Fuel Pump Whistle

[badams118]

I've noticed my fuel pump making a whistle or ringing sound when I let off the gas lately. It's as though it is releasing the pressure built up when I give it throttle. I can make it do this by revving it a bit at idle or while driving.

I also notice that my AFR gauge sweeps rich when I do this, which would be consistent with it releasing built up fuel pressure. I will try to get a data log & maybe a video of I can pick it up that way.

[www.cp-e.com]

Originally Posted by badams118 I've noticed my fuel pump making a whistle or ringing sound when I let off the gas lately. It's as though it is releasing the pressure built up when I give it throttle. I can make it do this by revving it a bit at idle or while driving. I also notice that my AFR gauge sweeps rich when I do this, which would be consistent with it releasing built up fuel pressure. I will try to get a data log & maybe a video of I can pick it up that way.

Let me see if I understand...

When you let off the gas you hear a hissing sound coming from the fuel pump area under the hood, and your AFR gauge goes rich? That's definitely strange! Please do grab a log of the event if you can and we'll see if we can't figure out what's up.

[badams118]

Thanks, I'll post something as soon as I have the chance. The sound is kind of like tapping a pipe with a wrench.

[badams118]

Fuel pressure looks good. I am seeing 420psi at idle & 1600+ at WOT.

I'll try to get a video of the sound later.