HHHEEEEELLLLLLLPPPPPPP!!!!!! Update- problem unsolved again.

[SirRobyn0]

The problem has come back and I'm not sure what to go to now.

Well if it's pretty much the exact same thing it was doing, I'd be look at that fuel pressure regulator and vacuum line to it.

 

[fast_n_low86]

I've gone over all of those. I'm wondering if I should remove the return line from the regulator and deadhead it so it keeps the fuel up by the motor instead of sending it back to the tank

 

[hogdaddy]

Don't use the regulator vacuum connection.

 

[Turbo4whl]

LS engine, no fuel pump on the engine block? Where is you fuel pump? Electric pumps not in the tank don't like heat.

Remove the gauge from the regulator, add a hose and temporary move the gauge up on the cowl where you can see it. Engine is running out of fuel, you need to know why.

 

[squaredeal91]

If you have a rubber fuel hose connection before fuel pump it can suck air making fuel pumps efforts seem worthless. Even if it's metal all the way to tank I've seen many times it Sucking air inside or the pickup sick fell off etc. This is what I would investigate first if it's for sure fuel starvation. Try running it off of a gas jug underneath the hood or long hose with jug in cab to see if you can isolate the issue. Someone mentioned removing the regulator,maybe that will change symptoms at least?

 

[fast_n_low86]

LS engine, no fuel pump on the engine block? Where is you fuel pump? Electric pumps not in the tank don't like heat.

Remove the gauge from the regulator, add a hose and temporary move the gauge up on the cowl where you can see it. Engine is running out of fuel, you need to know why.

Fuel pump is an inline pump made for carbureted Engine. I have it mounted down on the frame underneath just before the tank selector cluster, sits about level with the bottom of the fuel tank.

 

[fast_n_low86]

If you have a rubber fuel hose connection before fuel pump it can suck air making fuel pumps efforts seem worthless. Even if it's metal all the way to tank I've seen many times it Sucking air inside or the pickup sick fell off etc. This is what I would investigate first if it's for sure fuel starvation. Try running it off of a gas jug underneath the hood or long hose with jug in cab to see if you can isolate the issue. Someone mentioned removing the regulator,maybe that will change symptoms at least?

I am running all steal braided 6an fuel line from the carb to regulator, to pump to tank selector cluster.

 

[fast_n_low86]

Don't use the regulator vacuum connection.

I pretty much did before and that started the whole issue. But I'll give it a shot

 

[Juggernaut]

Can't help you with the fuel problem, but I will tell you to be careful with those triangle filters. I was messing with my engine and it backfired through the carb. When it did it burnt the element, and the filter element started falling apart from the inside out. I never knew it until the engine started running real bad. Had pieces of filter element everywhere in that engine, including the oil pan and bearings

 

[Turbo4whl]

Fuel pump is an inline pump made for carbureted Engine. I have it mounted down on the frame underneath just before the tank selector cluster, sits about level with the bottom of the fuel tank.

How close is the exhaust system? Heat is an electric fuel pump enemy. Your symptoms are typical of a failing fuel pump. Yes you could be sucking air on the inlet side of the pump, but a small leak, the fuel and air reaches the carb fuel bowl. Fuel stays in the fuel bowl, any air goes out through the fuel bowl vent.

You need to see what the fuel pressure is when the engine leans out. That is why I said move the pressure gauge where you can see it driving.

The air filter is not the problem. If you are not getting air in, your air/fuel mixture gauge will show a rich mix.

 

[fast_n_low86]

Can't help you with the fuel problem, but I will tell you to be careful with those triangle filters. I was messing with my engine and it backfired through the carb. When it did it burnt the element, and the filter element started falling apart from the inside out. I never knew it until the engine started running real bad. Had pieces of filter element everywhere in that engine, including the oil pan and bearings

Thanks for the heads up. It did the same and I've now taken it back off

 

[hogdaddy]

I pretty much did before and that started the whole issue. But I'll give it a shot

Per Holley: "If regulator is equipped with the vacuum line connection on the top, this can be connected to full manifold vacuum to slightly decrease fuel pressure at idle and cruise. This is a requirement on forced induction engines, so that the differential fuel pressure stays constant under boost."