Hoping for some advice. I'm having a couple of issues and don't know if they are related.

1) A month or so ago, this started: If I left the truck parked for a couple of days the battery would be completely dead. Dead as in no interior lights, no dash lights..nothing. Could charge it and it would do fine as long as I drove it daily. The battery was 5 years old, so I assumed that was the problem. I replaced it, but still have the same issue.

2) I drove it yesterday, it started and ran great. Today, after changing the transmission filter and fluid, I went to start the truck and had a dead battery again. Completely drained. Hooked up the charger and and a jump box to start it.

3) Won't start. It cranks, but won't fire.
What I've checked so far:
- Fuel pump comes on and I have fuel at the fuel rail valve.
- I get spark at a plug, but it's a yellowish orangish spark

When cranking, it doesn't seem right to me. Almost like it's out of time or something like that. Not a smooth consistent crank / spin.

Any thoughts or suggestions would be appreciated.

 

Update: I charged the battery more until it was fully charged. Disconnected the battery cables for a few minutes. Tried it, and it cranked and started perfectly.

 

Of course.

The PCM's on these trucks are really voltage sensitive. May be enough to crank the motor, but, the PCM still gets confused.

We havin' fun yet?

 

:-) Well....I wouldn't call it fun, but I'm having something.

I am also trying to figure out a rough idle / trying to die thing after it sits idling for a few minutes. I didn't have any codes / check engine light, but I pulled the throttle position sensor out while it was running, and it didn't change how it idled. I was surprised. Thought it wouldn't run without it. Plugged it back in, turned the truck off and now when I restarted it I have a check engine light and a code P0123 / TPS something or another.

I'm wondering if I might not have a PCM going out? I have the voltage drain happening. The cruise control not setting. The TPS sensor thing. Am I nuts or is that a possibility?

 

It's certainly possible...

If you start the truck cold, will it idle good for a couple minutes, and then start stumbling?

 

Yes. That's a good description of what it does.

 

Unplug the front O2 sensor. See if it runs any better.

 

Thank you. I'll give that a try when I get back to working on it next. If it does run better with it unplugged is that an indication that the sensor is bad? Or is it an indication of some other problem?

 

I think that's an indication your cat is clogged

 

Indication the sensor is bad. If it still runs bad, remove the sensor, if it runs better, THAT means the cat is clogged.