Afternoon gents,
Had a cold snap and temps dropped to 15F and battery decided to die. Worked fine before the freeze. Tried jumping and mini started, drove it around ~20 minutes to try and charge it. Turned off mini and it wouldn't start afterwards. It turned over slowly and lights dimmed. Bought new battery and installed. Car cranks fine but won't start. Found error codes P0102, P0742. Replaced air filter and spark plugs(mini has 95k miles). After unplugging battery for 5 minutes, codes were cleared but still won't start. I have two key fobs, both give same results. Lights do not dim while starting, even tried jumping, car cranks faster but still won't start. Any suggestions?

*edit* It is a 6spd manual

 

https://www.obd-codes.com/p0102

that or alternator?

 

Just picked some cleaner up from Advanced Auto and tried it. No luck. How would the alternator prevent it from starting?

 

Not sure if the P0102 code is sufficient to keep the engine from starting. In some cases -- Mini I don't know -- the MAF can be disconnected from the wiring harness and the engine run to see if the behavior suspected of the MAF is still present.

Don't ignore that other code: P0742. Torque Converter Clutch Circuit Stuck On.

Read more: https://www.autocodes.com/p0742.html

Assuming the MAF or the clutch circuit stuck on are not keeping the engine from starting my WAG is the fuel pump is not working. Not familar with the Mini yet but in some cars one can hear the fuel pump run when the key is turned on and before starting the engine.

(BTW, when the fuel pump on both my Boxster quit and more recently on my 996 Turbo, both engines "cranked faster". They were cranking faster because they were not starting and the starter was running long enough to spin the engine at full starting RPMs. With everything working right the engine normally starts after just a rev or two until a cylinder gets to a full power stroke and when that one cylinder fires the engine is off and running.)

A "test" of the fuel pump could be to disconnect the pump from the car's electrical system and supply the pump 12V power to see if it runs. Now this assumes doing this is ok. With some cars it is. But maybe not all. You need to be sure it is ok with your car and its fuel pump before you proceed.

If the test is ok to perform and if the pump runs then a fuse, or a fuel pump relay is suspect.

But another suspect then is the crankshaft position sensor. if this isn't working right the engine controller won't know when to trigger a fuel injector pulse or a spark so neither are triggered. A poor man's check of the crankshaft position sensor is to note if the tach moves any when cranking. In some cars a lifeless tach during cranking is a sign of a bad crankshaft position sensor.