A couple thoughts:

1.) What's your fuel pressure?  Should be 39-42psi with the vacuum line disconnected.

2.) 14-15 A/F ratio would still be considered lean during many operating conditions.  That's what you would want on a light load cruise.  During acceleration it should be richer than that (12.5ish).  On start up it will also be richer, especially when the engine is cold (could be as low as 8 in the winter).

3.) Has it been sitting?  The ethanol in today's fuel has a nasty habit of causing injectors to stick if a vehicle sits for too long.  When in doubt run some Seafoam through it. 
 

 i have a 180 degree thermostat
I usually start the car at least once a week. 
I will have to get a gauge on the fuel pressure, might be a trick to hook up, since the intake covers most of the fuel rail.
I will get some Seafoam
It only does this when it is cold although it was doing it when the temp gauge was about 150. 
Afr has a heated O2 sensor

Ya know...........some people refer to a carb as a 'controlled-leak' !
Jus say'in........
6sally6

I have following:

stock foxbody fuel rail
stock pressure regulator
192/195 thermostat
stock calibration ECM (NAPA remanufactured)
stock intake manifold with inlet opened up to 70mm
stock Mass Air Flow sensor 60mm

Oxygen sensors are in midway of header collector where they merge and the flange.

The F150 runs great on the Holley carb and Duraspark ignition.
It doesn’t reek of gas either.

Last edited by Nos681 (6/20/2023 6:53 PM)

Bearing Bob wrote:

I love the smell of gasoline in the morning.

 
I can remember as a kid touching and sniffing the weeping dash gas gauge on my dads model “A”
Today’s gas don’t smell as good as the gas in days of yore!

Where is the air filter?  Could it be picking up air currents from the cooling fan?  It took us years to figure that out on Fox body cars. 

You might try rigging up a shroud to shield it from the air currents from the fan.  Turns out there was a reason Ford put the filter in an airbox on the Fox cars.  We discovered the air currents from the fan were negatively effecting the idle and transition throttle.  A shield solved it, or we would move the air cleaner to the inner fender (though this necessitated a recalibrated MAF, or later we learned to fix the various tables with tuning). 

If the engine is basically stock a 70mm TB is too big.  Stock I believe is only 55mm.  The old Motorsports TBs were 65mm and worked well without needing to mess with anything (though it was a good idea to gasket match the hole in the upper). 

With a code 95, I would inspect wiring at fuel pump relay, inertia switch, and fuel pump.
Verify voltage is steady while moving wire harness.
Check ground connection for fuel pump too.

I have a 70 mm throttle body and stock 60 mm MAF.
The opening on intake was made to match 70 mm throttle body.
Using a stock remanufactured Napa A9L.

When my factory A9L failed, the fuel pump never cycled on at start up.

I think i found the source of most of the problems i am having.


Feel kind of dumb taking so long to find it. Started spraying carb cleaner on everything till it sped up, and there it was.
Haven't had a chance to test drive it yet, but the AFR readings are a lot more in line with what i think they should be.
 

HudginJ3 wrote:

Bearing Bob wrote:

I love the smell of gasoline in the morning.

 
Ave Gas

 
Could be a source of my issues but as a kid I liked the smell of carbon tetrachloride!