Peugeot 206 2001 GTI

What's the code P0 what . Codes do not mean to replace parts . especially when circuit is involved . This means a wiring problem .

If half the engine isn't firing, it may need a new coil pack. Most v6 and v8 engines have a coil pack for each side of the engine. Try swapping them around to see if the other side works; then you'll know. If it's not a coil pack, it's because your car has variable cylinder management, and it has electronics issue.

Sounds like a faulty starter solenoid or bad starter.Take a hammer and tap on the center of the starter housing while someone else tries to start it.If it starts then its your starters bendix that is bad in the starter. Make sure your wheels are chocked.

is the service engine soon light on? sound like the vehicle has a lean condition. posibbly a vacuum leak.

FAULTY COOLANT TEMPERATURE SENSOR OR IDLE AIR CONTROL VALVE MALFUNCTION.BEST TO GET CAR CODE SCAN THAT WILL SAVE TIME MONEY AND GUESSING.

How is your charging system? Sounds to me like it's not charging your battery, so it runs until the battery cannot support the ignition load.

Regardless of age, battery discharging first needs to be addressed and fixed - bad battery or something in car (like a light) may be staying on when car is shut off.
Fuel pressure is too low - should be around 50psi and may be caused by an intermittent fuel pump or regulator problem.
The cause of the other problems is usually with the IAC or MAF sensors or the EGR valve - fouling at the EGR, IAC and/or throttle body is to be expected for a car this old.

i have been fixing peugeots for 12 years and never heard anything like that.
it is mrer then likley a faulty crank position sensor, coil pack or quite simply the fuel cut off switch needs resetting which should be located under the bonnet on the n/s (black unit with a red rubber top) just press the top and try starting the car..

if this helps let me know
cheers
big mike

change the mass air flow meter.

Remove one of the spark plugs and see if it is wet with gas.
Let me know.
Regards,