Fuel Pressure Questions

[yellowred]

1990 325i Sedan (M20)

Generally when cold starting my idle is rough and around 550 rpm

When I blip the throttle the car rpm drops and the engine sputters before gaining rpm

Overall lack of power

old compression test results here: https://www.r3vlimited.com/board/sho...d.php?t=399036

I have replaced the fuel filter and the lines before and after the filter with R9 hose (was leaking fuel, the lines were dry rot)

I replaced the fuel line to the fuel pressure regulator and the vacuum line to the fuel pressure regulator

I installed an inline T to a gauge on the fuel line below the fuel pressure regulator. Setup as seen in this pic:https://drive.google.com/file/d/0B34...ew?usp=sharing using this gauge: http://a.co/6PNywuD

At idle (idling around 900) the gauge read ~38 psi stable

When the throttle was blipped the gauge would shoot up to 50+ and with rpm gain the pressure would drop back to ~38 in seconds (hard to see while inside vehicle)

When pinching the vacuum line to the fuel pressure regulator the pressure was a stable 45 psi, when released it returned to 38

After the car was turned off, the pressure remained at 38 for 15+ minutes.

The car was filled with 89 octane fuel and was approximately 75% full during the test

Have I properly tested my fuel pressure and FPR? What do these results indicate if they have been taken correctly? If they were not taken correctly, or I have missed something please let me know.

[thejlevie]

Idle pressure should be around 38psi and at higher engine speed it should be about 43psi.

[E30killer13]

It's probably the motor itself, mine is

1 140
2 139
3 145
4 145
5 120
6 140


mine also chokes when you blip the throttle and i think it's due to the weak cylinder.