Ok, I'm confused here, even though the coil has two seperate spark plug
wires there is only one wire coming from the points and distributor
rotor to send spark to each cylinder, so how does each cylinder fire on
its own at different times?
Here is why I am asking, my thinking with this was that the coil always
fires both cylinders at the same time since there isn't a distributor
rotor for this and both plug wires come out of the same coil housing,
so I tried to hook up my VW coil so it could fire both cylinders and
instead it wanted to back fire through the intake a little and it
wouldn't attempt to start as well as it did last night when I had the
coil hooked up to one cylinder. So I hooked up just the drivers
cylinder and it fired up and ran on one cylinder, sounding much like a
Autopia car at Disneyland.
So the good news is that I now can get it to run but only on one
cylinder at a time until my replacement coil arrives.
So can some explain this to me how it works?
Thanks,
Mike
Baffled by the ignition system
Re: Baffled by the ignition system
Hi Mike,
Here is some more info for you about why 1 coil did not work to fire both cylinders.
Someone else is calling the method used by the 600 as a wasted spark ignition....sounds
good to me. Both plugs are being sent high voltage at the same time and if you have a dual
output ignition coil everything works fine. And when you connect the coil to one cylinder it worked ok
on the one cylinder. When you connected the output of the coil to both cylinders, it did not work properly.
Why was that? Because one cylinder was at the top of its compression stroke while the other cylinder was at the end of its exhaust stroke. When the high voltage was applied to both cylinders from your coil, it chooses the path of least resistance which will be the side on the exhaust stroke. Your coil is developing a voltage which keeps increasing until it can cause a spark in the cylinders. The cylinder containing the spent exhaust gases probably only needs a couple thousand volts to spark while the cylinder containing the the air/fuel mixture under compression probably needs 10 to 15,000 volts to spark. So, the coil dumps its energy into the side with the exhaust gases and now you have a cylinder full of air/fuel mixture
which has not ignited. When this cylinder is beginning its exhaust cycle it is under very little compression because the exhaust valve is opening. Now when your coil is ready to dump its energy, it sees a cylinder under compression (full of air/fuel) and it sees another cylinder under very little compression (full of air/fuel because it did not ignite on the previous cycle). The cylinder which gets ignited is the one requiring the lowest voltage..... the cylinder on its exhaust cycle. And since the cylinder is full of air/fuel, it gets ignited.
Why is it backfiring through the intake? Normally the hot, spent exhaust gases would be exiting through the exhaust port at high velocity when the spark plug on this cylinder is fired. In your case, you have an air/fuel mixture which has not been ignited which is being pushed out the exhaust port at a lower velocity when the spark plug ignites it. This causes an explosion of the mixture which continues to burn as the exhaust valve closes and the intake valve opens. The still burning mixture combines with the fresh intake charge and you have combustion occuring on the intake stroke. You will hear the backfire through intake plus you may hear some popping in the exhaust side from that mixture being combusted.
BTW, when you look at the spark across your spark plug when it is outside of the engine, the voltage at the plug is much lower than when it gets placed back into the engine. Outside of the engine, the spark plug is not under compression and the coil only needs to develop a couple thousand volts to jump the gap across the plug. Inside the engine and with the cylinder under compression, the spark plug needs over 10,000 volts for the spark to jump the gap. If your spark plug wires are defective, the ignition coil may be dumping its energy between the plug wires and the engine chassis and not letting the energy get to the spark plug. If your defective wiring has a breakdown voltage of 3,000 volts, when you check the plug outside of the engine it looks like it is working because you can see the spark at the plug (only 2,000 volts needed) but when the plug is installed in the engine and would need 10,000+ volts to make it spark, the energy instead goes into creating 3,000 volts and letting the spark occur between the plug wire and the chassis.
Hope I didn't put you to sleep,
Dale
Here is some more info for you about why 1 coil did not work to fire both cylinders.
