DIYEFI.org Forum

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

Now THAT is a real car

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.

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

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.

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.

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.

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

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

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