1999 F250 SD 7.3L cold starting problem

One possible reason for this could be a faulty engine coolant temperature (ECT) sensor. The ECT sensor tells the engine control module (ECM) the temperature of the engine coolant, which is used to adjust the air/fuel mixture for starting. If the ECT sensor is faulty, it may be sending incorrect temperature readings to the ECM, causing the engine to not start in cold weather.

Another possibility could be a weak fuel pump check valve. When the fuel pump check valve fails, it can cause the fuel pressure to drop when the engine is turned off, which can cause hard starting in cold weather .

It's also possible that the battery is weak and not providing enough power to start the engine in cold weather. Cold temperatures can reduce the battery's cranking power, which can make it difficult to start the engine.

I would recommend taking your vehicle to a certified mechanic to diagnose the issue.

You have to have a good air flow through the condenser..make sure the condenser is clean and clear of debris, dirt, leaves, ect....make sure the fan or fan clutch is working properly?

this is most likely a fuel vapor issue.

fuel boils in the fuel rail causing a hard start after a 'hot soak'.

the fix is to replace the fuel pressure regulator and the pcm. good- day !!

Make sure your plug wires are not being affected (brittle, old,etc}. An engine oil heater works well in cold areas. Possible thickening of oil.

Your glow plug controller is out, or there is an interruption in its power source, etc. Diesels are coldblooded by nature, and most need glow plugs to heat them up before starting in cold weather. The controller supplies the power to the glow plugs, but if it goes bad, or its supply of power isn't there, it won't start in cold weather, and that wait to start light which is also controlled by it won't come on.

This engine 'loves' glow plugs! One goes and the others try to handle the amps. Change them and you will have no probs! Other than that, I feel this is about the best diesel truck made!

check your glow plug relay! located on the right side head

replace the idle air control valve, does it start if you step on gas pedal, and when it starts does it idle up and down and stall sometimes if so then replace that valve, good luck.

if wont turnover check small wire going to starter for short or ground out. my f250 7.3 was doing same i found small wire going to starter broken and pinched by frame. berrydalewolf

It is possible that some of the glow plugs might not be working. This will cause a hard start and smoking condition especially in cold weather.