Someone else is calling the method used by the 600 as a wasted spark ignition....sounds
good to me. Both plugs are being sent high voltage at the same time and if you have a dual
output ignition coil everything works fine. And when you connect the coil to one cylinder it worked ok
on the one cylinder. When you connected the output of the coil to both cylinders, it did not work properly.
Why was that? Because one cylinder was at the top of its compression stroke while the other cylinder was at the end of its exhaust stroke. When the high voltage was applied to both cylinders from your coil, it chooses the path of least resistance which will be the side on the exhaust stroke. Your coil is developing a voltage which keeps increasing until it can cause a spark in the cylinders. The cylinder containing the spent exhaust gases probably only needs a couple thousand volts to spark while the cylinder containing the the air/fuel mixture under compression probably needs 10 to 15,000 volts to spark. So, the coil dumps its energy into the side with the exhaust gases and now you have a cylinder full of air/fuel mixture
which has not ignited. When this cylinder is beginning its exhaust cycle it is under very little compression because the exhaust valve is opening. Now when your coil is ready to dump its energy, it sees a cylinder under compression (full of air/fuel) and it sees another cylinder under very little compression (full of air/fuel because it did not ignite on the previous cycle). The cylinder which gets ignited is the one requiring the lowest voltage..... the cylinder on its exhaust cycle. And since the cylinder is full of air/fuel, it gets ignited.
Why is it backfiring through the intake? Normally the hot, spent exhaust gases would be exiting through the exhaust port at high velocity when the spark plug on this cylinder is fired. In your case, you have an air/fuel mixture which has not been ignited which is being pushed out the exhaust port at a lower velocity when the spark plug ignites it. This causes an explosion of the mixture which continues to burn as the exhaust valve closes and the intake valve opens. The still burning mixture combines with the fresh intake charge and you have combustion occuring on the intake stroke. You will hear the backfire through intake plus you may hear some popping in the exhaust side from that mixture being combusted.
BTW, when you look at the spark across your spark plug when it is outside of the engine, the voltage at the plug is much lower than when it gets placed back into the engine. Outside of the engine, the spark plug is not under compression and the coil only needs to develop a couple thousand volts to jump the gap across the plug. Inside the engine and with the cylinder under compression, the spark plug needs over 10,000 volts for the spark to jump the gap. If your spark plug wires are defective, the ignition coil may be dumping its energy between the plug wires and the engine chassis and not letting the energy get to the spark plug. If your defective wiring has a breakdown voltage of 3,000 volts, when you check the plug outside of the engine it looks like it is working because you can see the spark at the plug (only 2,000 volts needed) but when the plug is installed in the engine and would need 10,000+ volts to make it spark, the energy instead goes into creating 3,000 volts and letting the spark occur between the plug wire and the chassis.
Hope I didn't put you to sleep,
Dale
> Ok, I'm confused here, even though the coil has two seperate spark plug
> wires there is only one wire coming from the points and distributor
> rotor to send spark to each cylinder, so how does each cylinder fire on
> its own at different times?
> Here is why I am asking, my thinking with
> this was that the coil always
> fires both cylinders at the same time since
> there isn't a distributor
> rotor for this and both plug wires come out of
> the same coil housing,
> so I tried to hook up my VW coil so it could fire
> both cylinders and
> instead it wanted to back fire through the intake a
> little and it
> wouldn't attempt to start as well as it did last night when > I had the > coil hooked up to one cylinder. So I hooked up just the drivers
> cylinder and it fired up and ran on one cylinder, sounding much like a
> Autopia car at Disneyland.
> So the good news is that I now can get it to
> run but only on one
> cylinder at a time until my replacement coil
> arrives.
> So can some explain this to me how it
> works?
> Thanks,
> Mike
Re: Baffled by the ignition system
Thanks Dale,
That all makes a lot of sense, thanks for taking the time to
explain it the way you did as I didn't think about the current taking
the path with the least amount of resistance.
