Injector Pulse NOT corresponding the LOW Integrator and BLM?

A friend of mines 91 Grand Prix(3.1) has been running rich for some time now. Yesterday I took out my Snap-On Scanner to see if I could identify any problems. Everything looked OK, EXCEPT for one "strange" thing:

The Integrator and Block Learn values were low, but the Injector Pulse Width was not corresponding, and reading high!? For example, at one point, with the engine idling hot in Drive(700 RPMs), the Integrator was @ 108, the Block Learn @ 102, and the Injector Pulse was @ 2.1 ms? Why is the ECM not commanding a lower OPEN time for the Injectors? The O2 Sensor is working perfectly, and the ECM is responding, but it's not changing the Pulse Width for some reason?

My guess is there's something wrong with the MAP Sensor or sensor hose. This engine uses Speed Density to determine fuel delivery, but I'm not sure if the MAP Sensor is the KING of the sensors, and over-rides all others or not? Does the ECM "care more" about the MAP reading than the O2? Can anyone answer this for me?

I know MAP Sensors CAN go bad, rarely, but when they do, they usually read LOWER than normal, not HIGHER, I've never heard of a MAP Sensor going bad because of HIGHER readings!?

One other thing, what is the "normal" Injector Pulse Width for a Mult-Port Fuel Injected engine? I think it's around 1.3 ms, but not

100% sure.

Anyone have anything to add here? Should I look elsewhere, and forget about a fauly MAP? I truly appreciate all input!:)

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bigbossfan80
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