Honda Jazz jerking and not accelerating well

[culzean]

Normally it is when rear plugs get left in too long and gap gets big that it stresses the coil insulation ( the coil pack has develop more voltage to jump the widening gap in plugs ) and causes failure.  We had a few MK1's and plugs were all replaced on time or early and never had a problem with rear coils.  I don't think coils are intrinsically unreliable - but it is a chain of events, the rear coils run in more heat than front coils because they are next to exhaust manifold and if plugs are neglected the extra heat makes them more likely to fail than front ones.

[onurm]

Normally it is when rear plugs get left in too long and gap gets big that it stresses the coil insulation ( the coil pack has develop more voltage to jump the widening gap in plugs ) and causes failure.  We had a few MK1's and plugs were all replaced on time or early and never had a problem with rear coils.  I don't think coils are intrinsically unreliable - but it is a chain of events, the rear coils run in more heat than front coils because they are next to exhaust manifold and if plugs are neglected the extra heat makes them more likely to fail than front ones.

So you think it is worth trying to replace the ignition coils? I had the spark plugs replaced and didn’t make a difference but it could have affected the coils since it looked like the rear plugs hadn’t been replaced in about 3 years

[onurm]

Could it be the rear banks of ignition coils failing it's quite common on Jazz's of that age regardless of mileage covered and sometimes does not show up as a fault codes at all. It happened to both of my cvt Jazzes one at approx 55k the other at 75k. After replacing all 4 rear coils on both cars respectively jerking (it was intermittent) disappeared completely. The CVT gearbox is pretty trouble free with the exception of judder on take off which normally can be eliminated with a gearbox oil change/flush and a shot of XADO 120

Mine happens at intermittent intervals as well. It doesn’t happen at every gear change which is why I’m questioning if the problem isn’t actually the gearbox. Also mine is at 54k miles as well. Do you think it is worth trying?

[onurm]

Could be worth a pop. Something like this maybe.
https://www.ebay.co.uk/itm/Honda-Jazz-Mk2-2002-2008-1-3-Set-Of-8-Coil-Pack-Coil-Packs/193517540136?hash=item2d0e8b5328:g:VX8AAOSwyz5e0-u8

Or "Buy Now"
https://www.ebay.co.uk/itm/Honda-Jazz-Mk2-2002-2008-1-3-Set-Of-8-Coil-Pack-Coil-Packs/224045345913?hash=item342a24ac79:g:e1oAAOSwP1de5kmS

This is great! Is it a difficult job to do by myself? Or do you think I should leave it to a garage? I keep spending money but not coming to a resolution so I’m hoping this could solve it

[springswood]

I've done this job. It's a bit fiddly at times with the rear ones but not too difficult.

[culzean]

Could be worth a pop. Something like this maybe.
https://www.ebay.co.uk/itm/Honda-Jazz-Mk2-2002-2008-1-3-Set-Of-8-Coil-Pack-Coil-Packs/193517540136?hash=item2d0e8b5328:g:VX8AAOSwyz5e0-u8

Or "Buy Now"
https://www.ebay.co.uk/itm/Honda-Jazz-Mk2-2002-2008-1-3-Set-Of-8-Coil-Pack-Coil-Packs/224045345913?hash=item342a24ac79:g:e1oAAOSwP1de5kmS

This is great! Is it a difficult job to do by myself? Or do you think I should leave it to a garage? I keep spending money but not coming to a resolution so I’m hoping this could solve it

it is a lot easier than doing the plugs, you have to take coils packs off to get access to plugs anyway ( and then do the plugs, which on the rear is the hardest bit ),  and the coil packs only attached to car wiring by small plugs that are easy to unplug.  As long as you remember all the fronts are identical fixing and all rears identical ( but not interchangeable between front and rear - IIRC rears are shorter and fixing screw hole in different place ) -

The coil pack is held in place with a 5 or 6mm hex head screw, Just remember that on car electrical plugs there is always a 'catch' of some kind to stop plug from falling out of socket,  this is normally a ridged bit sticking up that you have to press down to raise a clip to release plug from socket - plugging them back in you don't need to press the clip and there is normally a 'click' as the clip drops back into its recess.

[Jocko]

looked like the rear plugs hadn’t been replaced in about 3 years

Mine haven't been replaced in three years either (front or rear), but they are due to be changed next service.

