So the problem came back after changing spark plugs and coils about a day later.

Final resort was checking the pump and fpr.

Replaced the Walboro with an AEM 320LPH and installed SOS wiring kit.

Problem seems to be solved now.

The 255 pump looks to be working fine. The fuel filter sock was very dirty though. New sock installed along with the new pump. So far so good. My best guess is stock wiring was not able to handle heat/load and would cause all these problems. SOS should include the wiring kit with their super chargers. Don't see how anyone can remain on the stock wiring, and everyone on the forum seems to recommend upgrading the wires to avoid these issues.

Let's see how it goes. Hopefully this is finally over with.

 

I actually never had an issue with the stock wiring on my Ap1's and the AEM320. Years later on my second S I did end up doing the SOS rewire at one point as a preventative, and it gave me a ton of trouble so I was sorry I ever did it. After half a dozen times of being left stranded and trying to figure out what was going on, I ended up bypassing some of this rewiring and just running direct wiring to the pump, bypassing the re pinning plug SOS has you do, which was causing voltage loss/connection issues. My connections all looked good so it was confusing, but I had to do something to eliminate the possibility/variable and that was the problem. So, to me I'm a bit on the fence as to whether or not to recommend the SOS rewiring. At some point, say when running 600WHP+ the whole fuel system has to be reworked anyway, but not at 9psi with supercharger. I lean to if it isn't broken don't fix it mentality, just from my experience, until its proven absolutely needed. Again, the less shit you have to modify/depart from factory, the more reliable in my book. Hopefully your issues is resolved and you don't have a problem with the rewire. If the car suddenly wont fire up one day, go the pump wiring and start testing you have voltage there.

 

We found no issues with the old pump and Fpr. Has to be the wiring because everything else has been checked. Ever since the whole SC install, all my problems have been pump related. Aside from the wear and tear on old stock parts not related to the SC. Let's see how it goes.

I'm no longer running lean as well. This stupid code had me checking a whole bunch of other stuff when it was the pump this whole time.

 

SOS wiring kit is great and I am glad I installed that before boosting. AEM 340 LPH pump here. Working well but I feel like I should get a genuine Walbro just in case it fails on me.

 

when was the O2 sensor changed, i would swap it out to rule out a bad sensor if possible

 

I changed coil packs, O2 sensor, installed new pump and SOS wiring kit. Car running great so far. Need to retune though I'm getting terrible fuel milage. Guessing I am running a bit rich right now.

 

Which coil packs do you run? I ask because the famous Denso 673-2301 coils from Rockauto and Amazon failed on me after just a short while of boosted driving. 1 failed completely. The other 3 are still running but then I bought a replacement coil of the same type from Amazon and it failed on the first WOT pull!

Feel like I should go for genuine AP2 coils from Majestic Honda to avoid this coil pack issue ever again.

Yeah it sounds like you're running quite rich.

 

I'm running the K20 coils as recommended by Jeff Evans in one of his videos. Honda # 30520-RRA-007. These are listed on Hondapartsnow as 04-05 S2000 coils if I remember correctly. Unfortunately, I found out after I purchased them that you can get them for half the price directly from Denso (part number 673-2301). So I paid a premium because the plastic bag they came in has a Honda sticker

Edit: So we are running the same coils. Not sure why yours are failing. Everyone seems to recommended these exact coils.

Been a few weeks and I have no issues. Still need to retune, the terrible gas milage is killing me. I don't know if this is related to the new coils, but tuner says its most likely the new pump as it flows more than the old one. I'm running 100KMs less per tank than I used to! Waiting on some pipes and hoses to arrive to do the CAI mod and will be installing a smaller pulley and a larger heat exchanger.

 

But alas, we don't run the exact same coils since the 673-2301 I bought from Amazon are hit or miss The 2 that failed are probably Chinese knock offs. You made the right choice buying directly from a Honda dealer as they will only sell genuine Denso, no questions asked. You should have bought from Majestic Honda though since they're $35 less per coil! I paid $66 per coil. Bought 2 for now just to test and ensure nothing else is wrong. A few miles/months later I'll get the other two AP2/K20 '04-05 coils.

If you bought a new pump that is larger than your old one then your tuner needs to recalibrate the fuel map as it will flow more fuel to your injectors causing your very rich, fuel heavy condition.

 

I'm not in the US

Literally any part I need for the car no matter how big or small has to be ordered and shipped internationally. I ordered from eBay from a good seller.

Parts I mentioned in my last post have all arrived. Will be installing and retuning tomorrow