Mike
That all makes a lot of sense, thanks for taking the time to
explain it the way you did as I didn't think about the current taking
the path with the least amount of resistance.
Mike
--- In
anzhonda600owners@yahoogroups.com
, goinhm@... wrote:
> Hi Mike,
> Here is some more info for you about why 1 coil did not work to
fire both
> cylinders.
> Someone else is calling the method used by the 600 as a wasted
spark
> ignition....sounds
> good to me. Both plugs are being sent high voltage at the same
time and if
> you have a dual
> output ignition coil everything works fine. And when you connect
the coil
> to one cylinder it worked ok
> on the one cylinder. When you connected the output of the coil
to both
> cylinders, it did not work properly.
> Why was that? Because one cylinder was at the top of its
compression
> stroke while the other cylinder was at the end of its exhaust
stroke. When the
> high voltage was applied to both cylinders from your coil, it
chooses the path
> of least resistance which will be the side on the exhaust stroke.
Your coil
> is developing a voltage which keeps increasing until it can cause
a spark in
> the cylinders. The cylinder containing the spent exhaust gases
probably
> only needs a couple thousand volts to spark while the cylinder
containing the
> the air/fuel mixture under compression probably needs 10 to 15,000
volts to
> spark. So, the coil dumps its energy into the side with the
exhaust gases and
> now you have a cylinder full of air/fuel mixture
> which has not ignited. When this cylinder is beginning its
exhaust cycle it
> is under very little compression because the exhaust valve is
opening. Now
> when your coil is ready to dump its energy, it sees a cylinder
under
> compression (full of air/fuel) and it sees another cylinder under
very little
> compression (full of air/fuel because it did not ignite on the
previous cycle). The
> cylinder which gets ignited is the one requiring the lowest
voltage..... the
> cylinder on its exhaust cycle. And since the cylinder is full of
air/fuel,
> it gets ignited.
> Why is it backfiring through the intake? Normally the hot, spent
exhaust
> gases would be exiting through the exhaust port at high velocity
when the
> spark plug on this cylinder is fired. In your case, you have an
air/fuel
> mixture which has not been ignited which is being pushed out the
exhaust port at a
> lower velocity when the spark plug ignites it. This causes an
explosion of
> the mixture which continues to burn as the exhaust valve closes
and the intake
> valve opens. The still burning mixture combines with the fresh
intake
> charge and you have combustion occuring on the intake stroke. You
will hear the
> backfire through intake plus you may hear some popping in the
exhaust side
> from that mixture being combusted.
> BTW, when you look at the spark across your spark plug when it is
outside
> of the engine, the voltage at the plug is much lower than when it
gets placed
> back into the engine. Outside of the engine, the spark plug is
not under
> compression and the coil only needs to develop a couple thousand
volts to
> jump the gap across the plug. Inside the engine and with the
cylinder under
> compression, the spark plug needs over 10,000 volts for the spark
to jump the
> gap. If your spark plug wires are defective, the ignition coil
may be
> dumping its energy between the plug wires and the engine chassis
and not letting
> the energy get to the spark plug. If your defective wiring has a
breakdown
> voltage of 3,000 volts, when you check the plug outside of the
engine it looks
> like it is working because you can see the spark at the plug (only
2,000
> volts needed) but when the plug is installed in the engine and
would need 10,000+
> volts to make it spark, the energy instead goes into creating
3,000 volts
> and letting the spark occur between the plug wire and the chassis.
> Hope I didn't put you to sleep,
> Dale
> Ok, I'm confused here, even though the coil has two seperate spark
plug
> wires there is only one wire coming from the points and
distributor
> rotor to send spark to each cylinder, so how does each cylinder
fire on
> its own at different times?
> Here is why I am asking, my thinking with this was that the coil
always
> fires both cylinders at the same time since there isn't a
distributor
> rotor for this and both plug wires come out of the same coil
housing,
> so I tried to hook up my VW coil so it could fire both cylinders
and
> instead it wanted to back fire through the intake a little and it
> wouldn't attempt to start as well as it did last night when I had
the
> coil hooked up to one cylinder. So I hooked up just the drivers
> cylinder and it fired up and ran on one cylinder, sounding much
like a
> Autopia car at Disneyland.
