Fuel Tank/Pump Issues

[Macster]

Using behind seat EEC tank in my 1972 C-10 3/8 line to pre-filter (100 micron) out to Pump (pierburg), to post filter 35 micron) to 5.3 vortec treuck intake fuel rail. 5/16 return linr to sender return line.

Problem: fuel pump starves intermittently.

Since I have a pre filter, could I remove the sender sock/strainer?

i am thinking the pump might be trying to draw the sock in.

Any one experience this problem?

[68GMCCustom]

where's the pump mounted? is the tank brand new or used? are you sure your filters are rated for your psi@gph used?

[cjohnson6772]

Originally Posted by Macster

Using behind seat EEC tank in my 1972 C-10 3/8 line to pre-filter (100 micron) out to Pump (pierburg), to post filter 35 micron) to 5.3 vortec treuck intake fuel rail. 5/16 return linr to sender return line.

Problem: fuel pump starves intermittently.

Since I have a pre filter, could I remove the sender sock/strainer?

i am thinking the pump might be trying to draw the sock in.

Any one experience this problem?

That is not a baffled tank. My guess is that you're starving it going around corners or when below 1/4 tank. That is why I'm leaning towards under bed tank. Otherwise I would reuse my in cab.

[Macster]

Pump is located drivers side on frame
I purchased the fuel components from Turnkey Engine supply out in Ca. the system they use in swaps:
Up to 450 HP* Billet Clean-able 100 Micron Pre-filter* Pierburg Quiet Pump* Bosch 35 Micron Post-filter*
I contacted them and they recommended removing the sock.
Oh, new tank in 2008, so the sock could have picked up some trash.
Just trying to see what corrections swappers have made; I know I am not alone on this issue.

Mike

[Macster]

The starvation was on a flat straightaway and going around 60 mph.

It has been intermittent; this morning she ran fine to work.

[BR3W CITY]

Don't EEC tanks require a vented cap, or some sort of venting? I'm wondering if you are vapor locking your tank and making the pump starve.

My other thought is to just try it without the pre-filter; there are tons of filter options, but it seems like 85% are designed for carb'd apps and will actually cave the filter element under FI pressure. FWIW, many people don't bother with the pre filter...if your tank is clean (no rust etc), there isn't a huge need for it. All a pre filter does is prevent rust or sand or scale (were it to end up in there) from hitting into the pump...but 95% of the time the pump just passes it right through and the higher-micron filter catches it.

The final thought is that somehow the distance between the tank and pump is too great and the suction is finding a restriction somewhere, either collapsing the line, cavitating, etc. It might be worth un-hooking the fuel feed after the pre-filter, and putting the pump into a small bucket of fuel. This will let you test the pump, without restriction, distance, of filter issues and make sure there isn't something else going on.

Has your truck thrown a code after stalling/starving?

[Macster]

I have a vented gas cap and a vent line going to a charcoal canister under the battery.
I would like to keep the pre-filter; and would rather test the theory of the pick-up tube sock deteriorating; and maybe remove it.
You are correct with the pre-filter being a possible issue though and ran the theory that in-tank pumps only have one filter btwn the pump and the fuel rail, so why run 2?
No codes other then Vss, but I am running a TH400 and have not hooked up the Dakota Digital Pass-through Pulse Generator; hopefully that clears the code.
might bend a new feed line from the sender to the pre-filter; I do have a AN to tube fitting and a section of -6 AN braid to the pre-filter. I would be better off with just a single line; could ealleviate potential problems/leaks.

Will let you know what I find out.
Thanks

[eagleuh1]

I ran a cannister pre-filter before my Corvette filter/ regulator. Between pump and regulator. Never had a problem with it. All mounted close together inside frame rail below driver. Maybe your problem is the prefilter before the pump. Too much suction restriction maybe. Good luck with it. Jim

[C10_ustacould]

Originally Posted by cjohnson6772

That is not a baffled tank. My guess is that you're starving it going around corners or when below 1/4 tank. That is why I'm leaning towards under bed tank. Otherwise I would reuse my in cab.

I have the Boyd Welding tank with an external pump and when the level is near 1/4 of a tank and I make a right turn to stumbles and then picks back up. I am thinking about selling this tank/pump to purchase another with an internal pump.

[eagleuh1]

Get the FI tank he makes. I have one with zero problems when taking off, stopping or hard cornering.. Put an internal vent in the filler tube though to prevent the burping when filling problem. I'm running flexible fuel tubing in mine.

[BR3W CITY]

If you already have an unbaffled tank and external pump, just get tank foam, don't bother with a whole new tank. The foam takes up barely any capacity, and prevents the sloshing etc. I have a hand fabbed 16gal cell, tank foam only and have never had a fueling issue down to almost dead empty.