AlexG13B

iTrader: (7)

well dampner didn't fix my problem :/

dk_davis

Did it change the characteristics of the problem at all?

Carlos Iglesias

iTrader: (6)

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

AlexG13B

iTrader: (7)

I dont think so

AlexG13B

iTrader: (7)

10ms refresh rate. fuel pressure looks smooth but intake kind of wavy?

Slides

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?

C. Ludwig

iTrader: (27)

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.

TeamRX8

iTrader: (2)

mountain <—> molehill

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

gxl90rx7

iTrader: (1)

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