> So the good news is that I now can get it to run but only on one
> cylinder at a time until my replacement coil arrives.
> So can some explain this to me how it works?
> Thanks,
> Mike
> **************Looking for a car that's sporty, fun and fits in your
budget?
> Read reviews on AOL Autos.
> (
http://autos.aol.com/cars-Volkswagen-Je ... ert-review?
ncid=aolaut00030000000007 )
Re: Baffled by the ignition system
Mike, this may help you get your brakes up and working;
BRAKES 101;
It's a hydraulic system that compresses the fluid ( Department of transportation (dot)-3,4 or 5) in a captured cavity with sealed hydraulics so air does not get in. In order for it to work you need all systems to be sealed and not leaking or passing by. (fluid passing by the internal seals in the Master Cylinder will have an indication of weak or no peddle ) The Honda 600 has a dual Master Cylinder - this means that the front wheels are separate from the rear, it's a safety feature. This is why only the front are vacuum booster assisted (or power front disc brakes). So if you bleed the master cylinder before putting it into your car you can tell if it is leaking. If you want to check the hydraulic side of your power booster pull it and run a metal hydraulic line from the master cylinder (while it's out of the car) and using a few (very clean) bolts plug the other holes and see if it pumps up. (Place your fingers over the exit holes - Sedan has one, Coupe has two at the end of the piston shaft that bolts to the plate to the vacuum diaphragm on the aluminum units and out the end of the cast iron unit) push in on the Master Cylinder and see if the fluid can lift your finger held over the exit hole. If it does then it should work. (if it doesn't then there are problems in the booster) When you bleed your lines have a helper as has already been said or use a bleeder unit (see URL http://www.apexperformance.net/cartgeni ... sp?scat=26 ) is one, there are many of them out there. This one is fairly cheap.
Now bolt your booster and master cylinders back in place ( CAUTION: DOT-3 AND 4 WILL REMOVE PAINT IF YOU LET IT SET THERE FOR ANY AMOUNT OF TIME) So, rule of thumb keep every thing plugged while you put it back together and cover painted areas.
Dot 5, expensive, but it is inert - (will not absorb water, is nice to your seals and cylinders and lasts a very long time) Normally $5.00 to $7.00 a pint.
That said, and you have pulled every line apart and use compressed air to blow them out, (I use lacquer thinner to clean every metal part in the brake system, and blow it dry) Lacquer thinner will attack rubber, so clean your rubber with denatured alcohol.
Bolt everything back together and adjust the rear brakes as stated in the shop manual. (note if you have to change the vacuum hose DON'T USE JUST ANY OLD HOSE PURCHASE BOOSTER VACUUM HOSE) And, attach your bleeder to the bleed screw you want to start with (normally the one furthest away from the master cylinder) rear Left on the coupe and rear Right on the Sedan. Open the bleed screw and start pumping your brake peddle, very slowly so as not to cause air bubbles to form. I count to 10 on each downward push and 10 again on each upward motion. Every 5 or 6 full strokes check your master cylinder reservoir to make sure the fluid does not drain out. When you see fluid coming out the bleed tube attached to the bleeder valve on the rear wheel close it. Then move to the front left on the Coupe and front right on the Sedan, attach your bleeder to the bleed valve, open it and continue to pump the brakes. See fluid move to the other front wheel.
COMMON PROBLEM AREAS;
Problem - the brakes lock up, you open the bleed screw and let a few drops of fluid out and the wheels are free again. Step on the brake peddle a few times more and they are locked up again. One reason - The master cylinder has a bleed back hole in it (the small hole under the inlet at the top of the cylinder) I can send you a picture if you like. But if it's the back wheels it's the inlet marked on the master cylinder as R for rear. Front - F for yea, Front. Cause, the hole gets plugged over time (when left parked for a long time and it gets plugged up, some need a very small drill bit (use you fingers here) to un plug the small hole. Then the fluid will be released into the Master Cylinder reservoir.
