I have conversed before regarding my 350 Chevy motor with twin turbos and still have not been able to fix the problem. This is long story, but the short version is that I built this motor with everything new including a non-radical roller hydraulic cam. It smokes backish, blue smoke from the left bank out the exhaust when accelerating. No smoke at idle. I have been through the gamut of checking everything from the turbo oil drain to the PVC system with no luck. Today I noticed that my oil has a gasoline smell and is a bit diluted. I have only driven the car about 50 miles since rebuild. I have 8 lbs. of fuel pressure at idle and am using a boost referenced fuel pump regulator. My thinking now is that I am over fueling the mighty demon 750 blow through carb???
any suggestions?
thanks

 

You don't need 8 psi, 5-6 is enough. 8 is just asking for the needle, and seats to leak, and gains you nothing unless your needle, and seats aren't large enough to keep the bowls full in boost. If you have black smoke, it's definitely getting more fuel than it wants. I don't remember, do you have a wide band?

 

Here is my set up. #ad

 

Mnix
Here are specs on my camaro

Gen 1 350 with all new standard components; standard crank, rods, standard pistons, rings, bearings, cam and crank

New HOWARD'S SBC Chevy Retro-Fit Hyd. Roller 270/278 495"/500" 108° Cam Camshaft Kit

New Proform 66906C Stamped Roller-Tip Rocker Arm 1.5 Ratio 3/8 in. Stud Clamshell

New Mighty Demon blow through 750

New Eldebrock polished intake manifold

New Elgin 1.94" Intake & 1.5" Exhaust Valve Set

700r4 Transmission freshly serviced

New 2300 RPM Stall converter

New Felpro gaskets

New Electric water pump

New Melling high volume oil pump with pick up

New Acel HEI Dist.

New MSD 6al2 programmable ign

New Cloyes timing gear bearing for roller cam

Ported and polished heads

New plug wires

New Holley 140 GPH electric fuel pump

New Holley 4-9 PSI adjustable fuel pump reg with return port, boost referenced

New Twin t-3/4 turbos

New MSD Tach converter box

Flowmaster

Mufflers, Big Block II 70 Series, 2 1/2 in. Inlet/2 1/2 in. Outlet, Steel, Aluminized

Corvette Fiberglass tail light panel and quad exhaust tips from C4

Custom dash and all new gauges including boost and oil temp

New door and window rubber molding

Custom gear shifter for 700R4 transmission

Electronic wireless exhausts cut-outs on both sides

4 New oversize Tires

4 wheel disc brakes

New Front brakes

Posi-traction 3:08 rear

New Champion 3 row aluminum radiator

Driver and passenger seat recovered

 

Hi minx
Tried disconnecting boost reference host to hat. Absolutely no change in anything. Even fuel at accel was fine without the regular to the hat????????

 

For anyone to know where your timing is, they need your base timing , without any retards from ignition control.

So you say "fuel at accel is fine". What does a wideband say? Idle, cruise , and wide open.

 

Them mufflers ain't helping any. Smoke through the cutouts too?

 

Fuel will seem fine until it empties the bowls and goes lean. Fuel pressure needs to be around 6psi, never over 7. And the regulator hose MUST be above the throttle blades, like in the hat or the charge pipe.

 

What is perfect fuel pressure at idle?

 

Fuel pressure won't affect the tune as long as the needle and seats aren't leaking and the bowls are full. 5-7 psi.