[s-cars] Checking for spark

[tedebearp at yahoo.com]

Thanks for the comments.  Actually the UrS4 is running well, although it sometimes seemed to "level out" under full throttle.  It wasn't a sharp drop in power so I wasn't sure it was a "miss".  I had misfires from a shop installing the wrong spark plugs and that was very obvious.  I think it might be the stock fuel pump not quite keeping up with demand (MTM stage II+ chip and GT2871 hybrid turbo). 

My question was prompted my wife's E46 (BMW) 330i that won't start.  At first I thought it was the battery, but the battery passed the load test at the FLAPS and is fully charged.  The engine seems to be getting fuel, judging by the smell of fuel at the tailpipe after unsuccessful attempts to start it.

What's the advantage of using a spark plug tester instead of just removing the spark plug, connecting the coil pack to it, and using a battery jumper cable clamped on the spark plug base to ground it?  I have no problem with buying the spark plug tester - just don't want to wait for it to show up.  The only spark plug testers I can find in the store are the inline kind and I hear they're not very good at diagnosing a weak ignition coil.

I don't think I have a weak ignition coil as there are six coils (unlikely they all failed at once) and the engine doesn't even catch when trying to start it.  The tachometer needle moves, which makes me think it's not the crankshaft position sensor.

Sent from my iPad

> On Jan 26, 2016, at 12:23 PM, Mike Miller <mikemilr at blackfoot.net> wrote:
> 
> I have used that one to test the LS2 coils and the wires on my UrS6. It picked off 1 weak coil and 2 marginal wires. Stumbling issues solved.
> 
> Available for ~$11 (US) on Amazon.
> 
> http://www.amazon.com/AMPRO-T71240-Energy-Ignition-Tester/dp/B00A8FO87S/ref=sr_1_4?ie=UTF8&qid=1453839488&sr=8-4&keywords=ignition+coil+tester
> 
> --mike
> 
>> On 1/26/2016 1:09 PM, David Forgie wrote:
>> I agree with Tom. In addition you can use a FLAPS coil tester to test the individual coil strength. I assume you are getting some missing at higher boosts. This is usually the sign of a weak coil.
>> The coil tester will allow you to find the culprit
>> 
>> Example coil tester: http://i.ebayimg.com/00/s/MTEwMFg4MzY=/z/B9wAAOSw~CRTqETU/$_57.JPG
>> 
>> One missing and hesitation diagnostic:
>> 
>> http://forums.quattroworld.com/s4s6/msgs/22611.phtml
>> 
>> Good luck
>> 
>> Dave F.
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> 
> 
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