Problem - everything seems to be working but your losing fluid. None of the wheels have a leak. it is most likely the seal on the piston to the vacuum booster letting fluid leak into the vacuum drum and on the other side of the vacuum diaphragm. You can tell by opening the rubber hose leading to the back side of the drum.
Unbolt it and see if any runs out.
This is a really simple run through of the brake system and some of the more common problems. If you pulled all your wheel cylinders and looked at them (note if the DOT-3 fluid has crystallized) If it has then open the bleed screw, remove the rubber cup's on the rear cylinders and the front and place them in a bucket of clear water for 30 minutes or so) This will liquefy the crystallized DOT-3 and allow the pistons to come out without damaging the seals. Normally if the fluid is crystallized then you will have to hone the cylinders. Because they are so small I use a length of rubber hose (about the same size as the inside diameter of the cylinder) warp 1000 grit wet sand paper around the rubber hose ONCE and make a couple of passes back and forth turning the hose as I move it in and out. If it becomes clean, great, if not the they will have to be sleeved in Brass or see Miles.
If it cylinder cleans up good, pull the rubber seals off the pistons and clean them up in water. Don't use carb or brake cleaners. Just clear water and the dip them in denatured alcohol and blow dry. Use DOT-3 or 4 or 5 to lube the inside of the cylinder and seal before re-assembly.
On the front disc brakes, clean everything, pull the cylinder out of the bracket and pull the pistons (CAUTION NOTE WHERE EVERY THING GOES SO YOU CAN PUT IT BACK TOGETHER - TAKE PICTURES IF NECESSARY) Make notes, draw pictures and use arrows to make sure your unit goes back together the same way. With the pistons out of the cylinder you will notice that there is only a rubber O ring on each end of the cylinder and the pistons are chromed. Look for pits in the chrome, pull the O rings and turn them inside out (why? Because instead of being round they are square and the inside edge runs along the piston while the outer edge is resting in the cylinder groove. Now the outer edge could be damaged too by rust or crystallized DOT-3 fluid. But maybe not and if you don't have new seals from Miles, then these might work.
CAUTION CAUTION CAUTION.....
You just put the brake system together, bleed the works and everything seems tight. Before you start driving this rocket down the road, try them out in the drive way. See if they stop the car. Turn off the engine, pump up the brakes and hold the the high hard peddle - now start the engine - the brake peddle should drop a 1/2 inch or so. This means the booster is working. Now hit the brakes a few times moving the car back and forth in the drive way. Stop, turn off the engine and check for leaks. If there are leaks they will show themselves. Then take it out on the local road, at slow speeds with your hand on the emergency brake. See how they work. If all is well, then the job is done. Remember "You get what you inspect not what you expect"
Have fun, be safe, ask questions.
Bill
BRAKES 101;
It's a hydraulic system that compresses the fluid ( Department of transportation (dot)-3,4 or 5) in a captured cavity with sealed hydraulics so air does not get in. In order for it to work you need all systems to be sealed and not leaking or passing by. (fluid passing by the internal seals in the Master Cylinder will have an indication of weak or no peddle ) The Honda 600 has a dual Master Cylinder - this means that the front wheels are separate from the rear, it's a safety feature. This is why only the front are vacuum booster assisted (or power front disc brakes). So if you bleed the master cylinder before putting it into your car you can tell if it is leaking. If you want to check the hydraulic side of your power booster pull it and run a metal hydraulic line from the master cylinder (while it's out of the car) and using a few (very clean) bolts plug the other holes and see if it pumps up. (Place your fingers over the exit holes - Sedan has one, Coupe has two at the end of the piston shaft that bolts to the plate to the vacuum diaphragm on the aluminum units and out the end of the cast iron unit) push in on the Master Cylinder and see if the fluid can lift your finger held over the exit hole. If it does then it should work. (if it doesn't then there are problems in the booster) When you bleed your lines have a helper as has already been said or use a bleeder unit (see URL http://www.apexperformance.net/cartgeni ... sp?scat=26 ) is one, there are many of them out there. This one is fairly cheap.
