So I decided to check my fuel pressure tonight. At idle, a consistent 39 psi, when unplug the vac line off the regulator it goes up to 47. Checked my engine vacuum at idle, 21, then used my MityVac on the regulator to simulate various vacuum loads from 21 to 0. It was consistently going up as the vacuum went down, is this correct?

The other thing I did notice was that after shutting off the car, it quickly dropped to zero fuel pressure in about 5 sec or so. It is not a stock fuel pump, but a Racetronix (I think Walbro) pump that I installed with the trap door method years ago. What would cause the immediate drop in fuel pressure, bad check valve in the pump, or could it be another reason as well? If bad check valve in pump, does that mean new pump or does it not really have an effect on the car?

Thanks in advance!

 

Pressure is normal. Unless you have cold start problems, you don't have to worry about the pressure bleedding off quickly. There can be numerous causes for that. There is info on my Tech Page for isolating it.