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Discussion Starter · #1 · (Edited)
Good evening gentleman, 04' 760li w 116k. Since my recent 5months ownership I've replaced with genuine as follows. (Myself a bmw tech)
  • Both sides pcv and respective "F" tubes.
  • 12 plugs (ngk R) 4 prong.
  • resealed upper plenum gaskets
  • cleaned both throttle body's without moving plates
  • 2 Bosch downstream 02's
  • 12 Bosch coils
  • Cam sensors.
  • both fuel tank breathers and respective plastic lines into the TBs.
  • Fresh coded Battery (was the 1st thing I did upon receiving car)
  • I've also reset adaptations after o2s a few times. Seems to be smoother for a drive cycle or two.
So I have the dreaded kind of "tired" and weak-ish/long-ish crank upon any startup. I have in hand a kit to rebuild the HPFP, all diaphragms and all O-rings. I'm going to assume this and me not having replaced any of the fuel filter components is most likely the culprit. (New main fuel filter OTW (the big one) I can remember seeing both values around 3mpa on my live data at idle. Both setpoint and actual values i belive.. Does anyone have any sources for known good hardware for the actual pump body itself? Looks like previous owner has changed one to a different type, one of the fasteners is a stud eith a nut! And the other ones that are usually a penta-bit are now all torx!....so someone's been here before. Ugh. see attached pic. Of said situation. So ideally I'd like to source new hardware bolts. I've seen the torque spec to be 69in lbs for the pump "hat" am I correct in saying this? Tmm a.m. I'm going to pull the bottom "T" tubes off the bottom underneath the fuel tank breather units, ill see if any fuel spills out. I'm pretty sure when I replaced the breathers I had a lil spill of raw fuel come out. So I'm sure starting here at the HPFPs are a good start point.
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Discussion Starter · #2 ·
Also, for what it's worth, I've checked all voltages and all are fine in both batt voltage and alternator running voltage. Also if this helps any the car will come t a stop, idles down fine, stays smooth at the 450-500 mark and stays nice and smooth, doesn't surge or stumble. However when I give throttle and ask for power and start to take off again, the initial feeling Is almost like a dead MAF would be, very "laggy" and it hesitates badly and pow! It hits hard and takes off. There's no nice in between. I come from a M73 background. This being my 1st N73. I'm hoping this is bc the manifold is soaked with extra fuel loading up bc the diaphragms are leaking. Causing an incorrect fuel ratio and making it bog down. Once opened up and the air mixture catches up with a the extra fuel then maybe that's why it's still drivable at throttle. It does hesitate around 2500- onward.
 

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Hmm. I had misfire two years ago 222,000 miles both banks outside adaption limits. I bought 12 Delphi coils and 12 NGK Iridium plugs (single point - I have good experience of them on M62 running LPG) and I even got a set of Penta bits in readiness. But after coils and plugs and a Terraclean, I found it was good. 116,000 sheesh you've gotta love these cars. Love or sell.
 

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Discussion Starter · #4 ·
Hmm. I had misfire two years ago 222,000 miles both banks outside adaption limits. I bought 12 Delphi coils and 12 NGK Iridium plugs (single point - I have good experience of them on M62 running LPG) and I even got a set of Penta bits in readiness. But after coils and plugs and a Terraclean, I found it was good. 116,000 sheesh you've gotta love these cars. Love or sell.
So you've made it to 222,000 miles on your N73? Have you ever had to walnut blast to clean carbon ?
 

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So you've made it to 222,000 miles on your N73? Have you ever had to walnut blast to clean carbon ?
Nope, and I've run it on super market fuel for years. It is on it's nth autobox fluid and widgets. Rear left shock went and non-OEM replacement aged quickly meaning damping and so movement is different at back over bumps. Ride is still plush. And engine pulls past most modern cars. Only had the one Terraclean at 222,000 - no walnuts involved. It leaked a lot of 5W-30 but is better on 5W-40 with Liqui Moly and better still on 10W40 with Lucas, but it really need the valve stem seals doing. Electrics are its weak spot. Air quality sensor errors. Door CA sensors. Rear CA sensor errors. Multiple failures on the MOST circuit. Glovebox changer, SAT NAV, DVD changer and Bluetooth TCU so beyond economic repair, we listen to Bose Mini Speaker and I prioritised my e61 M5 and e30
 

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Discussion Starter · #9 ·
Nope, and I've run it on super market fuel for years. It is on it's nth autobox fluid and widgets. Rear left shock went and non-OEM replacement aged quickly meaning damping and so movement is different at back over bumps. Ride is still plush. And engine pulls past most modern cars. Only had the one Terraclean at 222,000 - no walnuts involved. It leaked a lot of 5W-30 but is better on 5W-40 with Liqui Moly and better still on 10W40 with Lucas, but it really need the valve stem seals doing. Electrics are its weak spot. Air quality sensor errors. Door CA sensors. Rear CA sensor errors. Multiple failures on the MOST circuit. Glovebox changer, SAT NAV, DVD changer and Bluetooth TCU so beyond economic repair, we listen to Bose Mini Speaker and I prioritised my e61 M5 and e30
Wow! That's amazing, seems
 
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