Now bolt your booster and master cylinders back in place ( CAUTION: DOT-3 AND 4 WILL REMOVE PAINT IF YOU LET IT SET THERE FOR ANY AMOUNT OF TIME) So, rule of thumb keep every thing plugged while you put it back together and cover painted areas.
Dot 5, expensive, but it is inert - (will not absorb water, is nice to your seals and cylinders and lasts a very long time) Normally $5.00 to $7.00 a pint.
That said, and you have pulled every line apart and use compressed air to blow them out, (I use lacquer thinner to clean every metal part in the brake system, and blow it dry) Lacquer thinner will attack rubber, so clean your rubber with denatured alcohol.
Bolt everything back together and adjust the rear brakes as stated in the shop manual. (note if you have to change the vacuum hose DON'T USE JUST ANY OLD HOSE PURCHASE BOOSTER VACUUM HOSE) And, attach your bleeder to the bleed screw you want to start with (normally the one furthest away from the master cylinder) rear Left on the coupe and rear Right on the Sedan. Open the bleed screw and start pumping your brake peddle, very slowly so as not to cause air bubbles to form. I count to 10 on each downward push and 10 again on each upward motion. Every 5 or 6 full strokes check your master cylinder reservoir to make sure the fluid does not drain out. When you see fluid coming out the bleed tube attached to the bleeder valve on the rear wheel close it. Then move to the front left on the Coupe and front right on the Sedan, attach your bleeder to the bleed valve, open it and continue to pump the brakes. See fluid move to the other front wheel.
COMMON PROBLEM AREAS;
Problem - the brakes lock up, you open the bleed screw and let a few drops of fluid out and the wheels are free again. Step on the brake peddle a few times more and they are locked up again. One reason - The master cylinder has a bleed back hole in it (the small hole under the inlet at the top of the cylinder) I can send you a picture if you like. But if it's the back wheels it's the inlet marked on the master cylinder as R for rear. Front - F for yea, Front. Cause, the hole gets plugged over time (when left parked for a long time and it gets plugged up, some need a very small drill bit (use you fingers here) to un plug the small hole. Then the fluid will be released into the Master Cylinder reservoir.
Problem - everything seems to be working but your losing fluid. None of the wheels have a leak. it is most likely the seal on the piston to the vacuum booster letting fluid leak into the vacuum drum and on the other side of the vacuum diaphragm. You can tell by opening the rubber hose leading to the back side of the drum.
Unbolt it and see if any runs out.
This is a really simple run through of the brake system and some of the more common problems. If you pulled all your wheel cylinders and looked at them (note if the DOT-3 fluid has crystallized) If it has then open the bleed screw, remove the rubber cup's on the rear cylinders and the front and place them in a bucket of clear water for 30 minutes or so) This will liquefy the crystallized DOT-3 and allow the pistons to come out without damaging the seals. Normally if the fluid is crystallized then you will have to hone the cylinders. Because they are so small I use a length of rubber hose (about the same size as the inside diameter of the cylinder) warp 1000 grit wet sand paper around the rubber hose ONCE and make a couple of passes back and forth turning the hose as I move it in and out. If it becomes clean, great, if not the they will have to be sleeved in Brass or see Miles.
If it cylinder cleans up good, pull the rubber seals off the pistons and clean them up in water. Don't use carb or brake cleaners. Just clear water and the dip them in denatured alcohol and blow dry. Use DOT-3 or 4 or 5 to lube the inside of the cylinder and seal before re-assembly.
