Rough idle,bad battery?

After playing in the mud my truck will only start when jumped and it will idle fine for about 2-3 min and then idle rough and shut itself off there are no engine codes but the battery light is on the throttle body and mass air flow sensor looked clean but I put some throttle body cleaner through it but that didn’t do anything. Any ideas before I take it in to a shop. 2002 TRD off road 3.4L

 

Low system Voltage will cause it to do that.

Maybe just to much Mud in the alternator.

Time to break out the Meter

 

Did you check that your alternator belt is still on? Mud could have thrown the belt. Definitely not battery, it's related to your alternator.

 

Your alternator brushes may need to be replaced and not related to playing in the mud.

 

You definitely need to pull out your altenator, I would use crc electrical cleaner to clean it and any autozone can check if it works fine after that. It could be dirty brushes/commutator, or it could be its voltage regulator going bad. Rebuilds are cheap and fairly straightforward. Dont forget though, if the altenator has been going bad it could have been taxing youre battery, and if the altenator is bad youll need to see if it harmed the battery aswell, or you risk ruining a new or rebuilt alt. These alts are very high quality they have a class leading hairpin stator in them and is better than other manufacturers alts being denso brand.

 

Alternator is toast. I have ruined a couple of alternators from mud. It's not in a good place in the engine bay. I don't play in the mud anymore. At least not swimming pools worth.

 

This would be my guess as well. Been there, done that!

Sounds like the the alternator is not putting out any amps to charge your battery. When you jump it, the battery gets a little bit of juice which keeps it going for a short while but once that is gone the engine will stop running.

 

Thanks for the info guys there was dirt all over in the alternator so I bought a new one and replaced the battery anyway ants it’s as good as new

 

I'm having the same exact symptoms and I'm at 187k on the original alternator so I'm going to tackle that tomorrow (replaced the 4 year old battery today). Just curious, which alternator did you end up going with?

 

I have one for sale if you want an OEM one

 

Hey thanks for the offer. I got it all taken care of. Sorry I didn't see this sooner.