Lost boost with no codes shown, but runs fine a day later?

[BeastMode335i]

Well Friday night my buddy was down in Mexico with some other friends and they were enjoying some spirited runs.. My buddy has an 09' 335i, Stock Turbos, FBO, MHD Stage 2+, and a few gallons of E85.. Monitoring his fuel trims, everything looked fine but the LPFP did hit 55 on one pull, and after doing a few (2-3 perhaps) back to back runs, his car lost boost.. It showed no SES, CEL, errors, anything, just no boost on full throttle.. So he pulled up to my place and I checked it out, all connections were tight (CP, FMIC, BOV, vacuum lines, etc) and everything seemed fine, but still it would not build boost.. So he drove home as it was around 2am and I said let's check it out tomorrow.. Well sure enough, about 8 hours later he calls me and tells me he just woke up and took it for a little ride to get breakfast, and everything is back to normal and he's hittin target boost no problem..

So, the night before it literally had zero boost, but after sitting for about 8 hours, it's back to normal and running fine.. Now with no codes or anything to help diagnose, is this some sort of quirky glitch perhaps related to a tune?? Another friend mentioned perhaps a stuck BOV maybe, which I guess could have happened, but if a BOV was stuck open wouldn't it still at least build a little boost..?? He literally was at 0 psi on WOT, however vacuum was fine so I don't think it's a vac issue..

It ran great all day today as well, so not sure what that was all about but he's not on the forums so I told him I'd come and ask for him so he could have some ideas of what caused that..

Thanks in advance..!

 

[doublespaces]

Odd, maybe a stuck wastegate? But that seems unlikely.

 

[BeastMode335i]

Odd, maybe a stuck wastegate? But that seems unlikely.

That was the first thing I said too, but then I thought if the wastegate was stuck wouldn't it show on the vacuum side of things..? And if it got stuck I also imagined it would have had to somehow get unstuck lol, which I couldn't figure out either but I'm with you man, I thought of that right away.. Would a stuck BOV exhibit a complete loss of boost..?? It's a VRSF CP with HKS BOV, same as myself and many others on here.. I've yet to read a thread on that happening though so kinda skeptical on that instance..