the fuel and semi fouling the plugs until you burn it off with normal driving once again.

Posted: Sun Apr 05, 2009 8:34 pm
by NCpaj
berad wrote:Most coils ive had anything to do with use the mounting bolts/bracket as an earth, is it mounted to something decent. the firewall etc, which would cause excess heat, and in turn not work as it should.

Possibly not sufficient spark at idle and is making a fuel buildup and semi fouling the plugs until you burn it off with normal driving once again.
ok Cheers thats sounds right,

yeah its mounted to the fire wall using 2 self tappers, however the fire wall has the factory stick on almost rubber like sound deadining sh*t on it.

Also forgot to add that i bought a new coil today Its a GX 80

Posted: Sun Apr 05, 2009 8:49 pm
by -Scott-
Mate - it's the longer wires. The signal is taking longer to get to the coil, and the spark is taking longer to get back, so the timing is retarded.

Advance your timing and you'll be sweet.

:P

Posted: Sun Apr 05, 2009 8:55 pm
by Shadow
-Scott- wrote:Mate - it's the longer wires. The signal is taking longer to get to the coil, and the spark is taking longer to get back, so the timing is retarded.

Advance your timing and you'll be sweet.

:P
are you serious?

You know electrons move just under speed of light right?

Posted: Sun Apr 05, 2009 8:59 pm
by DamTriton
Have you had the carby looked at?

Those symptoms sound far more likely to be a carby problem (blocked accelerator jet or broken mechanism), as the coil/ignition system seems to be working well at high rpm when it is actually at it most loaded (no described high rpm hesitation/stumbling).

Most carby's have an accelerator pump tha adds extra fuel when the pedal is rapidly pressed to the floor (taking off from traffic lights) and I would be my house (OK then, someone elses house) on it being the culprit. This leads to temporary fuel starvation from "leaning out" until the revs and load stabilizes.

The days of tuning/faultfinding carby's are lost on the young :roll: :D

Posted: Sun Apr 05, 2009 9:07 pm
by -Scott-
Shadow wrote:
-Scott- wrote:Mate - it's the longer wires. The signal is taking longer to get to the coil, and the spark is taking longer to get back, so the timing is retarded.

Advance your timing and you'll be sweet.

:P
are you serious?
No.
Shadow wrote:You know electrons move just under speed of light right?
Sort of... EMF (the voltage signal) travels along copper at close to the speed of light, but "electron speed" is harder to define. IIRC, "electron drift" speed is more in the order of metres per second, not millions of metres per second.

Posted: Sun Apr 05, 2009 9:20 pm
by NCpaj
DAMKIA wrote:Have you had the carby looked at?

Those symptoms sound far more likely to be a carby problem (blocked accelerator jet or broken mechanism), as the coil/ignition system seems to be working well at high rpm when it is actually at it most loaded (no described high rpm hesitation/stumbling).

Most carby's have an accelerator pump tha adds extra fuel when the pedal is rapidly pressed to the floor (taking off from traffic lights) and I would be my house (OK then, someone elses house) on it being the culprit. This leads to temporary fuel starvation from "leaning out" until the revs and load stabilizes.

The days of tuning/faultfinding carby's are lost on the young :roll: :D

umm no didnt think of that, the carby was rebuilt about 3 years ago (ages i know). But until i moved the coil i never had this problem.

:rofl: on the slow electrons

Posted: Sun Apr 05, 2009 9:24 pm
by Chucky
-Scott- wrote:
Shadow wrote:
-Scott- wrote:Mate - it's the longer wires. The signal is taking longer to get to the coil, and the spark is taking longer to get back, so the timing is retarded.

Advance your timing and you'll be sweet.

:P
are you serious?
No.
Shadow wrote:You know electrons move just under speed of light right?


Sort of... EMF (the voltage signal) travels along copper at close to the speed of light, but "electron speed" is harder to define. IIRC, "electron drift" speed is more in the order of metres per second, not millions of metres per second.

