It has 730hrs on it. It sounds more like it’s detonating. It sounds fine if you put it in neutral and rev it up.My 825i had a miss and a knock. Not sure how rpms affected it, as I bought it that way and didnt run it much. Mine ended up being a bad rod bearing. Hope yours is easier to find and fix. Look for shavings in your oil pan to be sure. How many hours are on the machine?
I’m getting plenty of volume from the fuel pump. I’m not sure about pressure. I’ve tried high octane fuel and no difference. I couldn’t see any place where the spark would be grounding out.If you suspect more of a detonation issue, perhaps try adding one of the octane boosters or complete fill with premium (93 octane fuel) to see if it subsides.
The miss could be spark related (or lack of). Check the integrity of the spark plug wires and boot very closely. It doesn't take but a pin hole in the insulation for the spark to jump through the wire versus plug... A number of people have experienced bad spark plug wires in the past.
What additional diagnostics have you done since posting?
Does the knock start showing up as the engine hits operating temp? When it starts to knock what would happen if you eased the choke out a little bit but not so far as to make it blubber? I have no idea about the miss when starting up except to ask if its different with a warm start vs a cold start?I’ve got a 625i that recently started missing when you first start it up. That goes away but it has engine knock at a certain rpm. It’s fine when your running full throttle. I’ve tried sea foam, changing spark plugs and fuel filter
I had to replace my ignition coils. Little as $24 apiece. Corrosion got to the + lead on the rearI’ve got a 625i that recently started missing when you first start it up. That goes away but it has engine knock at a certain rpm. It’s fine when your running full throttle. I’ve tried sea foam, changing spark plugs and fuel filter