OK, it didn't totally kill my truck. I have an 04' Screw 4x4 w/76,000 mi.
I have owned my truck for five weeks now. It's awesome. Here in central Kansas we had a few very cold days (0 degrees) and my truck would not start in the early morning. I just thought the cold weather had made the battery weak. If I jump started, shut if off, and then started by it's self it was OK. It seemed like it needed some voltage to pass through, and then it was fine for the day. Anyways, I put a battery tester on it Monday and the battery only showed 380CCA. The battery was rated for 650CCA. So, I bought a new battery plus oil and oil filter for oil change. I changed the oil, replaced the battery, started the truck and it died. Tried a few more times and then checked the manual. On page 236 I find out how to let the truck relearn its idle functions. After going step by step and driving thirty some miles, the truck still stalls every time I come to a stop. And I do mean EVERY TIME. UUGGGHH!!! Is this the computer still relearning, the IAC, or something else? I have tried searching the forums but I can't seem to find my problem. Any help is appreciated.

 

fordsinair,

You definately have something else going on. Your computer has learned everything it needs to at this point. It's been a while since I turned a wrench, but I am guessing you have something going wrong in the trucks idle system (EGR valve, TPS or dirty throtle body comes to mind). Don't flame me.....I don't claim to be a qualified vehicle tech.

Is the idle the only issue or is the truck running bad when you increase the RPM's? How about the exhaust......does it seem normal or smell like excess fuel?

Changing the battery is money in the bank, so you probably didn't waste your money there. I replace my batteries before they die and leave me looking for jumper cables. Also, as the temperature drops, so does the power output from your battery. There's a dirty little secret in the battery industry. You always want to know a batteries CCA when purchasing one. CCA is an amperage measurement taken at 0 degrees F. CA is an amperage measurement taken at 32 degrees F. As the temperature rises, so does the battery output. A battery rated at 650 CCA versus a battery rated at 650 CA is definately stronger and will perform better when the temperature drops.

Shawn

 

Thanks for the reply. The idle issue and the common throttle dead spot. The new batt. is rated at 650CCA at 0 degrees and 880CCA at 32 degrees. I do notice it starts faster than before. When the motor is cold it will idle perfectly. After it has warmed up it will stall when coming to a stop. I don't have a warranty and my mechanic friend doesn't have equipement new enough to talk to this truck. So I took to the local dealer today. Hopefully they can just reset the stupid thing and it will be back to normal.

 

One of your sensors is sending a bad signal to the computer. When the truck is cold, the computer runs in a closed loop mode, which means, the truck runs on preset values from the computer. Once it warms up, it goes to open loop, which gathers input from the sensor's. Possible your TPS is going bad. I would def have it checked for codes.
Rich

 

Let us know what the dealer finds on your truck. 96f150 nailed it with his comment on the truck going into open loop. I doubt that there is a simple reset that will magically fix the issue but it will probably be a simple fix none the less.

Shawn

 

Put a voltmeter across the battery terminals while idling if you can. You should see around 14.5 volts. When the truck is off, it should read around 12.6 to 12.8. If not you may have lost a diode and need the alternator replaced. Lower voltage can cause improper sensor input.
A bad diode even though it still produces somewhat of a charge, it can cause back feed and voltage spikes and dirty DC.
If a sensor was bad it should throw a CEL. Even if the truck is in learn mode it should not stall since the base computer maps should keep it running. Under learn mode it might run a little rougher or hesitate.

The only reason I am coming from this angle is because you had a battery issue which could have been a charge issue. Did you have it analyzed after you did a full charge?

 

i agree with the sensor theory..... i have seen this before.... a somehow unhooked temp sensor and it did exactly that. once the engine needed to use the sensor, it would run horrible at best. let us know what they find.

 

An unhooked temp sensor would throw a CEL. P0125 thru P0119 DTC.

 

Wow. It's been a while since I've been on here. Thanks for the replys and sorry about not posting the results.

The throttle body was the culprit. It didn't throw the idiot light cause it was partially working still. The dealer tried updating the computer a couple of times to no avail. Then they replaced the throttle body because those throttle bodies were know to be a problem. That fixed everything. But the dealer was surprised the "Wrench" light didn't come on.

 

a throttle body?...wow, I was going to say it was the IAT sensor...that was a big problem on all my 92-96 F-150's. damn thing would throw it closed loop and run great, then die when at operating temp.

 

Gentlemen,

I am a transplant from the aerostar forum. We have lots of trouble with the maf sensor near the air cleaner. Simple to test. Just unplug it. If the engine now runs good, you have nailed it. You will get a cel during the test but it is easy, clean and free. Always do the cheap stuff first.

Ken