Help... 05 won't start after battery swap

Battery died, so swapped out. Started right up, but ever since swap the truck was idling very low..so low that when I came to a stop, it was shaking a bit and felt like it was gonna die. Drove for one full day keeping the AC on (to up the idle a little), assuming that the computer simply had not reset the idle to correct speed yet after having battery off. Well, this morning, started the truck, backed out of my spot (still idling very low), and when I shifted (auto) into D from R, the truck died. Would not restart, and still will not start. Turns over great with new battery, but does not offer to hit like starting at all. Any ideas? Any help appreciated.

 

Clean the throttle body, I bet it's really dirty.

 

Yup this, dirty n sticky.

 

Probably does need cleaned, but strange for throttle body to cause an instant 'no start' situation. Truck has been running good...no issues until battery died...even after the swap. Only issue was the low idle, but ran fine. I was wondering if the engine dying from the slow idle could have sent an error message to the ecm / computer?

 

I mean it may be 2 separate issues but I'd definitely start by cleaning the throttle body, when you disconnect the battery the PCM forgets it's learned values and with a dirty throttle body that will cause a low idle and stalling.

 

Pro tip. For next time, or try again.

Next time you connect the battery, instead of starting it, simply turn on the key for 10 seconds. This lets the throttle sweep and learn its resting position. 90% of the time it prevents the low idle even on gunked throttle plates.

I'd clean this throttle, disconnect the battery and try again. Again, key on 10 seconds, then start it.

 

Even though it's a new battery, can you check it to make sure it is operating correctly? I had an experience of a new battery from Autozone, worked for like a week and then stopped. Took it back for a test and it was under voltage.

Also: https://www.youtube.com/watch?v=Ulp72690tmQ

 

I did exactly what you suggested... it started! Throttle body was pretty dirty. After cleaning, turning on key for 15secs, and re-starting. It started but died, however, I was able to get it re-started (with some added accel pedal push), and it now is idling around 1500rpms. Seems high, but at least it's running. Thanks for the responses.

 

Let it warm up to operating temp and it should come down, idle learn doesn't begin until coolant temp reaches 174F. If it doesn't you may have to do another battery disconnect to reset it but it should.

 

Throttle does not do a sweep at all when keyd on.

Now, when reconnecting the battery, turning the key to ON without the motor running then smooth pressing the throttle to the floor and back to idle 2 or 3 times, this will let the computer learn the end stops to the throttle plate.

 

Fixes a problem/makes truck run better. Virtually no physical exertion and costs nothing. I love it.

 

Had this exact same issue after having my battery disconnected last week. Super low idle and weak start. I unplugged my MAF sensor and checked it. It looked clean, so I put it back in. After that it started and ran fine. So check the MAF sensor. It may just need to be unplugged and plugged back in. That's essentially what made mine work.

 

Bare metal connections become oxidized over time, even when they are connected. You won't notice until you clean a connection and compare it to another. Removing/replacement of a plugin part may scrape enough oxidation off the connection to make it work. Best to clean that connection if that's the case. Clean connections with a pencil eraser or other non destructive cleaning.
Doesn't take much to cripple low voltage, low power systems. Also costs nothing to try.