Coil pack conundrum!
Discussion
Looking for some technical help with this one. I have had 3 coil packs fail on me this year, No3 and two No1s. Car is 03 WRX Blob modded to 340hp and I have no idea why these keep failing. Its that bad now that I have lost some confidence on long drives as if it fails again (like it did in North Wales, 4 hours from home) I am buggered.
Looking into replacements I am also confused as the packs have different part no's. Are these simply due to different manufacturer or different ratings?
Have been told to buy the Plasma Projects upgrade packs but I am loathe to fork out £400 without knowing what the issue is, worse case scenario is i buy the upgrade and it does the same thing.
Any techies out there?
Looking into replacements I am also confused as the packs have different part no's. Are these simply due to different manufacturer or different ratings?
Have been told to buy the Plasma Projects upgrade packs but I am loathe to fork out £400 without knowing what the issue is, worse case scenario is i buy the upgrade and it does the same thing.
Any techies out there?
So long as Ignition Dwell (part of ECU mapping) hasn't been touched there should be no reason why your coil packs keep packing up. If you have replaced them and it's doing it again then it could be something in the engine loom.
Are your cars earth cables in good condition, bolted to where they should be, and clear of any corrosion.
Is your car standard?, and do you know if it's been mapped?
Which spark plugs are you using? Plugs with a high resistance can cause coil packs to become faulty.
Would be worth getting the supply loom checked out for any shorts and supply voltages.
Is your alternator OK and not over charging? Get it checked for any over/under-voltage issues.
Are the coil packs bolted down properly after fitting. Is the spark plug sleeve properly located over and onto the spark plug. Are you seeing any sparks jumping from the coil packs or sleeves (cracked casings) to the cylinder head or are you getting any electrical shocks from said components when the engine is running.
If you get everything checked and it's all OK, rather than keep buying Subaru standard coil packs get after market upgraded coil packs that can handle a lot more voltage/current/heat. Try an earthing kit as well. A bad earth can cause anything form starting problems to general running issues under light or heavy loads not to mention lighting/battery problems.
Are your cars earth cables in good condition, bolted to where they should be, and clear of any corrosion.
Is your car standard?, and do you know if it's been mapped?
Which spark plugs are you using? Plugs with a high resistance can cause coil packs to become faulty.
Would be worth getting the supply loom checked out for any shorts and supply voltages.
Is your alternator OK and not over charging? Get it checked for any over/under-voltage issues.
Are the coil packs bolted down properly after fitting. Is the spark plug sleeve properly located over and onto the spark plug. Are you seeing any sparks jumping from the coil packs or sleeves (cracked casings) to the cylinder head or are you getting any electrical shocks from said components when the engine is running.
If you get everything checked and it's all OK, rather than keep buying Subaru standard coil packs get after market upgraded coil packs that can handle a lot more voltage/current/heat. Try an earthing kit as well. A bad earth can cause anything form starting problems to general running issues under light or heavy loads not to mention lighting/battery problems.
Edited by ScoobieWRX on Tuesday 13th November 12:24
Are your cars earth cables in good condition, bolted to where they should be, and clear of any corrosion.
Is your car standard?, and do you know if it's been mapped?
Which spark plugs are you using? Plugs with a high resistance can cause coil packs to become faulty.
Would be worth getting the supply loom checked out for any shorts and supply voltages.
Is your alternator OK and not over charging? Get it checked for any over/under-voltage issues.
Are the coil packs bolted down properly after fitting. Is the spark plug sleeve properly located over and onto the spark plug. Are you seeing any sparks jumping from the coil packs or sleeves (cracked casings) to the cylinder head or are you getting any electrical shocks from said components when the engine is running.
If you get everything checked and it's all OK, rather than keep buying Subaru standard coil packs get after market upgraded coil packs that can handle a lot more voltage/current/heat. Try an earthing kit as well. A bad earth can cause anything form starting problems to general running issues under light or heavy loads not to mention lighting/battery problems.