[onurm]

Could be worth a pop. Something like this maybe.
https://www.ebay.co.uk/itm/Honda-Jazz-Mk2-2002-2008-1-3-Set-Of-8-Coil-Pack-Coil-Packs/193517540136?hash=item2d0e8b5328:g:VX8AAOSwyz5e0-u8

Or "Buy Now"
https://www.ebay.co.uk/itm/Honda-Jazz-Mk2-2002-2008-1-3-Set-Of-8-Coil-Pack-Coil-Packs/224045345913?hash=item342a24ac79:g:e1oAAOSwP1de5kmS

This is great! Is it a difficult job to do by myself? Or do you think I should leave it to a garage? I keep spending money but not coming to a resolution so I’m hoping this could solve it

it is a lot easier than doing the plugs, you have to take coils packs off to get access to plugs anyway ( and then do the plugs, which on the rear is the hardest bit ),  and the coil packs only attached to car wiring by small plugs that are easy to unplug.  As long as you remember all the fronts are identical fixing and all rears identical ( but not interchangeable between front and rear - IIRC rears are shorter and fixing screw hole in different place ) -

The coil pack is held in place with a 5 or 6mm hex head screw, Just remember that on car electrical plugs there is always a 'catch' of some kind to stop plug from falling out of socket,  this is normally a ridged bit sticking up that you have to press down to raise a clip to release plug from socket - plugging them back in you don't need to press the clip and there is normally a 'click' as the clip drops back into its recess.

Shall I try replacing the ignition coils then before bringing it to Honda?

I haven’t got a check engine light or any problems with my car failing to start just the jerking and the problem at high rpm

[onurm]

looked like the rear plugs hadn’t been replaced in about 3 years

Mine haven't been replaced in three years either (front or rear), but they are due to be changed next service.

Yeah so I had all 8 changed but I’m wondering if the back 4 might have affected the coil packs because they hadn’t been changed?

[culzean]

it looked like the rear plugs hadn’t been replaced in about 3 years

It is mainly about mileage with spark plugs because every time a spark happens it burns a bit of the electrode material away and widens the gap,  that is why iridium plugs last a lot longer as the iridium ( or platinum) is a lot more resistant to the spark erosion than copper alloy or steel,  especially at high temperature.  The extra electrical resistance of the iridium makes no difference as the plugs already have a 5000 ohm resistor in the body ( the R in plug number ) for electrical noise suppression and the voltage is so high ( 15,000 to 30,000 volts ).

https://haynes.com/en-gb/tips-tutorials/simple-guide-your-cars-ignition-coil-pack

quote from article linked...

However, the primary cause of coil failure is voltage overload caused by worn spark plugs with electrode gaps that are outside specified limits or by damaged cabling and wires.

[onurm]

it looked like the rear plugs hadn’t been replaced in about 3 years

It is mainly about mileage with spark plugs because every time a spark happens it burns a bit of the electrode material away and widens the gap,  that is why iridium plugs last a lot longer as the iridium ( or platinum) is a lot more resistant to the spark erosion than copper alloy or steel,  especially at high temperature.  The extra electrical resistance of the iridium makes no difference as the plugs already have a 5000 ohm resistor in the body ( the R in plug number ) for electrical noise suppression and the voltage is so high ( 15,000 to 30,000 volts ).

https://haynes.com/en-gb/tips-tutorials/simple-guide-your-cars-ignition-coil-pack

quote from article linked...

However, the primary cause of coil failure is voltage overload caused by worn spark plugs with electrode gaps that are outside specified limits or by damaged cabling and wires.

So would you suggest me trying to change the coils first to try resolve this problem?

[culzean]

it looked like the rear plugs hadn’t been replaced in about 3 years

It is mainly about mileage with spark plugs because every time a spark happens it burns a bit of the electrode material away and widens the gap,  that is why iridium plugs last a lot longer as the iridium ( or platinum) is a lot more resistant to the spark erosion than copper alloy or steel,  especially at high temperature.  The extra electrical resistance of the iridium makes no difference as the plugs already have a 5000 ohm resistor in the body ( the R in plug number ) for electrical noise suppression and the voltage is so high ( 15,000 to 30,000 volts ).

https://haynes.com/en-gb/tips-tutorials/simple-guide-your-cars-ignition-coil-pack

quote from article linked...

However, the primary cause of coil failure is voltage overload caused by worn spark plugs with electrode gaps that are outside specified limits or by damaged cabling and wires.

So would you suggest me trying to change the coils first to try resolve this problem?

At the price in Jocko link for a full set I would definitely go that route.  Those coil packs are cheaper than the spark plugs..  at worst you end up with some spare coil packs..

The coils in one of those ebay offers end in about 4 hours

[onurm]

Problem solved!

Catalytic converter & back box replaced. Car drives perfectly.

[Jocko]

Great stuff. I'll file that for future reference.

madasafish suggested that a few weeks back.