neit_jnf

iTrader: (17)

First my question, can the coils work fine when cool and fail when heat soaked?

When I start the car cold, I always drive a while mildly until up to temp then go wot and redline a few times. Its ok for a while but after a while it boosts with no power and misfires badly at about 5k rpm when in boost. Feels like the time I had a bad leading coil and only driving on trailing.

The leading coil is fairly new, bought from Malloy. It drives fine at low loads. I'm only guessing the coils are failing when heated up. If that's the case, what can cause my car to damage coils quickly? I use a Twin power. What do you think?

1QWIK7

iTrader: (33)

IIRC twin power reduces the life of spark plugs. I would check that first.

Second yes heat plays a huge part on electricals. Before I go crazy on the coils/wires/plugs, check your AIT. If your heatsoaking, all that heat is probably making the AIT readings go out of whack making the car run funny.

DaveW

Yes, coils can be affected adversly by heat. Their internal resistance increases with heat, and if they (or the plugs/wires, etc.) are marginal, that can cause misfiring under high load. I.e., anything in the ignition system that is weak can cause misfiring that is more prevalent while hot/under load.

wReX

iTrader: (6)

I've seen the crank sensor go out of spec once things heat up... exactly as you described, car would run great then after getting hot it would start breaking up bad and eventually end up stalling out and not starting until things cooled back down. Does your tach give funky readings sometimes?

neit_jnf

iTrader: (17)

plugs and wires are fresh along with the leading coil, trailing coils have 60k+ miles

I disconnected the Twin Power and did a test drive today and voila! Problem gone!

What ignition would you recommend that not a Twin Power? I've had 2 in about 30k miles

1QWIK7

iTrader: (33)

I had a feeling it was the tp. Its threads like these that made me not get one.

Liborek

Real question is what´s wrong? Is it Twin power failing from heat? I´m not fully familiar with how exactly TP works, if its just some sort of IGN booster or capacitive discharge system. Nevertheless be it former or later, for optimal performing, it would call for different coil setup, something with low primary resistance. Otherwise I can´t see much advantage. In inductive setup, coil is coil, once its saturated, no more energy can be put in, given that wiring can support voltage and current, it goes to charge time - so why stuck with stock coil?

1QWIK7

iTrader: (33)

It seems to me that a tp is kinda like steroids to the ignition system. You don't need it if your stock system is performing optimally. Given you are stock or slightly modified. People get it as extra insurance cause maybe they don't have enough confidence in their stock ignition that it should help it if necessary.

If you maintain proper plug/wire/coil change intervals, Imo there is no need for an ignition amplifier, cause that's all a tp is.

Liborek

Well, I´ve been searching all around the web how HKS DLI system works and concensus is, that it somehow increases dwell time or increases inductance/capacitance and hence, to some extend output.

Then again with good aftermarket ECU you can run any coil and there are very good high performing inductive style coils well suited for rotary application - short saturation times, designed to operate in high RPM two stroke engines.

OP just look over certain EFI forum, it will open your eyes