Disco 2 2004 disco. td5 power loss and misfire on start sometimes.

I have been trying to sort out this issue for a long time. At the beginning I thought it was caused by old MAF, I have disconnected MAF. After more than one month' driving, this problem didn't happen, then I changed a new MAF, unfortunately this problem comes back again in three days, it happens sometimes. I have cleaned oil at the red connector of ECU and changed the injector harness and the fuel regulator. It seems it has no enough fuel to kick off engine, afterwards it comes normal. I am not sure which one should be diagnosed next.

Look up my thread 'Daisy is fixed'. This fault has multiple potential causes but injector seals is the most likely culprit. Look up Discovery2.co.uk for an excellent write up on how to to do it.

You should find somebody near you with tester and scan the ECU rather than replace parts based on guesses, then if no fault codes logged it's more possible to be injector seals or failing pump... also did you fit genuine MAF and injector harness?, cos if they were aftermarket you might have replaced them in vain

Thank you for your advice. I want to replace the injector seals myself. Is there any risk? I noticed some one has difficulty to start engine.