Unless it's AC then it gets slower and slower, all that running backwards and forwards wears them out eventually and you need to replace them with new electrons. A good sign when to replace the electrons is when the black smoke is let out of wires.

Just for information sake, the speed of light is changing. It's getting slower and slower all the time. It's believed that "Light speed" has finally realized that no matter how fast it gets there, Darkness always gets there first.

Who said that the speed of light was slow?

For more information look up Prof. Terry Pratchett.

Posted: Sun Apr 05, 2009 9:40 pm
by DamTriton
Chucky wrote:
-Scott- wrote:
Shadow wrote:
-Scott- wrote:Mate - it's the longer wires. The signal is taking longer to get to the coil, and the spark is taking longer to get back, so the timing is retarded.

Advance your timing and you'll be sweet.

:P
are you serious?
No.
Shadow wrote:You know electrons move just under speed of light right?


Sort of... EMF (the voltage signal) travels along copper at close to the speed of light, but "electron speed" is harder to define. IIRC, "electron drift" speed is more in the order of metres per second, not millions of metres per second.

Unless it's AC then it gets slower and slower, all that running backwards and forwards wears them out eventually and you need to replace them with new electrons. A good sign when to replace the electrons is when the black smoke is let out of wires.

Just for information sake, the speed of light is changing. It's getting slower and slower all the time. It's believed that "Light speed" has finally realized that no matter how fast it gets there, Darkness always gets there first.

Who said that the speed of light was slow?

For more information look up Prof. Terry Pratchett.
It is known that RF down a coax cable runs at approx .66-.75 the speed of light (old school: one foot per nanosecond). (True)

I would imagine heavy electron flows down a thick cable would run at about the speed of the Monash freeway at 07;00 am, and with as may bingles too. (err, maybe not so true :D )

Posted: Sun Apr 05, 2009 9:43 pm
by NCpaj
DAMKIA wrote:
Chucky wrote:
-Scott- wrote:
Shadow wrote:
-Scott- wrote:Mate - it's the longer wires. The signal is taking longer to get to the coil, and the spark is taking longer to get back, so the timing is retarded.

Advance your timing and you'll be sweet.

:P
are you serious?
No.
Shadow wrote:You know electrons move just under speed of light right?


Sort of... EMF (the voltage signal) travels along copper at close to the speed of light, but "electron speed" is harder to define. IIRC, "electron drift" speed is more in the order of metres per second, not millions of metres per second.

Unless it's AC then it gets slower and slower, all that running backwards and forwards wears them out eventually and you need to replace them with new electrons. A good sign when to replace the electrons is when the black smoke is let out of wires.

Just for information sake, the speed of light is changing. It's getting slower and slower all the time. It's believed that "Light speed" has finally realized that no matter how fast it gets there, Darkness always gets there first.

Who said that the speed of light was slow?

For more information look up Prof. Terry Pratchett.
It is known that RF down a coax cable runs at approx .66-.75 the speed of light (old school: one foot per nanosecond). (True)

I would imagine heavy electron flows down a thick cable would run at about the speed of the Monash freeway at 07;00 am, and with as may bingles too. (err, maybe not so true :D )

So a speed camera would have a field day in a Coax cable? :D

so will a coax cable fix my problems??? :cry:

Posted: Sun Apr 05, 2009 10:07 pm
by jet-6
No for a far superior install you would be best with quad parallel 10 core flat ribbon cable :P

Posted: Sun Apr 05, 2009 10:15 pm
by DamTriton
Or....you could put the coil back where it should be and elimiate any possibility that a misfire from the coil HT wire to ground as it goes through your firewall could be the cause of, or contribute to the current problem.

Lesson 1 in faultfinding: go back to the last known good operating configuration and work from there.

Posted: Sun Apr 05, 2009 10:22 pm
by NCpaj
DAMKIA wrote:Or....you could put the coil back where it should be and elimiate any possibility that a misfire from the coil HT wire to ground as it goes through your firewall could be the cause of, or contribute to the current problem.

