Car: 89 Cutlass Supreme w/2.8L MPFI
>This morning I checked my Fuel Pressure with my NEW Gauge and got the
>following readings:
>
>KOEO: 42 psi
>Engine Running: 38 psi
>
>So, this figures seem to be almost perfect for my engine, right within >specs!
>
>BUT, I still have poor acceleration problems. Plus, I am running LEAN
>upon acceleration, but RICH at idle and deceleration!!??
>
>I've been borrowing a neigbours Snap-ON Scanner, plus I just installed
>an AutoMeter A/F Gauge this past Saturday.
>
>My "Block Learn" figures start good, but after the engine is HOT, and
>the engines been running for 30 minutes +, the BLM drops to "100",
>which on my ECM, is the minimum that it's calibrated for. It can go
>from 100-156, and my Integrator can go from 76-180.
>
>When I start to accelerate, especially hard, the Integrator jumps to
>above 160, and my O2 sticks LEAN for about 3-4 seconds.
>
>All my ignition components, coils, module, plugs, wires are New. O2
>sensor is New. EGR valve is New. Cat. Converter is New but will die if
>I don't fix this problem soon...
>
>I was hoping to find a Fuel Pressure problem, but I didn't. I know
>that a Fuel Pump is supposed to FLOW a certain amout of
>gasoline(gallons per hour), so maybe this could be a problem!??
Check fuel delivery (volume).
>Also, I was thinking it might by a STUCK Fuel Injector. Because it all
>makes sense: The engine goes Lean on acceleration because one of the
>Injectors is not responding to the command to open MORE, and it runs
>Rich when idling and decelerating because the bad Injector is not
>responding to the command to open LESS, right??
>
>Or, could I have a Vacuum Leak somewhere? This engine is Speed
>Density, so I'm not sure how it could be affected? I do have a Vacuum
>Gauge and I'm getting 17" at idle in Park, and 15" at idle in Drive
>with the brakes applied.
>
>Any EXPERTS here!??
>
>THANKS!:)
ANY vacuum leak will cause problems with a speed density system. Be especially careful to check for leaks in the intake hose and throttle body base.