2003 Kia Sedona won't start since the temp dropped to 20 degrees. I changed the battery, fuel pump, plugs and the IAC valve. We cannot find a fault on the hand held diagnostic and don't know what else to check...? PLEEZ HELP!

Have you checked the injector rail with a gauge to know for sure the injectors are not getting fuel ?
If the pump is running but not pumping fuel I would think it is a clogged filter or screen in the tank.

If this is a sudden occurrence and nothing suspicious happened prior, you most likely lost either gas or spark to the engine. You need to check for both.

Do you hear the fuel pump in the gas tank buzz on for a couple of seconds when you turn the ignition key to ON? Unless the fuel pump turns on and puts gas under high pressure at the fuel injectors, the engine cylinders won't get gas to start. Correct fuel pressure is crucial to know if you have a fuel pump (or fuel filter) problem. If the pressure is correct, it is probably not a fuel problem but a spark problem, although there are less common instances where a fuel injector circuit may malfunction.

The ignition system not producing spark at the spark plugs is the other common problem of no starts. Buy a cheap spark tester at a parts store, plug it into one of your spark plug wires, then crank the engine over and watch for a strong blue spark. You might need a helper to do this. If you see a consistent spark, the ignition system is probably good, although you should probably check more than just one plug wire-sometimes one bad ignition coil in a coil pack will cause no starting. Good luck.

Have it scanned for fault codes as an indicator of the problem. If the throttle valve is gummed up, cold temps can cause it to stick. But diagnose first!

the sending unit is a variable resistor(potientiometer ) on the fuel pump
its probly bad it requiers a couple confirmation tests prier to dropping your gas tank and changing the pump but I got my money on that sending unit 97% of the time new fuel pump will fix it you coul change just the sending unit but you still have to pay almost as much and its the same job smartest thing too do is change the whole thing

try starting it with about 10 percent gas pedal applied. If it starts this way most likely the Idle air control valve is the problem.

For this condition there is never a code. Always clean the throttle bore and install a new IAC valve then reset the PCM even if no codes exist in order reset all the sensors in order for them to relearn.

start of at the gas tank look under neath there are some black lines running towards the engine follow it to a small gold color that ataches to the line you are following that is the filter the pump is in the gas tank you need to drop the straps at the tank to bring it down

Drop the fuel tank and replace the fuel pump. Filter is attached to the fuel pump. Sounds like the fuel pump is failing.

This is typical. When cold starting/running, it takes more amps to run. It is using amps for higher idle to warm up engine, Altenator is spinning faster, and all sensors are being used at same time.
This is why mechanics say wait til normal operating temperature before any testing is done.
Once the engine hits normal temp, the computer readjust voltage amps, fuel pressure, air intake, timing and more.

i have seen this in isolated cases at KIA , there was no TSB but the info was at the KIA site for techs , i believe it had to do with what was called the RORV , (roll over valve) , if i recall the fix was to drop the tank and replace this valve , it was in isolated cases .

J5

Kia have somewhere announced technical fault and are well aware of it something to do with an 'evaporator and that fact that your coolant temp is being misread at 45 degrees or something'. This is a recent discovery and so you may need to contact Kia, your local dealership may proabably be unaware. Check out the forums type in Kia problems into google and look for your problem.