xlint89

Rained all week end, so I never got it out to test yet.

While doing stereo upgrades I decided to throw the vacuum pump on the new anti-siphon valve again just to see what it takes to pull fuel from the tank.

Anti Siphon valve holds 1" of vacuum before allowing fuel to pass. Once I got to 2" the gas started coming out. And at 1" it would stop.

So, am i correct in thinking I need 2" of vacuum to get fuel out of my tank? Or is that 1"? Thanks

SB

iTrader: (1)

2”.
Did you add the mitivac exactly where the fuel pump would be ? Physical location and also rigging location ? Those may add some more resistance and thus add more vac “ to hour readings.

xlint89

I had it installed after the fuel pump to prime the lines and new fuel filter prior to start up. I had a hose press fit into the supply hose to fuel rail orifice. I was pulling fuel with 4" and the gauge would drop down to 2" after I stopped pumping. So it seemed to stop flow at 2" (after the fuel pump) and would pull fuel at 3"- 4"

That's why I tried it directly at the tank. So it needed 2" to flow there. Maybe gained 1" more of vacuum to pull fuel after the pump.

camptappakeg69

Fought with fuel problems with my mefi 1 502mag for.many years, although I had the much worse vst system, I finally cured it by taking all out and installing an aeromotive pump and regulator, I have i thread on here somewhere that details what I did. I set mine at 40 psi and runs like a champ!
side note, have you checked your tank vent...maybe not.letting the tank breath

xlint89

Thank you for the reply.

I would be very interested in seeing how you did the conversion. Might be the route I go some day.

FINALLY got the boat on the water for the first time.

Boat ran great. No stumbling, hesitation or anything. Thought I heard some whining, but took her out any ways and never skipped a beat. If something blows up, so be it at this point.

1998 Cobalt 252. 502 turning 5k RPM and a Mirage plus 23p prop. Speedo was reading 65 MPH. Not sure exact speed, but I'm pretty happy with the performance thus far.

Thank you guys for all your help with this issue.

xlint89

How can I install a dash mounted fuel pressure gauge on my engine?

I see Levorsi has a sender unit that it 1/8 NPT external thread.

https://www.cpperformance.com/p-1307...-0-100psi.aspx

On my fuel rail is the schraeder valve for installing a pressure gauge for testing, which also has external threads.

Is there an adapter, or does the sender mount someplace else? Thank you

PA.WOODCHUCK

I Never done it, but I wouldn't use the schraeder valve because doesn't sound safe. I'm sure others will chime in?

xlint89

Thanks for the reply.

There is no other place to install a sender unless I add a "T" between the fuel pump and the supply hose going to the fuel rail.

Not sure if that is even possible as the supply hose is a flared fitting with an O ring?

AllDodge

iTrader: (1)

Don't see a gauge providing you anything but something to look at while its running good. If pressure ever does drop you will know it even without a gauge. Then one can be attached to verify

That said, I would remove the schrader valve off the rail and attach some kind of a Tee fitting for the electrical sender to feed the helm gauge

xlint89

That's a good idea. Thank you.

I'm looking to replace the dash gauges on my boat, and will replace 4 small gauges with a large multi function gauge. That leaves 1 small (2") gauge hole open on my dash.

I already have a depth sounder and temp gauges built into my dash, so that would be a waste to install one.

I don't think an Ammeter would be useful.

A water pressure gauge might be useful, but not sure where to install a sender for it?

Hour meter gauge is kind of a waste as I have on installed in the engine compartment.

So I thought a fuel pressure gauge might be useful