Mis-Fire/Bad Alternator

[army_man1014]

Hey guys,

I'm having this problem when I go WOT. I get around 5500 in full boost and the car backfires/hesitates on me. It happened a few times and i haven't gone back into full WOT.

I thought maybe it was a bad battery after doing some reading on here, however, I just got back from Auto Zone and they hooked it up to do a load test. The results came back as a bad alternator and bad starter. Failed Diodes is what appeared on the tool from auto zone

I took out my multi-meter this morning and was getting good ranges with the car running and off but once I cranked her over and turned on the AC (full blast), radio, head and fog light the voltage dropped down to 12.5 or so.

What do you guys think? Bad alternator, fuel related issue?

 

[fbody83]

If your volts are at 12.5 during idle then you're most likely dropping below 12.0 during WOT. This would cause voltage drop to your fuel pumps and you're most likely going lean in the higher RPM range hence the popping and hesitation. Do you have an AFR gauge? I'd recommend staying off the throttle until you get a new alternator.

 

[SS EATR]

Sounds like my exact problem from a few weeks ago, I replaced my alternator and battery and so far no more issues

 

[army_man1014]

I don't have an a/f gauge yet. Guess I should look into one. I will replace the alternator as well. Any recommendations on a replacement?

 

[troymach1one]

Had this problem last week, alot of misfire first pull, my alternator failed on my next pull.

 

[Alex27]

Had this problem last week, alot of misfire first pull, my alternator failed on my next pull.

my car was misfiring on sunday under normal driving then died, jumped started it and ran for about 8sec then misfired and died again. had to get it towed all because of an alternator. seems like alternators are a common problem on these cars, could it be because they are mounted closer to the ground and get wet during rainy days?:shrug:

 

[Ortiz99]

Funny this thread came up. Have a customer with the exact same problem. His is much worse than yours. 11.9 volts at idle, with a/c on its at 11.6, voltage drops to 11.0 at wot then fuel pressure goes down big time. Not something I'd recommend anyone doing over and over again to see if it goes away or not, but we found that out during initial road test. Replace your alternator and you should be good to go :beer: