Identify a whine/whistle/squeal sound

A few times now my '00 has made a whine/whistle/squeal sound while running. My guess is that it's the fuel pump but if anyone has thoughts I'd appreciate them. The car has a Whipple CTSC. I have ordered a fuel-pressure sensor for the Zeitronix data logger, but that's still a day away. There is a replacement fuel pump on its way to me. I should add that it seemed like the AFRs were higher than normal, so I've been staying away from boost until I get that fuel-pressure sensor; but without logs I don't yet know if the AFRs are actually abnormal. I will collect logs once the sensor is in place.

The sound so far has started while driving and has gone away after I shut off and restart the engine. It does not appear to be strongly related to engine speed, although the pitch decreases slightly when pulling away from a stop. It just occurred to me that it might be A/C related, but it didn't make the sound in the garage just now, so I will have to see if engaging the A/C compressor makes any difference next time the sound comes back. I suspect not since I would have thought that would depend strongly on engine speed.

Anyhow, this is a recording of the sound as I was headed into work today:
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WAG #1 : AC idler pulley? Verify by removing AC "fan" belt. If so, search on Prime for the bearing instead of replacing the entire assembly. Disclaimer: my hearing is not what it used to be, especially over a small computer speaker.

My guess would be fuel pump as well. You could try to pull the vacuum line to the fuel regulator if any change occurs. The pressure sensor will be helpful.

sounds like pulley/belt noise

Thanks all. I will try to poke around the engine compartment when it's making the noise. And will report on fuel pressure once I get the sensor installed.

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I put in the pressure sensor and as far as I can tell, it shows that the fuel pressure cannot keep up at high RPM; at low RPM, the fuel pressure seems to track the boost pressure pretty well:


I don't know that it's related to the whine, but I'm planning to go forward with replacing the fuel pump as soon as I can use up the full tank of gas.

SOLVED: new fuel pump

Update: I bypassed the fuel-pump-resistor relay (rather than bypassing just the resistor itself) and had a new Deatschwerks DW200 pump put in, and now the noise is gone and my AFRs are back to something reasonable. I posted my logs over in this thread. Thanks again for the comments and help. -Jason

Jason,
How much does one of those pumps cost?
Brad

OLDMNSX said:

Jason,
How much does one of those pumps cost?
Brad

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Very inexpensive really. $112 shipped.

I'd like to add that I would seriously consider using the DW300 pump rather than the DW200 with the stock CTSC setup. With the extremely high pressures called for by the CT pressure regulator, the DW300 would push more fuel at high RPM.

My Walbro 255 is almost dead/failing. I've been trying to figure out the best replacement. I'm leaning to the DW300 for the added fuel volume.

BrianB said:

My Walbro 255 is almost dead/failing. I've been trying to figure out the best replacement. I'm leaning to the DW300 for the added fuel volume.

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You have 550 cc/min injectors and an FIC, right? That's my setup, and because of that I don't feel like there's any need for the DW300. The DW200 supports over 600 hp so it seems up to the job so long as you aren't asking it for > 100 psi.

I used to have the FIC and 550's. The car ran so bad I had to get rid of it. I put the CT stuff back in and it ran great! But then now the pump failed. So I need a pump that's good to go to 100psi.