On the front disc brakes, clean everything, pull the cylinder out of the bracket and pull the pistons (CAUTION NOTE WHERE EVERY THING GOES SO YOU CAN PUT IT BACK TOGETHER - TAKE PICTURES IF NECESSARY) Make notes, draw pictures and use arrows to make sure your unit goes back together the same way. With the pistons out of the cylinder you will notice that there is only a rubber O ring on each end of the cylinder and the pistons are chromed. Look for pits in the chrome, pull the O rings and turn them inside out (why? Because instead of being round they are square and the inside edge runs along the piston while the outer edge is resting in the cylinder groove. Now the outer edge could be damaged too by rust or crystallized DOT-3 fluid. But maybe not and if you don't have new seals from Miles, then these might work.
CAUTION CAUTION CAUTION.....
You just put the brake system together, bleed the works and everything seems tight. Before you start driving this rocket down the road, try them out in the drive way. See if they stop the car. Turn off the engine, pump up the brakes and hold the the high hard peddle - now start the engine - the brake peddle should drop a 1/2 inch or so. This means the booster is working. Now hit the brakes a few times moving the car back and forth in the drive way. Stop, turn off the engine and check for leaks. If there are leaks they will show themselves. Then take it out on the local road, at slow speeds with your hand on the emergency brake. See how they work. If all is well, then the job is done. Remember "You get what you inspect not what you expect"
Have fun, be safe, ask questions.
Bill
> -----Original Message-----
> From:
> anzhonda600owners@yahoogroups.com
> [mailto:anzhonda600owners@yahoogroups.com]
> On Behalf Of
> geez_tech
> Sent:
> Friday, August 15, 2008 1:44 PM
> To:
> anzhonda600owners@yahoogroups.com
> Subject:
> [anzhonda600owners] Re:
> Baffled by the ignition system
> Thanks Dale,
> That all makes a lot of sense, thanks for taking the time
> to
> explain it the way you did as I didn't think about the current taking
> the path with the least amount of resistance.
> Mike
> --- In
> anzhonda600owners@ yahoogroups. com
> ,
> goinhm@... wrote:
> > Hi Mike,
> > Here is some more
> info for you about why 1 coil did not work to
> fire both
> cylinders.
> > Someone else is calling the method used by the 600 as a
> wasted
> spark
> > ignition.... sounds
> > good to me. Both
> plugs are being sent high voltage at the same
> time and if
> > you
> have a dual
> > output ignition coil everything works fine. And when you > connect > the coil > > to one cylinder it worked ok > > on the one > cylinder. When you connected the output of the coil > to both
> cylinders, it did not work properly.
> > Why was that? Because one
> cylinder was at the top of its
> compression
> > stroke while the other
> cylinder was at the end of its exhaust
> stroke. When the
> > high
> voltage was applied to both cylinders from your coil, it > chooses the path
> > of least resistance which will be the side on the exhaust stroke.
> Your coil
> > is developing a voltage which keeps increasing until it
> can cause
> a spark in
> > the cylinders. The cylinder containing the
> spent exhaust gases
> probably
> > only needs a couple thousand volts
> to spark while the cylinder
> containing the
> > the air/fuel mixture
> under compression probably needs 10 to 15,000
> volts to
> > spark. So,
> the coil dumps its energy into the side with the
> exhaust gases and
> > now you have a cylinder full of air/fuel mixture
> > which has
> not ignited. When this cylinder is beginning its
> exhaust cycle it
> is under very little compression because the exhaust valve is > opening. Now
> > when your coil is ready to dump its energy, it sees a cylinder
> under
> > compression (full of air/fuel) and it sees another cylinder > under > very little > > compression (full of air/fuel because it did > not ignite on the > previous cycle). The > > cylinder which gets > ignited is the one requiring the lowest > voltage..... the > > cylinder > on its exhaust cycle. And since the cylinder is full of > air/fuel,
> it gets ignited.
> > Why is it backfiring through the intake?
