4 new HPFP's, rail still crashes, LPFP looks fine.


New Member
Apr 27, 2020
I've put in 4 remanufactured HPFP's from FCP Euro and rail pressure still crashes on every pull past ~13psi. What're other possible failure points that could cause this?

I've also noticed a weird issue where the car bogs AFR's at idle occasionally (Lowest I've seen is 12.9:1) then leans out to mid 15's. Also on a cold start, with about 1/4 throttle input it'll stumble occasionally sort of like a misfire, but I've caught the AFR's in the 12's from the corner of my eye while monitoring. I assume this is what causes the stumble.
-Note: this weird AFR thing started occurring recently, whereas the fueling issue has been a problem since switching to a ST setup. So I don't know if this is a separate issue, or the primary issue is worsening leading to this.

DOC race turbo kit, Precision 6266 DBB turbo, JB4 with an MHD BEF for an E30 mix, 4 port MAC solenoid, VRSF 7.5" stepped race intercooler, BMS CP with a Tial BOV. PR relocated ignition coils, NGK 97506, stage 2 LPFP and index 12 injectors

Doc Vu is in the early stages of tuning my car, but we can't move forward until this is resolved. I'm really hoping someone can help me out here!

Edit: I'm dumb as rocks and can't figure out how to upload these logs cleanly, so here's links to Datazap and I've attached the .csv's too
log 1
log 2


  • crash issue 2.csv
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  • crash issue.csv
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Mar 29, 2021
I don't see that you're running port injection? Why is your fuel enrichment reading 100?

Should be 0 if not using port injection. Post pictures of your jb4 settings. If you are using port injection fuel enrichment still shouldn't be 100.