Lesson 1 in faultfinding: go back to the last known good operating configuration and work from there.
ok, could a ht lead do that?? its going through a big grommet hole and being held roughly center of the hole by the rubber grommet.

Well i tested the longer lead before i lengthend the other wires and it seemd. Ahhh i always seem to solve one problem by creating another

Posted: Sun Apr 05, 2009 10:59 pm
by DamTriton
NCpaj wrote:
DAMKIA wrote:Or....you could put the coil back where it should be and elimiate any possibility that a misfire from the coil HT wire to ground as it goes through your firewall could be the cause of, or contribute to the current problem.

Lesson 1 in faultfinding: go back to the last known good operating configuration and work from there.
ok, could a ht lead do that?? its going through a big grommet hole and being held roughly center of the hole by the rubber grommet.

Well i tested the longer lead before i lengthend the other wires and it seemd. Ahhh i always seem to solve one problem by creating another
It would require a piece of equipment you would not have to test if it was arcing through the grommet to the firewall (a "Megger", generates high voltages sufficient to jump a spark).

I would strongly suggest taking a few steps back before jumping to any conclusions or you will never get the problem sorted.

1. put coil back where it should be
2. look at the carby and make SURE that it is OK (esp accelerator pump).
3. check fuel pump pressure (undersupply of fuel -> fuel starvation on acceleration)
4. any emmissions gear that could be a bit too old?? EGR valve,carbon cannister, etc?

The fact that you say you are getting nowhere with this problem probably means you're looking at the wrong things.

Posted: Sun Apr 05, 2009 11:13 pm
by -Scott-
I'm with Gary. Put the coil back and see if that fixes the problem. If it does, you've narrowed down the possibilities.

If it doesn't, you've eliminated one variable. And have an unknown number still to contend with. :P

Posted: Mon Apr 06, 2009 7:55 am
by mkpatrol
NCpaj wrote:
DAMKIA wrote:Or....you could put the coil back where it should be and elimiate any possibility that a misfire from the coil HT wire to ground as it goes through your firewall could be the cause of, or contribute to the current problem.

Lesson 1 in faultfinding: go back to the last known good operating configuration and work from there.
ok, could a ht lead do that?? its going through a big grommet hole and being held roughly center of the hole by the rubber grommet.

Well i tested the longer lead before i lengthend the other wires and it seemd. Ahhh i always seem to solve one problem by creating another

The average resistence reading for a HT lead is 3000 ohms /30cm.

You poor old coil is only used to having one that was 30-40cm long, now it has to deal with a coil lead that is over a metre long on the same output.

I recon I would run hot & cough & splutter if it was me.

Put the coil back where it was & find another way to seal your system.

Tried a rubber glove over the distributor cap for instance?

Works on the coil as well as long as you only cover the top with the wiring.

Sigma engines were renowned for not starting with a heavy dew so I think you are always going to have moisture problems. Its tha nature of the beast.

Back to basics, what actually stops the engine when it gets wet?

Unusual for the coil to give problems, its usually the dissy cap the gets wet that stops them.

Posted: Mon Apr 06, 2009 12:26 pm
by Jacked
coil wire too long. not a strong enough spark. get a spark tester on the end of you long lead and look at spark color and distance it will travel. then compare to the original one. you will see the difference yourself.

with short wire it will look like a strong blue spark. im betting with the long one it will be a dull orange and wont jump as far.

you could try closing up the gap on your plugs a little but you will start creating other problems.

Posted: Mon Apr 06, 2009 2:12 pm
by Chucky
Fit a diesel.

Never have to worry about ignition systems again ;)

Posted: Mon Apr 06, 2009 2:14 pm
by chimpboy
Chucky wrote:Fit a diesel.

Never have to worry about ignition systems again ;)
Or speeding tickets!

