1.0l 3 cylinder 5 speed. Why won't it start with key when it's cold out?

Did you replace the key switch ?

sounds like a bad connection or bad starter, when it runs it will heat up starter. when its cold the metal or bad connection will expand and contract. check main all connections going to starter

YOUR COOLINF FAN RELAY IS STAYING OPEN.

• Relays carry high-amperage current controlled by a low-current switch
• When a faulty relay is not replaced, the circuit will either be non-functional or remain engaged. HERE'S A NEW ONE.

http://www.autozone.com/cooling-heating-and-climate-control/relay-radiator-cooling-fan-motor/valucraft-relay-radiator-cooling-fan-motor/buick/lacrosse/2010/6-cylinders-g-3-0l-di-dohc/966628_0_0 Find the sensor that turns on the fans unhook the plug check for 12 volts with key and a/c on full speed should have voltage get cheap voltage test lite at parts store remember to hook one end of the light to ground{BARE METAL} got power ? if so I would first change the sensor it tells the fans when they need to come You can check the fans by getting a piece of wire and running it to the fan plug from the positive terminal of the battery the fans should run watch fingers or long hair You can run a wire from the battery to the fans with a switch in the middle to turn them on when needed but that can be a real hassle unless you run the switch into the car and keep an eye on the temp gauge.

Hi Kevin it sounds to me like your solenoid that is attached to your starter motor needs replacing had this with a ford cortina mk 5

Get a meter and see if starter is getting 12 volts,if not,your inline fusible link is blown.

Intermittent electrical problems are the worst to diagnose.
One thing you have not replaced yet is the key switch.
I would run a wire to the starter solenoid terminal that has the wire from the key switch and have a meter ready for the next time it fails to crank.
If you have no voltage on that terminal it may be the key switch. You can also jumper that wire to battery power to see if it will crank by putting power directly to the starter solenoid.
I am assuming the security light is not on when the problem occurs.

i'me asumeing the batt is ok....turn on lights, do they dim when you try to start engine? if not .bad selonoid on new starter..was it rebuilt? it happens. Billy Starr

When you start the Lancer, does it actually turn over and start? Or does it sputter while you're pressing the start button?

This is what I would start with. First, I'd find your fuel regulator and follow the vacuum line that leads to the engine - then unplug that. Find some extra tubing or rag that you can replace that plug with to keep it sealed. Then, if you're car starts running, you'll know its just a bad regulator.

If that doesnt work, the second thing I'd try is pulling off the air-intake and spray some brake cleaner in there to see if it will start. If that works, then you have a fuel leak or clog somewhere thats preventing your fuel from reaching the sparkplugs.

Hope this helps-

The ignition key cylinder in a Buick unlocks the ignition and allows the Buick's engine to start. The cylinder contains a switch on the end of it (inside the cylinder) that sends an electric signal to the starter motor. When the ignition key cylinder fails, the Buick won't start. When this happens, you'll need a new ignition cylinder. Purchase replacement cylinders from Buick.
Difficulty: Moderately Easy
Things You'll Need:

• Ignition key
• Punch pin
• Cross-point screwdriver

1. 1 Remove the screws on the bottom of the steering column on your Buick. These screws hold the steering column cover on. You may need to tilt the steering wheel to its highest position to access these screws.
   
2. 2 Turn the ignition key to the "II" position in the ignition cylinder.
   
3. 3 Slide the punch pin into the access slot on the bottom of the ignition cylinder.
   
4. 4 Push the pin all the way into the access slot while you pull the ignition cylinder out of the steering column.
   
5. 5 Insert the new ignition cylinder into the steering column with the key in the "II" position on the cylinder.
   
6. 6 Push the cylinder into the column until it "clicks," indicating that it is locked into the column.
   
7. 7 Turn the ignition key to the "Off" position.
   

your starter solenoid is bad,remove starter and bring it to autozone for a free check.