[jordanlen]

I agree and I asked them not to change the plugs as where less than 5 months old and £26 each but they did anyway🤷🏼. How do you test a coil? These was the coils the independent garage fitted because they give me the old ones back in this box

 

[jordanlen]

Is it common for Suzukis to be sensitive to aftermarket parts? I’ve had a friend that had issues with non genuine abs sensors on a Mercedes but I’m not a mechanic and my garage used after market parts and I didn’t think to question it

 

[2013GV]

Is it common for Suzukis to be sensitive to aftermarket parts? I’ve had a friend that had issues with non genuine abs sensors on a Mercedes but I’m not a mechanic and my garage used after market parts and I didn’t think to question it

Cheap Aftermarket often don't have the quality control. Reputable aftermarket usually does.
You gets what you pays for. Ask anybody thats bought 4 fuel injectors for the price of one genuine oem one.

 

[aquanaut20]

The coils are tested with a scope on the primary (amp clamp) and secondary( (induction pickup), that will produce a wave form, which provides a multitude of valuable data,

how to test a cop with a scope - Bing video

 

[aquanaut20]

Similar tests for injectors..

 

[jordanlen]

Thanks for your input guys and I will post a update in a few weeks to let you know if the fault returns

 

[Vitara NZ]

I've just fixed the coil problem on my Vitara after putting up with intermittent misfire for some time now. I fitted the Honda K20A stick coils and modified the wiring to suit. (I see they had been fitted in Mitsubishi vehicles as well) After looking online I found 2 options one was the K20A Coils and the other was the LS2-3 coils and leads. The LS2 coils can draw as much as 10amps per coil this would require a relay and power source from the battery and the Honda coils only draw around 3.6amps each, 7 amps for the 2 coils the ignition circuit has a 20 amp fuse no problem so far.
The P0420 code would come up occasionally but disconnecting the battery for 30 seconds soon fixed that. No reoccurrence of that so far.

Performance change is like chalk and cheese I've had the vehicle for 100,000 Kms and can say it is going as good or better than when it was new. You can now drive around town in 3rd and 4th gear again with no misfires as you slow down and speed up in traffic.

 

[2013GV]

I've just fixed the coil problem on my Vitara after putting up with intermittent misfire for some time now. I fitted the Honda K20A stick coils and modified the wiring to suit. (I see they had been fitted in Mitsubishi vehicles as well) After looking online I found 2 options one was the K20A Coils and the other was the LS2-3 coils and leads. The LS2 coils can draw as much as 10amps per coil this would require a relay and power source from the battery and the Honda coils only draw around 3.6amps each, 7 amps for the 2 coils the ignition circuit has a 20 amp fuse no problem so far.
The P0420 code would come up occasionally but disconnecting the battery for 30 seconds soon fixed that. No reoccurrence of that so far.

Performance change is like chalk and cheese I've had the vehicle for 100,000 Kms and can say it is going as good or better than when it was new. You can now drive around town in 3rd and 4th gear again with no misfires as you slow down and speed up in traffic.

Be aware that you may be overloading the drive transistors in the ecm. Pop those and you have big problems. The coil packs fitted to the Suzuki’s are matched to the drivers.

 

[Vitara NZ]

Thanks 2013GV, after cutting open one of the old OEM coils its my understanding that the coils are fitted with a Darlington Transistor (commonly known as a igniter unit in the old days) and that the drive transistors in the ECM are only putting out a 5 volt switching signal and that all the current and load is controlled inside the coil. You can test these coils on the bench with a 12 volt and 5 volt power supply flicking the 5 volts onto the correct terminal to make them spark once you have plugs and leads set up.
Any knowledge and advise respectfully accepted.

 

[2013GV]

Yep, that's correct, the high power coil driver is built into the pack in the 3 wire systems. The bigger issue is the current the drive transistor in the ecm has to sink to trigger the driver Darlington in the coil. Check the drive current requirements on the Darlington to see how much base current is required to drive it into saturation. ( ie fully turn it on immediately) you might be surprised just how much they need.
The ecm doesn't put out 5V, it switches the Darlington base to turn it on, that involves current. Effectively you have a small power transistor driving a bigger one, its that smaller one you run the risk of overloading.

