Bad fuel pump?

[comet_666]

I have this tank
https://www.tanksinc.com/index.cfm/page/ptype=product/product_id=395/category_id=68/mode=prod/prd395.htm
And I believe (I don't remember) this pump
https://www.tanksinc.com/index.cfm/page/ptype=product/product_id=605/category_id=61/mode=prod/prd605.htm

I noticed while driving the pump gets pretty loud, I usually chalk it up to being low on gas, it's not really that bad. The other day I noticed while sitting at a light it was making a up and down noise, I happened to have the fuel pump up on my fi tech handheld unit (fuel pump) and saw it drop from like 92 to 80 then to 95 back down to 90, and the noise changed as I saw the numbers jump around, was weird I have never heard it do that before.
Fast forward a handful of days and I drove it out to a park yesterday, same thing, sounded funny but it died on me in an intersection. First time its ever quit on me, it fired right back up and away I went. I was doing like 40 down a road and poof..car dies, I coast to a gas station. I sat there for about 5 min, fired it back up (smelled pretty bad of gas at this point) and made it back home on the expressway just fine. IS the pump going bad?
I should mention that last Tuesday I got the electric fan setup in my car finally, is it possible that it's wired in a way that is pulling power from it? It is wired to the acc on my dakota digital box, that is the only thing that has changed.

[69Chrgr]

I just replaced the pump in my friends 68 Charger with that very fuel system from Tanks Inc. I do a lot of Holley Sniper conversions, and found that the Tanks Inc. setup, or at least this one, had a foam filter that sat inside of a rubber bladder. This may have caused premature failure on my friends as the pump had to work much harder to overcome those two obstacles. On the Holley EFI tank which does come from Tanks Inc, there is no foam filter or rubber bladder that the pump sits down into. It just uses the mesh sock on the Aeromotive 340 pump. I removed these two items and just used the sock that the pump comes with for replacement.

[comet_666]

So your saying it's something in the tank itself that the pump sits in that could be causing it to have gone bad?

[metallicareload99]

Does your FiTech show actual fuel flow (mine does)? Which parameter are you looking @ on the FiTech? Also are you 100% sure you don't have the "GPA-4" pump?

IF you have the GPA-4 did you set the fuel pump duty cycle to 100% on the FiTech? The numbers you posted suggest to me that the FiTech is in pulse width modulation mode. The GPA4 uses a gerotor type pump that shouldn't be used in pulse width modulated mode.

FWIW I drove around for 5,000+ miles on a GPA-4 pump and the FiTech set in pulse width modulation mode. It did seem like the pump got louder over time, but it never failed, I put in a new pump after switching over to the 100% duty cycle

[comet_666]

Oh geez, I am not sure which pump, I reached out to tanks inc to see if they have a copy of my invoice (I have the number not the actual invoice itself)
I never looked at that setting, I have "fuel pump" and "fuel flow", but in this case I think I had fuel pump on my large gauge on the handheld which is where I saw it bounce around then drop off to 0.

[metallicareload99]

Another thing, after installing the new pump the noise level seemed the same It seems like there have been a lot of changes over the years with the FiTech display, but I gotta believe somewhere it'll show fuel flow. A data log could be helpful here also

[comet_666]

Here are my settings, Didnt see option for pulse width modulation mode.

[comet_666]

tanks inc said same thing you did, pwm probably killed the pump. They suggested the new series 5 pump which works with pwm and fi-tech
https://www.tanksinc.com/index.cfm/page/ptype=product/product_id=624/category_id=61/mode=prod/prd624.htm

[metallicareload99]

Here are my settings, Didnt see option for pulse width modulation mode.

Yeah, it's been a long time since I altered that setting. Can you change those PWM_____Flow numbers to 100 in that last picture? That "should" do it, but as I recall I only had to change one number.

I don't know why I didn't switch to a turbine pump when I switched out my first one. Other than the I knew it would fit and the GPA4 pump is sized well for what I'm doing....for now.

[comet_666]

According to Fi-Tech they say don't do it. I may tinker with it just out of curiosity but with the new series 5 pump on the way not sure it's worth messing with it.
It also answers another question I had about stiff pedal.

[comet_666]

Also, just got this from tanks inc
They will work for a while, especially if you do a lot of highway driving and not a lot of idling.  As the Fitech PWM only engages at idle.  The pulsing cause excess where to the rotor and gear in the pump and once it gets to a certain point it starts to cavitate and not function correctly.  Sometimes it happens faster than others.

[metallicareload99]

Also, just got this from tanks inc
They will work for a while, especially if you do a lot of highway driving and not a lot of idling.  As the Fitech PWM only engages at idle.  The pulsing cause excess where to the rotor and gear in the pump and once it gets to a certain point it starts to cavitate and not function correctly.  Sometimes it happens faster than others.

That's a good point there! Because I have a solid roller cam, I try and follow a routine: 10 minute warm up to operating temp and about the same amount of heat soak. And then I try to avoid idling/traffic as much as possible. Always moving

[68CoronetRT]

I read through some of this post and maybe you solved this but the Fitech changes the voltage to the fuel pump and those pumps want to see constant voltage. One of the reasons I changed to a Holley Sniper unit. I bet that voltage changing is what killed your pump. This is also why you want a return line back to the tank. This allows the fuel pump to just run at a constant speed and recycle the fuel the unit is not burning.

[comet_666]

I have a return line running back to pump and just swapped out the pump for a new series 5 pump (quieter too!)