Does that method work for an 89 3-wire alternator or is it for a 94 4-wireThis may sound nuts...........lol
Next time it starts acting up, pull both alternater fuses....and see if it suddenly works perfect. dont drive to far.....no alt.
I had the same issue.....changed all kinda parts to no avail.
My alt showed it was charging just fine, BUT it turns out the field was going bad, just alittle, and it was causing my ecu to have fits.
Stalling.....sputtering....back fires, as if ignition was failing. I bashed my head on it for days.
I pulled my alt furse, drove like a charm, so new alt, fuses back in.....perfect.
Alt will show charging fine on a tester too.....thats why you must pull fuses to see if prob goes away