My 4/4 (tuned Ecotec VVTi with MBE ECU) has been getting more and more reluctant to start over the last couple of thousand miles. Nothing too terrible, it runs fine once it's going, but it's worse when it's been sat for a while, sometimes taking a good lot of cranking to fire. .....
You're mentioning difficulty in starting. My experince with engine management systems is that in the cranking phase (before the engine reaches running/idle phase) only few sensors are relevant. This is the crankshaft, camshaft, voltage level and water temp (of course you need spark and fuelpressure). Anything else is most likely ignored until the engine runs. Cranking phase is when the engine has less than 300 rpm. Voltage level is important because injection time varies significantly with lower voltages, which obvioulsy the case during cranking and the ECU compensates that.
