[V8] Fuel Pump noise

[Professor GT gmail]

Allan,

Low voltage to any motor will cause degradation of performance of the motor itself, AND an increase in current flow in the circuit. The reduced voltage (push) causes the motor to run slower. This then makes the motor labor more (noisier). Because of both, the current draw goes up, which increases heat in the motor, which shortens life. Now a fuel pump is cooled by the fuel, so temp in this case is not typically an issue. But to confirm all of the above a current draw measurement would be best. Then, once full voltage is available if the pump is still noisy we'd have to blame the pump itself, which if internal binding, poor brush contact, or a tight pump itself is the culprit, again current draw will be higher than "normal". The problem is getting a draw spec. Many times with things like this, the only way is to measure a "known good" unit to use as a baseline. I'm sure you have done this with other things, so I know you can relate to what  I'm saying. Fuel pump noise can be a challenge, as things like the intake sock being mis-positioned can contribute to the issue as well.

My V8s have been sleeping for some time now, and as I prepare to get them out of mothballs, I hope I do not run into issues from rancid fuel. I'm getting closer to beginning the 4.2 swap, and can't wait to get started.

Unfortunately I was laid off this Monday, so my focus right now is on job hunting. I hope to land something substantive soon, but in the meantime I've has a few offers to spin wrenches and do some training as well. It will be a trying time, but I have to stay positive. My solace is burying myself in V8-ness! This takes my mind off the worrisome stuff, and gives me a sense of accomplishment and pride, but you already knew that!
By the way, you beat me to it, but the red engine parts look excellent. Guess I'll have to go with blue anodize on mine!

Gerard

Message: 3
Date: Wed, 25 May 2011 17:57:19 +0000 (UTC)
From: allanvega at comcast.net
To: Professor GT gmail <CavalloGT at gmail.com>
Cc: V8 at audifans.com
Subject: Re: [V8] V8 Fuel Pump
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   <1553510383.859210.1306346239323.JavaMail.root at sz0030a.westchester.pa.mail.comcast.net>
   
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After reading this, I decided to go out and check out why my new Bosch fuel pump was so noisy. Voltage @ battery with engine off was12.6 volts, with engine running it was 13.47 volts.. 
Now @ the fuel pump I have 12.64 volts with engine off, and 12.65 with engine running. That 12.65 jumps to 12.82 if I add a temp ground wire. I stopped there because I ran out of time, but I suspect the supply voltage to pin 30 of the fuel pump rely may be the culprit. I will continue diagnosing either later tonight, and report back later. Allan

Thanks,

ProfessorGT
(Sent from my iPhone4)