Posted: Wed Apr 08, 2009 11:52 pm
by DamTriton
Jacked wrote:coil wire too long. not a strong enough spark. get a spark tester on the end of you long lead and look at spark color and distance it will travel. then compare to the original one. you will see the difference yourself.

with short wire it will look like a strong blue spark. im betting with the long one it will be a dull orange and wont jump as far.

you could try closing up the gap on your plugs a little but you will start creating other problems.
Further explanation...

The resistance in the wires is not to reduce RF interference (although this is a secondary effect) it is actually to extend the spark duration. Rather than a big fat very short "ZAP" which may result in only a part of the charge being ignited, the resistance in the leads makes the spark have an extended "SIZZLE" therby igniting more charge in the cylinder. The resistance of the leads themselves is almost irrelevant compared to the spark gap resistance. The resistance across a spark plug with a spark across it (ionised) is essentially zero, ie a dead short. The resistance of the leads results in the longer time it takes an inductor (your coil) to "dump its load" of charge across a spark gap <Insert electronicky nerd talk here regarding T(greek tau)=L/R or see here for a more detailed explanation but in reverse on the disconnect... using a "dead short" ionised spark plug in the maths>

Remembering that cyl heads are designed these days with a swirl factored into them for this very purpose of evenly distributng the charge, the consequence is that the charge takes time to pass the spark, hence the need for a long duration spark. (it should be obvious why ricers all seem to have ignition issues now...)

HAVING SAID ALL THAT, you can have too much of a good thing, and in your case the length of the lead may be attenuating any spark that you do get through partial or complete crossfire to earth.

But what do I know, I'm a nurse.......

Posted: Thu Apr 09, 2009 10:13 am
by Jacked
hahahhahahahhahaha. *reads for 4th time an still dont understand*

lead resistance and plug resistance play a big part. in the initial jumping stage of the plug it does require alot of juice to overcome the gap. once there is an arc established the resistance is near 0.

yes it CAN work with a longer/higher resistance lead problem being his coil doesnt have enough power to overcome it completely. producing a shorter duration "colder" spark.

from meomory anything over 14k ohms is just too much resistance to be overcome causing misfire etc

Posted: Thu Apr 09, 2009 7:49 pm
by DamTriton
Jacked wrote:hahahhahahahhahaha. *reads for 4th time an still dont understand*

lead resistance and plug resistance play a big part. in the initial jumping stage of the plug it does require alot of juice to overcome the gap. once there is an arc established the resistance is near 0.

yes it CAN work with a longer/higher resistance lead problem being his coil doesnt have enough power to overcome it completely. producing a shorter duration "colder" spark.

from meomory anything over 14k ohms is just too much resistance to be overcome causing misfire etc
Fair point :lol: :lol: :lol:

How about I try to explain it in terms you may understand, and elaborate on your final point for the clarity of others seeking wisdom....

Think of the coil as your bladder, fully charged and ready to burst.

Now in most young men this is not a problem you stand at the trough and let it rip as quickly as possible. Now you young folk would realise that if you stand too close you'll get a bit of backsplash on your shoes, not a good thing... What you do is try to restrict the flow rate a bit to stop it splashing, but not enough to "fall short of the mark". A secondary effect of this is that it takes an extra bit of time at the trough to do the job. This is the effect the resistor in the leads of your ignition system plays.

Now consider poor old Grandpa with his "old man's dribble" prostrate problem. He has problems even getting a stream to the trough, let alone maitaining it for any length of time, added to the problem of him never feeling like he has emptied after anyway. This is the problem of too much resistance in the ignition system not alowing enough volts to maintain the spark, and possibly not fully discharging the coil between sparks.

Now how is that for tech you can understand :D :D :D :lol: :lol: :lol: :armsup: :armsup: :armsup:

Re: Moved coil now have some problems

Posted: Fri Apr 10, 2009 11:23 am
by 80's_delirious
NCpaj wrote:Gday

well ive allways had problems with my car and water-- its an 86 2.6L petrol pajero (sigma engine). I run a breather from the dizzy, i have good leads that are silliconed up and the dizzy is silliconed up with the right sillicone. I also have a snorkel and have checked the air box, and air box to carby connnection and ive silliconed up any areas that could let water in

But i still have problems (insert pajero joke here :D ) So today i moved the coil to inside the cab, and wired it up etc, it starts fine and runs ok, however on the drive home (20mins) when i would stop for 1min or so at lights etc and then take off agian it would seem the stumble and miss, then a mini back fire then be sweet, no other problems other than that.