[/quote]
Wow,
that has to be the most comprehensive and best reply to a thread I have posted, ever. many thanks for your time and advice. Posted up on SNet a while back with no real response.
Will check the earths this weekend, are they easy to find? I do have the servicing manual so hopefully they are detailed in there.
Far from standard, albeit the normal WRX mod route of:
VF35
STi Intercooler
550 pinks
Walbro pump
SPT intake
decat up pipe
Prodrive downpipe
Prodrive mid pipe
Prodrive back box
Blitz cold grade 7 plugs (iirc)
and remap by Duncan of RaceDynamix.
Will try to get all the other bits checked over the coming week or two. I am using 2nd coil packs from Rowleys in Cullompton at £40 a go so not breaking the bank yet. The real pain is trying to limp home on 3 cylinders when i dies on me. Last time had to get it low loaded from Chester to Somerset!
Is your car standard?, and do you know if it's been mapped?
Which spark plugs are you using? Plugs with a high resistance can cause coil packs to become faulty.
Would be worth getting the supply loom checked out for any shorts and supply voltages.
Is your alternator OK and not over charging? Get it checked for any over/under-voltage issues.
Are the coil packs bolted down properly after fitting. Is the spark plug sleeve properly located over and onto the spark plug. Are you seeing any sparks jumping from the coil packs or sleeves (cracked casings) to the cylinder head or are you getting any electrical shocks from said components when the engine is running.
If you get everything checked and it's all OK, rather than keep buying Subaru standard coil packs get after market upgraded coil packs that can handle a lot more voltage/current/heat. Try an earthing kit as well. A bad earth can cause anything form starting problems to general running issues under light or heavy loads not to mention lighting/battery problems.
Edited by ScoobieWRX on Tuesday 13th November 12:24
[/quote]
Wow,
that has to be the most comprehensive and best reply to a thread I have posted, ever. many thanks for your time and advice. Posted up on SNet a while back with no real response.
Will check the earths this weekend, are they easy to find? I do have the servicing manual so hopefully they are detailed in there.
Far from standard, albeit the normal WRX mod route of:
VF35
STi Intercooler
550 pinks
Walbro pump
SPT intake
decat up pipe
Prodrive downpipe
Prodrive mid pipe
Prodrive back box
Blitz cold grade 7 plugs (iirc)
and remap by Duncan of RaceDynamix.
Will try to get all the other bits checked over the coming week or two. I am using 2nd coil packs from Rowleys in Cullompton at £40 a go so not breaking the bank yet. The real pain is trying to limp home on 3 cylinders when i dies on me. Last time had to get it low loaded from Chester to Somerset!
I wonder if Duncan has altered the Ignition Dwell calibration and upped it to a point where your WRX coil packs don't like it.
That could certainly cause your coil packs to pack in after a while, especially under hard use if it's too high. It might be worth getting hold of a set of STi Coil Packs. Simon (JGM) reckons the WRX ones are identical to the STi ones, just different casings. I don't disbelieve him at all and he's had them apart however, you just never know.
I run quite a bit of ignition dwell on my coil packs and they have been just fine under all conditions, although i do use STi coil packs and i run an STi engine in my WRX wagon.
I've just had a look at the mapping for WRX and STi of your year and the STi ignition dwell is set to almost double what the WRX dwell is. To make absolutely sure i might go for a set of the heavy duty after market coil packs. If you burn a set of those out then you have got a serious issue there somewhere.
Without plugging in to your ECU it's hard to tell if it's something in the mapping or perhaps you have a wiring/electrical issue.
Did you get your 550cc injectors cleaned and checked for flow in an ultrasonic cleaner together with a before and after report??
If one or two of your injectors are running a bit short on flow they will run lean. Running lean means you run too hot. Running too hot means you could end up melting a spark plug or two. As the plugs get hotter their coil resistance rises and they need more of a charge/higher voltages to create a good spark, and prolonged operation under those conditions means you will eventually kill a coil pack or two as you have already done.
