o2ws8

iTrader: (1)

I have the magnafuel 4301 pump and recently ive been noticing that after i run my car for an hour or so...My fuel pressure gauge starts flickering and so does the pump..My pressure be at 58psi and then it starts dropping to 55psi and it just be back and forth! It had never done that till recently...

Speed Density

iTrader: (38)

Are you sure you have enough gas in the tank?

Lonnies Performance

iTrader: (16)

Your pump is cavitating either because the fuel is getting hot or your prefilter is getting restrictive.

o2ws8

iTrader: (1)

Yea it be over half or so and it still does it! I'm thinking the fuel is getting hot...What can I do to keep that from happening??

Lonnies Performance

iTrader: (16)

A common problem with large pumps is fuel heating due to the constant high flow through the system. Keep in mind all the power going into the pump is converted to heat which heats the fuel. This is the reasoning behind pump controllers as they slow down the flow & lessen the power draw, keeping the fuel cooler. You can also run a fuel cooler in the return line to help somewhat.

o2ws8

iTrader: (1)

So what would solve my problem a fuel cooler or some sort of pump controller?

Avengeance

iTrader: (4)

With an external pump, say the Magnafuel in question, what kind of fuel temps are usually seen? Im curious.... Ill be running a similar system although with E85.

'Trust'

iTrader: (24)

Interesting. A Weldon Controller or something similar should get you squared away, control the power to the pump then just have it come on 100% at 3500ish.

o2ws8

iTrader: (1)

I use to have an aeromotive pump that use to do the same thing.I switch to this one cause it was suppose to be the ultimate street pump and its doing the same as the aeromotive pump.

RAACCR

Here's how we like to set-up our Magnafuel Pro-Tuner systems:
Insulate fuel tank/cell and lines from any heat sources
2 x -8 vents
-12 inlet with 7006 prefilter
Magnafuel ProTuner pump (usually 750's because the cost is so close for all of them)
-10 feed with 7008 filter
9950 regulator
-10 return with 11"X8.5"X1.5" plate style cooler
return fuel to corner of tank/cell furthest from the sump/pick-up

Alot of people don't spend the money and effort to set them up this way.
But, it keeps us from having issues like the OP's.

Avengeance

iTrader: (4)

Thats almost to the T the system Im building right now. Only difference is Im using -8 return and now, thanks to this post and info, Ill add in a cooler too!

Avengeance

iTrader: (4)

Im still curious... RAACR maybe you can answer... what temps do you normally see on return or in general?

RAACCR

-8 on the return will be okay. I usually regulate the systems down to ~35psi at zero boost/vacuum, so I'm bypassing alot more fuel at idle than people running stock pressures. But, even for that, -8 would probably be adequate. Reason for the low base pressure is because the pump volume falls off pretty hard at elevated pressures. We find that 35# base, with 1:1 boost reference, works perfectly with 1600cc injectors; the 750 pump and 1600 injectors both max out right around 1500 flywheel horsepower on our typical e85 applications.



I've never measured the temp on the return side, but we've never had a heat issue with that set-up. Alot of people consider it overkill, but I'd rather have overkill than problems.

LS1NOVA

iTrader: (12)

Do you have a part number on the cooler? Have you ever used the inline BG heat sink cooler?

Avengeance

iTrader: (4)

Great info right here...... thanks! I will also be using 160lb injectors... flow matched and averaged 1645cc @ 43.5psi FP. I will also be using E85 with the same pump. 1500FWHP is exactly what I wanted to hear.... plenty of fuel system for my goals. (900-1000rwhp)

RAACCR

B&M sells them under their part # 70272
Long & Tru-Cool sell them as part # M7B