Fuel pump questions Help

[flattie]

Ok I have the holley hp 150 fuel pump -10 lines going from the tanks to the pump from the pump to the carbs I have -8 along with a fuel log at the carbs. Brand new fuel pump only a few mins on it. Set the fuel pressure at 7lbs running it up to 4500 rpm or so all of a sudden its at 3lbs down to 0. How can I decide if the pump is running out of fuel and I starved the pump or If it is something else? The only thing that is new with my setup this year is new Quick fuel carbs and this fuel pump. and I moved the fuel pump to a diffrent location. But the pump is not higher than the tanks about in the middle.

[jbone]

My buddy spent a lot of time trying to diagnose a similar problem. His gauge showed major fluctiations in pressure and sometimes showed 0-3 lbs like you.
It turned out to be a faulty gauge. So consider trying a different gauge to verify the readings are acurate.
J

[flattie]

Not the gauge it simpley runs out of gas and shuts off

[Morg]

Pump some fuel into a bucket. Measure how much in what time. Move the pressure around & put a valve on it to put back pressure on the pump. Running out of fuel is bad.
Be careful while doing this. No smoking.
Also check your pick up in the tank.

[VDRIVERACING]

If you changed plumbing, there's always the chance of some cuttings in the lines, or even in the pump. You didn't mention a filter upstream of the pump... has that been checked out for retrictions?

[YeLLowBoaT]

check your tank vents as well.

[bigheavyd2]

I had a brand new pump right out of the box and it was bad, or try another pump, or try pumping out of a 4 or 5 gal tank and see if it run out.you just never know?

[Fiat48]

check your tank vents as well.
Best place to start.

[78Eliminator]

Clogged fuel filter will do this too.

[GofastRacer]

Sounds like everything was working fine before the new carbs and pump????, so that means new plumbing, were the new lines checked for debri after the fittings were installed??, good chance there are little chunks of rubber clogging the lines??. Now if this new setup requires more fuel than before and you have side tanks with flip top vented caps that may be the problem, try making a run with the caps open and see what happens!..

[flattie]

Well pumps great fuel from the passenger tank and very little from the drivers side tank. So the braided line is fine. Think the pickup in the tank is sucking air. Will keep you posted need to take the tank out tom

[GofastRacer]

So I take it that there is no problem when running on the drivers side tank then???, if so I'd still make a run with the cap open on the passaenger side tank and see what it does before going thru the hassle of taking the tank out!..

[flattie]

Drivers side tank is the one that is the problem. I had the stainless bung welded last fall something must have happend to it when he did the welding or when the polish shop buffed them

[GofastRacer]

Ooops that's what I meant,LOL.. Then maybe there is some residue plugging the line up??? did you wash the tank out before installing it??..

[MKEELINE]

Do the tanks have pickup tubes or bungs on the bottom of the tank?

[flattie]

the tank has pick up tubes on the top if its messed up Im going to plug the top and weld in a -10 bung on the bottom. Sucks if I had a fuel line break it would be all over the place. Your thoughts???

[MKEELINE]

I had a similiar problem awhile ago. My tanks had pickup tubes and at idle I had fuel pressure, when i would start to accelerate the fuel pressure would drop to zero. This was only happening on one side only. The problem was a piece of the baffle in the tank broke off and as ht eboat went forward it slide back and blocked off the pickup tube. I shit canned the tubes and welded -10bunges on the bottom of each tank. I also put a shutoff valve on each tank. No more problems, atleast with the tanks.

[flattie]

Well it appears the pick up tube got pushed to the bottom of the tank and would not let the fuel through. I had to hook a slide hammer to the the fitting and now she flows

[GofastRacer]

Glad to hear it was an easy fix!..

[cyclone]

If its a Volumax pump then that particular fuel pump has to have a steady supply of fuel going into the BOTH inlet fittings on the pump at all times for it to maintain prime and pump fuel. If either inlet loses its fuel supply the pump will not work properly. i had the same pump and it was a pain in the ass trying to keep fuel going to both inlets all the time. i ended up tieing both inlets together with fuel line and a t-fitting and then a single line from there to my fuel tank switch. Oh yeah that pump will not suck the fuel either so its got to be below the level of fuel in the tanks.
hope this helps.