> Normally the hot, spent
> exhaust
> > gases would be exiting through
> the exhaust port at high velocity
> when the
> > spark plug on this
> cylinder is fired. In your case, you have an
> air/fuel
> > mixture
> which has not been ignited which is being pushed out the > exhaust port at a
> > lower velocity when the spark plug ignites it. This causes an
> explosion of
> > the mixture which continues to burn as the exhaust
> valve closes
> and the intake
> > valve opens. The still burning
> mixture combines with the fresh
> intake
> > charge and you have
> combustion occuring on the intake stroke. You
> will hear the
> backfire through intake plus you may hear some popping in the > exhaust side
> > from that mixture being combusted.
> > BTW, when you
> look at the spark across your spark plug when it is
> outside
> > of
> the engine, the voltage at the plug is much lower than when it > gets placed
> > back into the engine. Outside of the engine, the spark plug is
> not under
> > compression and the coil only needs to develop a couple
> thousand
> volts to
> > jump the gap across the plug. Inside the engine
> and with the
> cylinder under
> > compression, the spark plug needs
> over 10,000 volts for the spark
> to jump the
> > gap. If your spark
> plug wires are defective, the ignition coil
> may be
> > dumping its
> energy between the plug wires and the engine chassis
> and not letting
> > the energy get to the spark plug. If your defective wiring has a
> breakdown
> > voltage of 3,000 volts, when you check the plug outside
> of the
> engine it looks
> > like it is working because you can see the
> spark at the plug (only
> 2,000
> > volts needed) but when the plug is
> installed in the engine and
> would need 10,000+
> > volts to make it
> spark, the energy instead goes into creating
> 3,000 volts
> > and
> letting the spark occur between the plug wire and the chassis.
> > Hope I didn't put you to sleep,
> > Dale
> > Ok, I'm confused here, even though the
> coil has two seperate spark
> plug
> > wires there is only one wire
> coming from the points and
> distributor
> > rotor to send spark to
> each cylinder, so how does each cylinder
> fire on
> > its own at
> different times?
> > Here is why I am asking, my thinking with this was
> that the coil
> always
> > fires both cylinders at the same time since
> there isn't a
> distributor
> > rotor for this and both plug wires come
> out of the same coil
> housing,
> > so I tried to hook up my VW coil so
> it could fire both cylinders
> and
> > instead it wanted to back fire
> through the intake a little and it
> > wouldn't attempt to start as well
> as it did last night when I had
> the
> > coil hooked up to one
> cylinder. So I hooked up just the drivers
> > cylinder and it fired up
> and ran on one cylinder, sounding much
> like a
> > Autopia car at
> Disneyland.
> > So the good news is that I now can get it to run but only > on one > > cylinder at a time until my replacement coil arrives.
> So can some explain this to me how it works?
> > Thanks,
> Mike
> ************ **Looking for a car that's sporty, fun and fits in your
> budget?
> > Read reviews on AOL Autos.
> > (
> http://autos. aol.com/cars- Volkswagen- Jetta-2009/ expert-review?
> ncid=aolaut00030000 000007
> )
-
mygto_1999
- Posts: 1
- Joined: Sat Jun 22, 2002 8:00 am
Re: Baffled by the ignition system
Thanks Bill!
I hope that was a copy and paste from helping others with brake issues as that was lengthy and very informative, thanks for putting that together. I have saved it as document now and also printed it for when I get going on my brake system. I’m spraying my fittings and bleed screws with PB Blaster to help with the rust, hopefully it soaks in good so nothing breaks off, especially the bleed screws as this was also a common issue with my air cooled VW’s.
Mike
I hope that was a copy and paste from helping others with brake issues as that was lengthy and very informative, thanks for putting that together. I have saved it as document now and also printed it for when I get going on my brake system. I’m spraying my fittings and bleed screws with PB Blaster to help with the rust, hopefully it soaks in good so nothing breaks off, especially the bleed screws as this was also a common issue with my air cooled VW’s.
Mike