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Discussion Starter #1
Is there any way to test our coil packs or confirm theyre going bad ? I posted earlier this week about cutting out at 20 psi and this seems to be one of the possible culprits. I pulled the plugs and they still look brand new (only 1,000 miles) and checked boost hoses...no holes there or broken clamps that I can see.
I just dont want to spend $ on coil packs if thats not the gremlin.
Thanks guys.
Jeff
 

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You could check the primary side, but there's a diode on the secondary that prevents measuring resistance. The secondary (high voltage) windings are the more likely culprit to break down over time.

Your best bet is to swap in a set of known good coils, if you have them available.
 

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Discussion Starter #3
Thanks LT, I dont have any to swap out but the car has 140K on it and im not sure if these are the originals or not....I just hate to spend the $ for possibly no improvement to the car and if it doesnt fix the problem im further down the creek.
 

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Discussion Starter #5
the plugs are still gapped to .032, they are brand new and the problem literally started in one day. Thursday the car ran perfect, in fact it still does except when at WOT and full boost, if you 3/4 throttle it...she runs fine.
 

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Discussion Starter #8
whats throwing me off is it was running fine one day, then acting up the next so it seems something went out quick.
Are these DLI's worth the money ? I have been looking them up but with the search gone I cant tell who uses them and who doesnt. Although I am only BPU now I know the single is coming before too long.
 

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The weather changes from day to day too, don't forget that. Colder weather could cause you to miss on the top end and run fine the next day. Try regapping the plugs and see if it helps.
 

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I though you just take the coils out and test them with an ohm meter to see if they are within spec???
 

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One thing I'd like to put my 2 cents into is the whole plug gap issue.

On the one hand, if you can run misfire-free dropping the gap down to .028 or so for a stock twin or small single car running ~20 psi you *do* save the cost of new coil packs.

On the other hand, I've never needed to run that small a gap on my car. Not when it made mid-450 rwhp on stock twins with 100 octane, not now that I make ~510 rwhp on 91 with a 61mm.

I've run the out of the box gap (.8mm, or .0315") on NGK3330s, 6097s and now R5671As.

So far, with ~91k on the original coil packs it is going strong.

As always, YMMV, but IMO having to go below .030 for a stock twin or small single car on moderate boost is a sign the coil packs and/or connectors may be degrading.
 
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