 

[Vitara NZ]

To be fair I am not the first person to do this. I was going to use Toyota waste spark coils and leads but the Honda coils where the cheapest option. Both the Toyota and Honda coils as well as the Suzuki coils use a Positive 5 Volt signal input to trigger. The Darlington transistors are available in both NPN & PNP configuration the above was just an example. Not sure where you are coming from an automotive or electronics back ground but here is an extract from the OEM workshop manual for the M16A engine.

 

[2013GV]

You are confusing voltage with current. The ecm has to supply a trigger voltage high enough and with enough current flow to cause the coil to fire. Its that current flow to cause the coil to fire that damages the ecm driver transistors
Just saying its a 5V pulse is only 1/2 the actual story.

I am looking at this from both an automotive and electronics perspective.

 

[Vitara NZ]

2013GV so can you actually help with trigger current data and specs for say the M16A waste spark coil and the COP on the J24B engine
Cheers

 

[2013GV]

I can try and find some specs, ill see if I have any data in the fsm

 

[fkrlnzm75]

Hello All,

First time poster, long time lurker. Would love some advice on this one please.

My wife’s Swift is driving me crazy. It is a 2005 Swift with 125KM on the clock. I have had ongoing misfire problems for the past 6 months. I have also had a recurring P0420 code.

After replacing the pre-cat o2 sensor the P0420 was resolved.

The intermittent and repeated misfire was initially diagnosed as a faulty coil. You could see where the spark was arcing out of the coil. All coil packs, leads and plugs were replaced. Issue went away for a couple of months.

Misfire returns. Same symptoms, intermittent misfire, no CEL, only under load. Mechanic said they had a bad batch of coils and replaced again. Also put new Iridium plugs in. No misfire for a couple of days. But then returns.

Also a P0108 CEL code appears. Data shows that the manifold pressure when the CEL went on was 118KPA (probably about the atmospheric pressure). Car is running fine otherwise so I clear the code and it sensor is reading normal (about 35KPA when idle or 100KPA when turned off with key on).

Next visit to mechanic, coils inspected and appear fine. Mechanic replaces cam angle sensor. A couple of days later and it is still missing intermittently but only when cold. Take to mechanic but it was running perfectly.

Where it is at now. About every few days, when the car is started (when engine is cold), it shakes and shudders like mad and loses revs to the point of almost stalling. It only corrects itself after revving it up a few times. It then drives with a bad misfire, bunny hopping under load, for the first KM or so until warm. It then runs perfect, really well in fact. When I plug in scanner immediately it shows misfire in various cylinders and random misfire. I have attached the freeze frame data from one of the recent episodes.

What could be the cause of the most recent issue?

Appreciate any thoughts on this as the mechanic is also scratching his head.

Check if any loose connection with coil pack connector. If there is a freeplay at it, just change it.
Then check your FICD switch. If multimeter shows low resistance change it but if the resistance is too low, change FICD + IACV

I am not well versed in it but I have the same problem with my wife's swift RS415 and read it somewhere on intermittent misfires when idling.

In the coming days, I'll go to wireman and repairer to try the solution. Hope it works

 

[Vitara NZ]

K20A Honda Coils in a M16A engine
Silence well done, if you do the same thing, the same way, you get the same result.
small power transistor driving a bigger one
That is exactly what a Darlington transistor is, all located in the ignition coil. In fact the maximum trigger current that the transistor can handle is 1 Amp and nominally runs at 30mAmps in milliseconds with a changing voltage which alters the dwell of the coil.
I think you will find that the engine ECU is a bit more robust than you give it credit for. It must have internal safety circuits for wiring dead shorts and open circuits given the rate of Suzuki M engine ignition coil failures the ECU manufacturers wouldn't be able to keep up.
FSM does that mean Factory Service Manual = OEM of which I have at 1730 odd pages and have read all the relevant pages and found nothing on the trigger circuit currant draw only voltage. You may see more information on the Suzuki diagnostic tool, my OBD11 doesn't show anything that detailed.
And the smoke is still in the box time will tell if it gets out.
Anyway its been a done deal for some time now starts better drives better and pulls up hills better
S/H coils are really cheap 30 NZ$ each, coil plugs 25 NZ$ for set of 4 and a bit of time for those with the will. I fitted a bit of 6.5mm felt to the top of the coils and the cover slightly modified with a heat gun and dremel to make clearance around the front retaining bolts ( note 2 coils have had there original mounts cut off) the cover holds the coils firmly in place as can be seen on the #2 coil with the in print of the H from DOHC on the cover.