You do not need a Suzuki specialist, all ICE (internal combustion engines work the same, suck, squeeze, bang and blow.. If it miss fires one of those is out of sync.. NOT rocket science.. It just need to be properly diagnosed, not just guessing and throwing parts..

What is your skill level ?
What tool/equipment do you have available ?
Are you interested in getting it fixed, or are you relying on those mechanics..?

 

Hi thanks again for replying. why would the car judder and hunt for revs at low rpm but when you go above 3000 rpm drive completely fine? as per skill level, I can service, change parts and brake pads ect . I do have a obd link mx+ scanner but it wasn’t giving me any codes. I don’t have experience with reading perimeters but could learn. I obviously didn’t want to pay main dealers prices but I thought be best to go, sort of run out of ideas. it was my grandfather cars but he’s not driving no more as he’s got dementia so it does have a lot of sentimental value. I’m in south wales if you know of any specialists. it’s an 08 with 77,000 miles on the clock, run on the super unleaded. Full Suzuki service history up 2020 then local garage since. It had a new subframe, radiator and a/c condenser last year. Always stayed on top maintenance but this fault has been to 4 different garages.

 

Haven't been in S.Wales since 1956,

This would require at the very least a scanner that has graphing capabilities. Some thing that can perform an engine balance test..

 

I don’t think much as changed since then 😅. It had around 40,000 on the clock when we got it. It’s never used a drop of oil. are the 1.6 engines temperamental? I did read that they can be sensitive to plug gaps ?

 

Remember that not all misfires are ignition related, they can be fuel related. 1 sticky injector will, throw a p0300 code as well.

 

Yes, I would be running an amp clamp on the coils and injectors, if I see an anomaly will chase that.

 

Went to School in in Mountain Ash, and lived between MT A. and Abercynon.

Dad was R Navy and we were posted to the Med from S.Wales..

 

I'm thinking a sticky injector on close, or slow opening, look for pintle bump and rise time with a scope

 

I dont think he has access to a scope, seems neither do the Indy's nor dealer..

 

Bugger....not much choice then, find a diagnostician

 

I lived in abercynon until 3 years ago. Caerphilly now. I will be collecting the car from the Suzuki garage later, they phoned me yesterday and the fitter is trying a few things, so I should find out later if they have any more info. the last garage I used was supposed to be a diagnostic guy and he said the only thing he picked up on was there was a lot of load on the alternator and he wanted to replace the alternator with a genuine Suzuki which was about £450 plus labour and that’s when I put it into the Suzuki garage as he said it was a guess.

what is a scope? And how does it work?

 

How Does an Oscilloscope Work? – The Ultimate Guide! (oscilloscopetools.com)

Old article but still relevant.

 

So today I picked the car up from Suzuki, it had new coils, plugs and leads. so far no miss fire or juddering below 3000rpm. I drove it around 20 miles mixture of city and country lanes. They said they think the coils was the issues even tho they where new but not genuine Suzuki part was causing the issues. I hope this has cured it. I will keep you guys updated.

 

They said they think the coils was the issues even tho they where new but not genuine Suzuki part was causing the issues. I hope this has cured it. I will keep you guys updated.

Just love the way they guess, no solid test to state that was the issue..

But good luck..!

 

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

 

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.

 

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

 

Similar tests for injectors..

 

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

 

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.

 

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.

 

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.

 

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.

 

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.

 

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

 

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