I8ayellowcrayon

I bought a P28 from a friend, and found out that the tach is not working. After looking at the board, I found that a transistor (I think) is burnt. Its labeled as Q31, and is here:



I typed in the numbers that I found on the transistor into the Radio Shack webpage, with no luck. Does anyone know what part I need to repair this? Is this related to the tach not working?

Thanks!
Jason

I8ayellowcrayon

Anyone? Or does anyone have an idea where I can go to find out (since PGMFI is down).

Luserkid

Im 95% sure Q31 burns when you cross IAT and EVAP wire. Although it sucks and i believe it messes up your idle it shouldnt effect your tach. Tach signal is usually straight off the dist. not the ECU. Check your blue wire from your dist to your cluster. Out of curiosity, with another ecu? Could also be that pervious owner hooked up the tach and did run it straight from ECU. But bad tach usually equals bad ignitor.

I8ayellowcrayon

Sorry for the horribly late update, but yes the tach does work with the factory OBD2 B16 ECU.

jasony0630

hey!

my ecu is fried like that too....except everything works fine....no CEL's either.

I8ayellowcrayon

Weird.... Maybe I have a bent pin or something.... Strange.