Could have been a loose or dirty connector, with that I would have thought you would have a code. If it wasn't reading MAF sensor, it was in closed loop fuel mode, and that would cause your issue. Glad it's fixed.

 

My daughter came by last night to get her car and return my truck, and she called me when she got home and stated it wouldn't go above 30.

I'm getting it again this AM to check it out again.

I. Just. Don't. Get. It. Quite frustrating.

Thanks in advance again!

 

This has to be fuel related.

 

I can check the fuel rail pressures, but it might be the injectors, whatever tells the injectors the amount of fuel to inject? ECM maybe?

First thing I'm going to do when I get it this AM is to check all the chassis/engine grounds as well as the connectors to the computer module.

I found a used one out of a '97 Lumina 3.1 for $35 here locally, I think I'll give that gamble a try.

 

It's not electronic IMO.

 

TPS might be worth a test too.

I drove it back, it got to street speeds and highway, but it did hesitate a few times fairly consistently. Example: when I was pushing the pedal to accelerate to 60 lets say, she went to the 3-040 range as expected, then the engine "pulled back" or went "flat" and stopped acceleration, but if I kept the pedal position constant during the event, in about three seconds, the engine picks up speed and shifts as expected, as if whatever is causing the loss of power is turned off.

I'm going to clean and reset all of the engine grounds that I can find, check the connections to the ECM, and even swap it out and keep testing her between these steps. I also grabbed a TPS and will replace the existing one if the previous two don't change anything.

Thanks for all the thoughts or assistance!

 

I did get a Foxwell NT301 and saved some running data, can I send it or upload it somehow?

BTW, I hope the Foxwell is an OK unit to do this, or is there a better one?

 

Here's an example of one of the "printable" moments that the Foxwell recorded, there are well over 50 pages:
Calculated Load Value(%)14.9
Engine Coolant Temperature(øC)93
Short Term Fuel Trim -Bank 1(%)-6.3
Long Term Fuel Trim - Bank 1(%)-2.3
Intake Manifold Absolute Pressure(kPa)71.0
Engine RPM(rpm) 1893
Vehicle Speed Sensor(km/h)20
Ignition Timing Advanece for #1 Cylinder(ø)-1.5 Intake Air Temperature(øC)51
Air Flow Rate from Mass Air Flow Sensor(g/s)36.42 Absolute Throttle Position(%)43.9
Location of Oxygen SensorsB1S12--B2S----
Oxygen Sensor Output Voltage Bank 1-Sensor 1(V)0.045 Short Term Fuel Trim Bank 1-Sensor 1(%)-3.9
Oxygen Sensor Output Voltage Bank 1-Sensor 2(V)0.105 Short Term Fuel Trim Bank 1-Sensor 2(%)N/A
OBD requirements to which vehicle is designedOBDII

 

Just test drove her again and got the error code:
PO102
Mass of Volume Air Flow A
Circuit Low

I replaced the MAF a few days ago. So I remeoved the new plastic one and replaced it with the original aluminum one (that's clean as a whistle) and there was no change in the error code. Plus, I then tested it with my multi-meter, here are the results:
1) With the harness disconnected and the engine/ignition off:
All three wires (red, black and yellow) ohm-ed out as ground.
2) With the key in the ignition and it turned to run position without the engine on:
The power wire (red) had almost 13 volts, the ground (black) wire was grounded, and the signal wire had about 6 volts.
3) With the engine running and the harness attached:
I tested the Hertz with my TEST BENCH set to 20 Hertz and the signal wire (yellow) had a fairly consistent 2.14 hertz at idle (engine warm) and when the engine revved it smoothly went to just above 14 hertz and then evenly went back down to 2.14 when the idle was slowly released.

So it seems the original MAF is working within specifications?
If so, why the code? ...and, more importantly, the problem in accelerating?

 

To add to my complex testing, I ran the car with my Foxwell attached and the Foxwell has a (g/s) reading for the MAF during the events in real time. It seems it was registering 4-5 during idle and was at the 40-50 range when it was bogging down, but when it cleared and accelerated as expected, it was well into the high 60s and into the 70s. Is this something that assists? Both the original GM MAF and the new replacement AC Delco MAF are performing the exact same way.