Brakes or lights causes rich A/F

[pwhitersxs]

Issue:

When I put load on the electrical system such as head lights, heat, brakes, etc the A/f goes from 14.7 to 12.5.

The battery voltage dips big time from 13.7V when the car is first turned on to 13.5V then when I have load on the system it dips down to 13.1V, but will climb back up to 13.5V.

Battery is 1 month old,
Voltage when car is off = 12.5V
Voltage when car is on 2= 13.5V
Tested alternator load pulled 55A.

Reasons:

Grounding (doubtful)
Alternator
Battery
Some weird vac leak (doubtful)

Car:
Sr20det
Stock ignition
No speakers or anything
A few electrical gauges


I did just fix the car from electrical issues. Any other possibilities or helpful comments?

[godsmack]

the thing that comes to my mind right away is the alternator. how does the car run if you disconnect the battery. if it stutters then you're alternator is not giving enough juice.

[pwhitersxs]

Well around 2000rpm the alternator put out around 55A. I am going to try a Q45 alternator (110A) to up the amperage and if I still have the problem then I will reground the ecu grounds.

[pwhitersxs]

The 110A Q45 alternator is in and no it is not a direct drop in. Problem still exists although not as bad. Voltage stays around 13.8 to 13.7 with the lights on and around 13.9 to 14.0 without lights on. Any ideas!?

When sitting at a dead stop at idle and I press the brakes, the AFR dips from 14.7 to 12.5. Can anybody explain or give me ideas as to why?

[GSXRJJordan]

Your alternator is not the problem - 50A @ 2000rpm is beyond fine.

I don't see a problem at all, actually. Sounds like it's fine.

[pwhitersxs]

A/f should not dip that bad. Thanks for the reassurance though cause the car does run great. Before my electrical issues, the car would never dip like that or atleast I never noticed.

It's just weird because the afr will dip into the low 10's with the LIGHTS ON and I just noticed that with the LIGHTS OFF the car is still running rich, just not as bad.

I already fabbed up a bracket for the q45 alternator so atleast I have a good spare stock alternator.

Any more ideas?

[yukon]

is the sr20 closed loop like the 240sx during idle?

[pwhitersxs]

My car does not run with an 02 sensor. I have eliminated it and the car was tuned without it.

[yukon]

My car does not run with an 02 sensor. I have eliminated it and the car was tuned without it.


Is this an idle issue? The car has to idle up to maintain the idle when there is more electrical demand. maybe iacv can't supply enough air for some reason. it might just be normal though to be rich . your voltage seems low though.