-The extended coil lead is a spark lead off a V8 that ive swapped the boots on, its 10mm compared to the coils normal 8mm. The made up one is 42 inches long.

-Im pretty sure that all the other wires i extended and crimped i used the same if not bigger wire on (for coil and ballast resistor.)

-Also how hot should a coil get? roughly?

-The leads are about 6mths old and ive got new spark plugs at home that ill put in tommorow- but the car never used to do that

-Also the Dizzy is electronic not points

-Ive also lost the tacho--short out? blow fuse?



Any ideas on this one???

Cheers
does the Pajero incorporate a resistor wire into the ignition harness?
cars Ive fiddled with in the past had a long length of resistor wire so voltage to the ignition system was correct. The resistor wire would often snake back and forth within the wiring harness so that the correct length was used.
If your Paj has this and you have extended it or changed the length it may have an effect?
(its been fifteen years since i fiddled with petrol engine so may be barking up the wrong tree) :oops:


Oh and dont forget to fit 3 Hiclones and a flux capacitor :lol:

Re: Moved coil now have some problems

Posted: Fri Apr 10, 2009 1:01 pm
by DamTriton
80's_delirious wrote:
NCpaj wrote:Gday

well ive allways had problems with my car and water-- its an 86 2.6L petrol pajero (sigma engine). I run a breather from the dizzy, i have good leads that are silliconed up and the dizzy is silliconed up with the right sillicone. I also have a snorkel and have checked the air box, and air box to carby connnection and ive silliconed up any areas that could let water in

But i still have problems (insert pajero joke here :D ) So today i moved the coil to inside the cab, and wired it up etc, it starts fine and runs ok, however on the drive home (20mins) when i would stop for 1min or so at lights etc and then take off agian it would seem the stumble and miss, then a mini back fire then be sweet, no other problems other than that.


-The extended coil lead is a spark lead off a V8 that ive swapped the boots on, its 10mm compared to the coils normal 8mm. The made up one is 42 inches long.

-Im pretty sure that all the other wires i extended and crimped i used the same if not bigger wire on (for coil and ballast resistor.)

-Also how hot should a coil get? roughly?

-The leads are about 6mths old and ive got new spark plugs at home that ill put in tommorow- but the car never used to do that

-Also the Dizzy is electronic not points

-Ive also lost the tacho--short out? blow fuse?



Any ideas on this one???

Cheers
does the Pajero incorporate a resistor wire into the ignition harness?
cars Ive fiddled with in the past had a long length of resistor wire so voltage to the ignition system was correct. The resistor wire would often snake back and forth within the wiring harness so that the correct length was used.
If your Paj has this and you have extended it or changed the length it may have an effect?
(its been fifteen years since i fiddled with petrol engine so may be barking up the wrong tree) :oops:


Oh and dont forget to fit 3 Hiclones and a flux capacitor :lol:
Most cars bolt a big resistor to the top of the coil that is cut out of the circuit while starting for maximum bang, but is in the circuit when the car is running. Never seen a vehicle that uses resistive wire within the loom :shock: :shock: :shock: . That is DEFINITELY asking for problems regarding heating of the insulation of it and surrounding wires. There are two DC feeds to the resistor, the full 12 V coming from the "Start" position on the ignition key circuit (along with actuating the starter motor), and a second feed from the "Run" position of the ignition key circuit.

|-------< power from "Run" postion of ign cct, ie, while car is normally running
|
)
( Resistor
)
|
|--------< Power from the "Start" position when cranking. When in "Run" mode the voltage here is usually about 7-8 volts
|
@
@ Coil
@
|
\ Points
|
|--------> to ground