When the car is cold and i start it my fuel pressure reads from 3-7psi.

When its warm its where i want it 2-2.5 ish.

I only care cuz when i start the car cold it sucks! PIG RICH. sputters around back fires etc. when its warmed up runs good tho.

I am running the stock SE F.I. fuel pump(suggested to be ok) with a mallory 4309 FPR with a summit liquid filed guage. My relay for the F.I. harness is jumpered so that the pump is on with the key in the on position.

I am thinking that the fuel pump itself is the issue. I am not fond of the FPR converting 60+ psi down to 2.5 reliably. I am thinking of purcahsing a high volume low pressure pump from mallory.

I have changed the fuel filter within the last 2 yrs.

So i am asking if anyone has seen this or has some thoughts on why this is happening

FWIW i have not yet installed a wideband, i have the AEM now but havent yet welded the bung in.

 

Change your fuel filter. Clean out your system with seafoam. Invest in a new pressure regulator.

Has anyone ever ran 2 regulators back to back to equalize the pressure better?

 

Its a new 4309 FPR the motor has less than 700 miles on it and so do all the components except the pump. the filter maybe has 2k miles on it.

 

im thinking of shimming the spring so its stiffer. Why is temperature a variable?

 

Well your seals and engine parts expand and contract according to temperature. So do the fluids I guess. Also I believe when gasoline is warmer or when the internals of the engine are warmer it takes less fuel to ignite?

 

I think im going to reduce my needle valve to a 2 instead of a 3 and see fi that changes anything.