Car running way rich after alternator upgrade

[bcmaxx]

Upgraded my tired old alternator, max output was 11.8 volts.. installed an 06 impreza alternator, output 14.18 volts now my car is running way rich especially on boost?? weird??

[cj91legss]

That means you should just add more boost.

JK... or am i?

Seriously tho, the alternator actually has a lot to do with the electrical system. How much power it puts out is critical. Your old alternator was tired for sure....

[smagg26]

DID THAT JUST BOLT ON? I'VE BEEN LOOKING TO UPGRADE MINE, WOULD LIKE SOMETHING THAT HAS A HIGHER OUTPUT THAN 13.4

[bcmaxx]

DID THAT JUST BOLT ON? I'VE BEEN LOOKING TO UPGRADE MINE, WOULD LIKE SOMETHING THAT HAS A HIGHER OUTPUT THAN 13.4

more boost is in order lol, im only testing at 8psi, new shortblock just breaking in!

and the alternator was a bolt in yes, but... I needed the newer pigtail off the newer car, and you have to delete one wire old leggy 3 wire, newer alternator was 2 wire

[smagg26]

COOL. WHICH WIRE WAS IT IF YOU DON'T MINE ME ASKING? OR IS IT JUST COLOR MATCHING?

[bcmaxx]

COOL. WHICH WIRE WAS IT IF YOU DON'T MINE ME ASKING? OR IS IT JUST COLOR MATCHING?

I deleted the yellow wire with no ill affect.

[smagg26]

OK THANK YOU FOR THE INFO

NEED TO GET ME A 110 AMP TO COMPENSATE FOR THE OVER DRIVE PULLEY

[robertpaige]

So all you did was just clip the yellow wire out? Damn!

[bcmaxx]

So all you did was just clip the yellow wire out? Damn!

thats it!

[Legacy777]

The difference between the old and newer style alternators is the third wire is a turn on lead. The newer alternators turn on automatically once they get above a few rpms. Make sure to tape up that third wire because it will have 12v going to it.


Regarding your running rich, I would recommend resetting your ECU. The ECU has a table that adjusts injector pulse based on voltage. If you had consistently run with lower voltage the fuel learn trims probably added more fuel to bring it back into the region it should be. Now that you have higher voltage your fuel trims are off. Resetting the ECU will get rid of those fuel trims.