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My fuel pump assembly top was leaking fuel and another member was kind enough to send me his one which was not leaking and probably only a couple of years old. I bought the adapter wiring harness from the dealer and a new O-ring.
1) The wiring harness just connects to the existing one right? As in the picture?
Because I have a mixture of old and new parts I noticed the wiring harness (new adapter or old doesn't matter) flips 180 degrees on the new top hat connector. The live and ground are correct for each pump but the live/ground on the pins 1/2 of the connector now power the opposite fuel pump that it did before.
2) Does this matter? Or do I need to switch these wires from each pump around?
This diagram would lead me to believe it wouldn't matter which pump is acting as a primary/secondary?
My fuel pressure before doing this was 78psi idle and off boost, it dips down briefly to 75psi on boost and then straight back to 78-80psi.
After the wiring my idle fuel pressure is still 78psi but I haven't taken the car for a drive yet to check on boost.
If it’s a pre-2006 car the order of pump won’t matter - both run all of the time. Post 2006 car had two controllers that run one pump at idle/cruising and two under load.
Just make sure live is live and earth is earth when you connect the wiring all the way to the pumps. Don’t rely on colours - trace them. Both pumps are identical and so will be the wiring.
Before I chucked the whole fuelling system including the tank my pressure read 6 bar at idle and was dropping under WOT. What you see is an absolutely normal behaviour as the more fuel is being used by the engine, the higher is pressure drop. So long as it doesn’t drop below the level that’s needed to feed the injectors, you’ll be fine.
Thanks for that, yes 2005. I was a bit confused as the adapter harness is about 50cm long, seemed a bit excessive, I was almost wondering if it was supposed to replace the existing one altogether.
I will go for a boost tomorrow and make sure pressure is adequate still. As far as I can tell the wires are perfect in terms of live/earth. If one pump is backwards I would expect a fairly noticeable fuel pressure drop. Then just need to hope everything holds up when I fill the tank to the top, haven't done that for a while.
Sounds like you don't need the adapter cable. Like Alex said, make sure your hot and ground aren't mixed. I chose to swap two pins in my harness and avoid the extra wires and connections.
I'm not sure if the New Zealand spec car uses the 00-00 fuel pumps. If that is the part in the car, you will need the adapter cable. If the part number is missing, monitor fuel pressure at WOT with the adapter cable installed and uninstalled. The incorrect configuration will drop from from around 5.5 Bar to ~3.5 to 4 Bar. Correct configuration will be closer to the 5.5 Bar.
Sounds like you don't need the adapter cable. Like Alex said, make sure your hot and ground aren't mixed. I chose to swap two pins in my harness and avoid the extra wires and connections.
It looks like there are three wiring changes when switching from old to new. One pump wire is switched around, then the loom plug is switched 180 degrees, then the new adapter fixes both.
Originally Posted by bbirdwell
I'm not sure if the New Zealand spec car uses the 00-00 fuel pumps. If that is the part in the car, you will need the adapter cable. If the part number is missing, monitor fuel pressure at WOT with the adapter cable installed and uninstalled. The incorrect configuration will drop from from around 5.5 Bar to ~3.5 to 4 Bar. Correct configuration will be closer to the 5.5 Bar.
Let us know how it works out.
These cars are very hard to do WOT runs in town! So the lowest I got was 72psi for a split second when initially flooring it. It then went straight back up and was mostly around 74-75psi during hard acceleration. I checked it a few times. I presume I must have it around the correct way.
This is the old unit, ground/live, ground/live.
When plugged into the new unit one harness changes live/ground.
The old existing loom plug (and the new one for that matter) in the car is D shaped. The new housing changes the D orientation 180 degrees so that instead of the pump wires on the right of the previous two photos having their wiring backwards... it corrects this one and causes the pump on the left to have its wiring backwards instead.
For anyone interested this is how I did the fuel pressure. I bought a 36" 4AN teflon braided stainless hose off ebay- I would recommend an extra 4-10" to route it a bit better. It came with two 4AN to 1/8"NPT adapters. I already had a 4AN 1/8"NPT adapter, I used my existing one as it had a much greater sealing area than the 4AN line by itself. I then cut the head off a small wood screw. Big enough not to fit through the 4AN adapter central hole but small enough to just fit inside the stock fuel rail fitting to hold the schrader valve down. Good enough for a once per year pressure test.
Resurrecting this with a question - My 03 E55 had the tank and pumps done in 2016, and does not appear to have an adapter harness. It is a 2015 dated 00-00 pump.
More concerning is that the insulation has worn away on one of the hot wires, and appears to have been rubbing on the metal cover plate...
I haven't pulled the pump unit itself to look at the internal wiring, but before I do I wondered if someone could chime in and let me know if the dealer did this incorrectly. I have the invoice and there is only one mention of a wire harness but it's the adapter that goes on the other side, part # 211-440-05-07. I know how warranty work can go sometimes...See pics for how it's currently wired, also note the slightly burnt looking pin on that side with the harness removed.
Looks like the dealer left mine out too, 4 years ago and another owner, I'll just pay the $20 out of pocket and pop it in myself. Worth noting - this car makes a ton of power, but I've had issues with how smoothly it's been delivered and chasing why it seems to pull timing beyond what others are seeing. Well, I think I have my answer now. Worth checking if anyone finds this thread chasing similar issues! I even ran fuel pressure testing as the OP did, but like he said it's damn near impossible to do WOT runs, watching a gauge, anywhere but the middle of nowhere!
12-11-2018, 12:01 AM
