Hi guys, I have a holley inline high pressure fuel pump on my new TPI 327 setup. The pump is so loud on solid mounts I can't help but hear it at all times. The pump runs at constant speed, but occasionally when I'm out driving, I'll hear the pump slow down for a few moments and then pick back up. Is this normal, and the pump is just bogging down when the regulator is sending it a strong demand for fuel, or should I check my ground connection or the pump itself (I got it used). Inline electric pumps scare me.

 

If it's slowing down at idle speeds, it could be the voltage dropping from the alternator not providing enough juice at low RPM. Just a thought..

I might have a better answer in a week or two when I get my TPI'd Chevelle running.. :-)

-Dave

 

Hmm, you know that is possible. I bet the pump is slowing down when the fan kicks in (I'm using a mid 90s Ford T bird dual speed fan, its huge-mongous, and I'm having the computer switch high speed only above 190 degrees. I bet this thing draws 40 amps continuous). I figured my 105 amp brand new alternator, and the fact that I have no a/c, accessories, or fancy electrical equipment on this 77 camaro would mean I'd never see voltage drop. Idling with the fan on is definitely working the alternator though, I was squealing the alternator V belt when the fan would kick on when I didn't have it tight enough. I'm going to run a better ground to this pump and see what happens, I really won't be too happy if it strands me somewhere. Hopefully this is just normal behavior w/ all the electrical draw I have.

 

Check the fuel pressure, see if its consistent. Some pumps sound different under loads and temperature changes, but deliver the same.

 

What in-line pump are you using? I'm not a fan of dropping my gas tank if I don't need to.

 

I am using a MSD 2225 in line pump. I put it under the hood on the fender, because I drive in deep snow and didn’t want the wires to get broken off. Some people said it would not work under the hood. Mine seems to be working fine under the hood; the only problem is the noise.

 

Your gons need to pull the one out of the tank anyways.

 

Mine just hums loudly all the time and it's mounted under car in the rear. BTW it's a vortex t-rex and the factory fuel pump is still being used

 

Tell me more about this Tbird fan please. Got any details or pics of this or how you did the computer switching?

 

Blown85, see the brightly colored 77 camaro up top? Thats the car I have the 327 TPI in, with the T bird fan. I have no idea about using it on a 3rd gen. I have a painless wiring harness for my MAF tpi, which provides a ground for the fan relay (only one, no provision for 2 fans). I just set up a relay that has everything except ground wired, and the computer provides that ground when it wants the fan on. I need the high speed whenever the fan is on, for some reason my little 327 runs slightly on the warm side of normal even with a 3 row huge radiator. Here's a pic anyway. I have the fan zip tied in right now, I have yet to make actual mounts for it. Thats the relay sitting on the battery, I wasn't expecting this to work, so I didn't finalize the wiring. Surprise, it works.

 

Several things make your pump humm under diferent tones like current being drawn from other accessories, heat , and the pressure it self being changed from the regulator.
When the pump is building up pressure it will make higher pitch hummm then once the peak pressure is met by the regulator the pump gets slowed down under load then you start hearing the differences.
If it bothers you that much do what I did and fasten the pump down with rubber insulated clamps if that isnt possible maybe try placingsome type of gasket or rubber o rings under the pump it self before bolting it to bare sheet metal after all that is said and done be sure to maintain a short and solid ground wire.