integra stalls under load

[chemo]

94 Acura Integra B18b1/gsr head
The battery light came on and diagnosed the alternator being the issue. Replaced the alternator and when adding electrical loads makes the idle drop to the point of nearly stalling. Idles around 1K RPM, turning headlights on ~900, high beams ~800, turning on the A/C -400 rpm. Raising the RPM to 1200 then letting off stalls the engine. All of this is done in neutral. Engine idling, battery voltage is 14.3 while adding loads reduces the voltage at the battery. raising the RPM (2k) with all loads battery voltage is 12.6. Those battery voltage numbers are off the top of my head but will give accurate numbers in 20 hours.
Thanks in advance

Topic

[dan]

did you say 12.6V with or without engine running? that is what it should be like static… i suggest getting the alternator tested if that is the case, perhaps its putting out the correct Voltage, but not holding under load, i would also check all electrical connections, too the alternator and too the battery… and just for kicks check battery voltage static, a bad battery can cause all sorts of wonkey issues, static battery voltage should be somewhere around 12.6V and if you want too, do a starting test and when starting the car the voltage should not drop below 9.6 Volts… but it sounds a little bit like a alternator issue but diagnose first.

[chemo]

Battery voltage is 12.5
battery voltage while idling 14.25v (idle 1200RPM)
headlights + highbeams 14.1 (idle @ 1100RPM)
a/c on max blower battery 12.43v (idle ~200-300RPM)
rev to 2k RPMs battery voltage 13.9-14.1

When letting off from 2k rpm to idle with all loads mentioned above on engine almost stalls.

[college man]

If you used a aftermarket alternator that may be the problem.
see if this link will help. Have your battery load tested.

http://www.ericthecarguy.com/faq/solving-automotive-electrical-problems

[Ingvar]

LOOSE BELT.
LOOSE BELT.
LOOSE BELT.

Or

WARN OUT BELT/OIL ON DIRT
WARN OUT BELT/OIL ON DIRT
WARN OUT BELT/OIL ON DIRT

Sorry I sort of played with caps, but it’s like in your face most common cause.
Make sure battery terminals are cleaned.
I can tell from my Torque app that on my 09 Ridgeline, battery voltage indeed drops down when “load” is added. It’s pretty normal. ECM always redirects current o crucial systems first, that being ignition priority #1.

[Andrew]

Isn’t the IAC valve meant to compensate for electrical loads?

[Bill]

Sounds to me that the idle air control valve is not reacting to engine load or the throttle body is dirty. I suggest that you give both a good cleaning with throttle body cleaner and let us know the results.

[jdub1022]

I suggest a little regular maintenance first. clean the throttle body and IAC. have you done a tune up lately? if not, do one! also load test the battery. putting too much stress on the alternator without much battery power to back it up can cause stalling or near stalling

[chemo]

Battery terminals are clean and tight, alternator belt has no fraying or contamination also it’s not loose or too tight. Throttle body is clean, tune up was done recently. I haven’t done a physical inspection on the inside of the IAC but It is getting power. I unplugged it while idling (no loads) the engine and had no effect on the idle. I’m not sure on checking the IAC if its being commanded on without an oscilloscope. I do have a DVOM

[Author]

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