There is also a danger of detonation/knock if you run those cylinders that lean/hot, and even though the wideband that was used to tune your car might read the engine is fuelling ok, two or three of those injectors could be running rich enough and you won't necessarily know you have a problem elsewhere. The only way to know if each cylinder is fuelling spot is to run a wideband on each exhaust manifold branch and not many people do that these days unless you're in high end motorsport. The impreza has a cylinder that runs leaner than the rest (no.3) because it's last in line for fuel and you generally find if there are cylinder issues on the impreza it's generally no.3 that plays up. I modified my 550cc injectors and had them cleaned and flow checked. I had 3 running at 852cc and one running at 844cc. I've mapped all my injectors to run at around 844cc and modified the fuel rail to run parallel so all the injectors get fuelled equally. Suffice to say and without running 4 widebands fuelling is spot on.
Go back to Duncan and get him to check the car out with his equipment and see if he can find anything. He might be able to cast some light on your dying coil pack issues. If you can't get hold of Duncan (he is busy) or find yourself over Northampton way sometime let me know. If i'm available i'll happily plug in and take a look.
That could certainly cause your coil packs to pack in after a while, especially under hard use if it's too high. It might be worth getting hold of a set of STi Coil Packs. Simon (JGM) reckons the WRX ones are identical to the STi ones, just different casings. I don't disbelieve him at all and he's had them apart however, you just never know.
I run quite a bit of ignition dwell on my coil packs and they have been just fine under all conditions, although i do use STi coil packs and i run an STi engine in my WRX wagon.
I've just had a look at the mapping for WRX and STi of your year and the STi ignition dwell is set to almost double what the WRX dwell is. To make absolutely sure i might go for a set of the heavy duty after market coil packs. If you burn a set of those out then you have got a serious issue there somewhere.
Without plugging in to your ECU it's hard to tell if it's something in the mapping or perhaps you have a wiring/electrical issue.
Did you get your 550cc injectors cleaned and checked for flow in an ultrasonic cleaner together with a before and after report??
If one or two of your injectors are running a bit short on flow they will run lean. Running lean means you run too hot. Running too hot means you could end up melting a spark plug or two. As the plugs get hotter their coil resistance rises and they need more of a charge/higher voltages to create a good spark, and prolonged operation under those conditions means you will eventually kill a coil pack or two as you have already done.
There is also a danger of detonation/knock if you run those cylinders that lean/hot, and even though the wideband that was used to tune your car might read the engine is fuelling ok, two or three of those injectors could be running rich enough and you won't necessarily know you have a problem elsewhere. The only way to know if each cylinder is fuelling spot is to run a wideband on each exhaust manifold branch and not many people do that these days unless you're in high end motorsport. The impreza has a cylinder that runs leaner than the rest (no.3) because it's last in line for fuel and you generally find if there are cylinder issues on the impreza it's generally no.3 that plays up. I modified my 550cc injectors and had them cleaned and flow checked. I had 3 running at 852cc and one running at 844cc. I've mapped all my injectors to run at around 844cc and modified the fuel rail to run parallel so all the injectors get fuelled equally. Suffice to say and without running 4 widebands fuelling is spot on.
Go back to Duncan and get him to check the car out with his equipment and see if he can find anything. He might be able to cast some light on your dying coil pack issues. If you can't get hold of Duncan (he is busy) or find yourself over Northampton way sometime let me know. If i'm available i'll happily plug in and take a look.
Duncan may just be very busy, or didn't get your email. You should have a look over at his Facebook page see if you can message him from there.
If you still get no joy my offer is still there but you will have to come over to Northampton as my bill to travel to your neck of the woods wouldn't be cheap even if i did the diagnosis FOC. Alternatively there must be another scooby specialist your neck of the woods that can plug in, take the car out and have a proper look at what it's doing on the move.
Don't know what else to suggest.
If you still get no joy my offer is still there but you will have to come over to Northampton as my bill to travel to your neck of the woods wouldn't be cheap even if i did the diagnosis FOC. Alternatively there must be another scooby specialist your neck of the woods that can plug in, take the car out and have a proper look at what it's doing on the move.
Don't know what else to suggest.
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