well dampner didn't fix my problem :/

Did it change the characteristics of the problem at all?

Another perspective on fuel pulsation for your consideration from a friend...

I dont think so

https://cimg7.ibsrv.net/gimg/www.rx7...31819dbb14.jpg
10ms refresh rate. fuel pressure looks smooth but intake kind of wavy?

Look up signal aliasing, your sample rate needs to be 10 times or more the target frequency to get a true idea what is happening, you may be seeing different points in the intake resonance cycle, it's more obvious if you sample from one runner, RICE RACING had a perfect example in one of his racelogic graphsyears ago before he got banned nearly everywhere then sold pre-prototype housing shredders as worlds best steel seals. Is signal damping the same on each channel in the software?

Are you sure it isn't a staging/wall wetting issue on transition enrichment? And/or injector phasing combined?


What happens if you go WOT from 1000rpm, lean at the same point?

Great points. I'll also add that, mechanically, the pressure regulator isn't going to react with the same frequency as the intake pulses and it's certainly not going to influence the pressure of the whole pressurized volume of fuel in the system as quickly.

That said, it's common to have dips or peaks for a given load in the VE curve under vacuum at lower revs. There are resonances that happen that need to be accounted for. Once load and revs come up, the curve will flatten. But under vacuum below 3500, expect there to be dips and peaks. Give the engine what it wants and don't think about it too hard.

mountain <—> molehill :dunno:

maybe a blessing even, if that’s all that’s going on to fuss over :suspect:
.

i was having a problem that seemed to be pulsation related, lean misfire at a 3900 rpm. I installed a radium FPR no difference. i am running a haltech PS1k, and found out when you upgrade firmware, you are supposed to immediately load a base map for that firmware, then import your previous map. that fixed the misfire. just posting this if anybody having similar issue