:::RHMT::: Real Home Made Turbo

General Category => Engine Management => Topic started by: El Beefo on August 22, 2010, 06:13:00 PM

Title: Q31 Repairs
Post by: El Beefo on August 22, 2010, 06:13:00 PM
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 (http://forum.pgmfi.org/viewtopic.php?f=4&t=660)
Title: Re: Q31 Repairs
Post by: SgtB on August 22, 2010, 06:42:08 PM
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://mycomputerninja.com/~jon/www.pgmfi.org/twiki/pub/Library/D1780/2SD1780.pdf)
http://pdf1.alldatasheet.com/datasheet-pdf/view/94898/NEC/2SD1779.html (http://pdf1.alldatasheet.com/datasheet-pdf/view/94898/NEC/2SD1779.html)
Title: Re: Q31 Repairs
Post by: El Beefo on August 22, 2010, 07:00:26 PM
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.  ;)
Title: Re: Q31 Repairs
Post by: theidealone on August 26, 2010, 12:08:58 PM
Q31 controls the Evap Purge, right???? Why fix it?
Title: Re: Q31 Repairs
Post by: 92CXyD on August 26, 2010, 01:14:18 PM
I replace them because I do not know what all the possible future uses of the ecus after me.  ;D
Title: Re: Q31 Repairs
Post by: snm95ls on August 26, 2010, 04:28:37 PM
Q31 controls the Evap Purge, right???? Why fix it?

Cheap two stage boost control.

 :P
Title: Re: Q31 Repairs
Post by: SgtB on August 26, 2010, 05:24:22 PM
You never know how a blown transistor can react either. It can dump line voltage back into the output of the cpu. Bad.
Title: Re: Q31 Repairs
Post by: HiProfile on September 08, 2010, 09:28:57 AM
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.