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[El Beefo]

Just picked up an p75 w/ a blown Q31 trans. Checked my parts P28 and pulled Q31 to fix said p75. Heres the problem The transistor on the P75 reads D1780 and the replacement I pulled from the p28 reads D1779. Can I still swap it? Only found one thread online bout this. Anyone else have some input.

http://forum.pgmfi.org/viewtopic.php?f=4&t=660

[SgtB]

The collector to base voltage is 10v less on the 1779, but it's still 60 which I doubt is too little for a 12v ecu.
I think it will be fine as every other spec is the same, or fairly close. They're both high hfe npn.

Datasheets:
http://mycomputerninja.com/~jon/www.pgmfi.org/twiki/pub/Library/D1780/2SD1780.pdf
http://pdf1.alldatasheet.com/datasheet-pdf/view/94898/NEC/2SD1779.html

[El Beefo]

Bingo! thats exactly the info I was looking for. Honda ECUs arent to anal so I was thinking it should work. Ive also seen other boards w/  D1779 at Q 31. 

[theidealone]

Q31 controls the Evap Purge, right? Why fix it?

[92CXyD]

I replace them because I do not know what all the possible future uses of the ecus after me.  ;D

[snm95ls]

Q31 controls the Evap Purge, right? Why fix it?

Cheap two stage boost control.

 

[SgtB]

You never know how a blown transistor can react either. It can dump line voltage back into the output of the cpu. Bad.

[HiProfile]

Cheap two stage boost control.

My plan for purge is to operate a solenoid valve that opens a quick spool valve... :yes: But there are many possibilities.