skyline HR30 Coupe.

[Chen]

Hi Guys. Sorry for bad English.
May i`m ask some question?
i`m have a Nissan Skyline 1982 year.

i`m buy new turbo and dizzy for it. i`m start the engine. But, after 20-30 minutes working engine will stop. No spark. i`m check ignition system and found broken(burned out??) power transistor on ignition coli. i`m replace it. His burn again. i`m replace coil (low resistance from honda). transistor burns again. why?
ECU use a fixed dwell time.
Can i`m use a VB927 from ST as ignition coil driver?
vb927 datasheet. http://www.datasheetcatalog.com/datashe ... B927.shtml

[sry_not4sale]

Now THAT is a real car

[jharvey]

Sounds like you have a snubber problem, but it's hard to say with such a brief description. If it's an inductive spike problem, you'll blow this driver chip as well. Check out these wikipedia articles.

http://en.wikipedia.org/wiki/Snubber
http://en.wikipedia.org/wiki/Transient_ ... sion_diode
http://en.wikipedia.org/wiki/Flyback_diode

One way to do it with out the extra snubber component is to use a PIP3104. It has over-voltage protection that bias's the input when you try to do more than 60V from source to drain. This will keep the voltage spikes down to 60V.

[Chen]

Thank you very much. I have read and try to resolve this problem.

[Fred]

Jared, you can't use those FETs for ignition, at least, you shouldn't. The flyback spikes are much more than 60V and it will do bad things to your spark and/or kill the drivers.

I don't know about vb927, but vb921 has VERY limited capability to drive anything much. They burn out if you sneeze near them. Get some OEM ignitiors with balls and try those.

[Chen]

last time i`m use a BU941ZPF. It`s have built in protection from othervoltage.

but transistor will died again. hmm...
maybe ecu uses some feedback for dwell time? it`s a jdm car and i`m don`t have any documentation for it.

[jharvey]

I agree with Fred about the use of external drivers. Use your drivers to drive an external OEM driver. I beleive this mazda is Freds.

http://i50.photobucket.com/albums/f323/ ... 0_4471.jpg

That link came from this thread.

http://www.diyefi.org/forum/viewtopic.php?f=3&t=16 (DSL beware)

Notice the plate attached to the firewall.

[Chen]

i`m swap ignition coil and problem will gone. maybe short in primary coil?

[Fred]

Yeah, that's entirely possible. Glad you got it fixed! :-)

[Chen]

after i`m swap coil and wires, problem is gone. thank you!