1997 VW 1.4 Polo Classic. Car won't start after it was parked in the sun. Now, it starts early in the morning when it is cold (±15 ºC). It would go as per normal but won't start again after ± 1 hour of standing. The oil pressure lamp flashes when this is the case - it won't start and lamp goes on when key is released. Could it be the oil pressure sensor or the ''knock'' sensor. Temperature sensor was replaced and coil.

SOURCE: 1992 VW Polo 1.3L Coupe: warning light mystery

Polo Coupe 1043,1992, Will not start, can be bumped started, sometimes!!, theres a strange clicking noise from under the air box, when the ignition is on and sometimes the oil pressure light comes on when the car gets upto temperature, then I lose all power and then the engine cuts out. I've recently changed the dizzy cap, rotor arm and battery, all the leads are new ish along with the spark plugs. The previous owner has changed the head and done all that, leaving much of the engine loom unlagged and bare. Could this cause a problem on some of the electrical systems?

SOURCE: vw polo car wont start

try disconecting the coolant temp sensor and then try, it may be faulty, also check the hall sender unit in the distributor, if it has one, the centre pin should be the signal wire if no pulse is present the sensor is faulty

SOURCE: ENGINE CUTTING OUT WHEN COLD

idle air control valve is going bad

SOURCE: VW Polo Classic 1997 IDLE Problems

Hello, VW polos 1.0, 1.4. 1.6, suffer from carbon bulid up in the throttle bodys causing bad idling, esp the Bosch Mono-Motronic (Throttle Body Injection systems), a good clean with carb cleaner should repair the problem, also engine temp sensor replacement and idle speed control valve replacement can help idle problems.

SOURCE: What is the firing order of VW POLO 1.6 classic

!,3,4.2..Standard for most 4 cylinder vehicles