I haven't check the TPS yet, but I did find a TSB on alldatadiy.com that describes the condition that i have and the fix is to test the TPS and replace it. Here are some details.

It sounds like it is difficult to check... I may just replace the TPS. I have the original sensor in the car.

-------------------------------------------------------------------------------------------------
Bulletin No.: 05-06-04-058

Date: September 07, 2005

TECHNICAL
Subject:
Intermittent Chuggle or Fishbite on Light Acceleration or at Highway Speeds with No Diagnostic Trouble Codes (DTCs) (Replace Throttle Position (TPS) Sensor)

Condition

Some customers may comment on an intermittent chuggle or fishbite on light acceleration or at steady-state highway speeds (typically 80-105 km/h [50-65 mph]) with no PCM DTCs set. This condition may lead the technician to suspect the TCC circuit or torque converter.

Cause

This condition may be caused by intermittent operation of the Throttle Position (TPS) Sensor.

Correction

In observed cases, the Tech 2(R) is not fast enough to consistently detect this condition during a snapshot. It is recommended to use a DVOM set to the min/max recording mode. Connect the DVOM at the TPS connector (positive lead to TPS feedback signal pin and negative lead to TPS ground pin). Duplicate this condition by driving the vehicle. If the voltage dropout (less than 0.45 v) is recorded on the DVOM, replace the TPS sensor and re-evaluate the vehicle before continuing with other driveability or transmission diagnosis.
-------------------------------------------------------------------------------------------------

Go back one page, I have a link to testing the TPS. It'* a 2 min job and only needs a multimeter.

Well, i guess i shouldn't have set difficult to test... More like difficult to catch since it is intermittent... I'll let you know how it goes.. too late to deal with tonight... it may be the weekend before i can get to it...

thanks for the help!

Ok, late night testing...

I went ahead and bought a new TPS earlier today just in case. So, i took the old one off and tested both.

Old TPS:
At the zero clock (initial position) the readings were a little erratic. I could actually just push down lightly on the armature and get the reading to change from 0.58 to 0.64 without any rotation. At the onset of rotation, the readings would actually initially drop just a tad and then start rising. The max rotation resistance was 5.0

New TPS:
Rock solid at the initial position (zero rotation) at 0.51, then 5.1 at the max.

The midpoint on both seemed to be at about 3.0.

So, anyway, i replaced with the new one and I'll test drive starting in the morning.

I'll post an update.

Thanks again! Hope this was the problem.

Sounds like that may be your problem. Hope the new TPS helps.

An update. The problem has not been fixed...

I'm clueless. Symptoms as described still occurring. Any ideas would be appreciated.

I keep getting Engine Coolant Temp engine codes also. Another piece of the puzzle.

Could you be so kind and give us a list of everything that you have done so far.

Ok, refresh of the run down of sensors replaced so far...

2002 Bonneville SE with 181k miles. I have replaced (in order):
new spark plug wires
rebuilt MAF sensor (had gotten a code on this)
new fuel filter
new Engine Coolant Temp sensor (had gotten a code on this)
new Fuel Pressure Regulator (pressure check in spec at key on and idle)
new Crank Position Sensor (AC Delco part)
new MAP Sensor (as of tonight)

I had found a post of someone with similar symptoms.

https://www.gmforum.com/t279080/

His problem was fixed with a new MAP. This is interesting. About a few weeks before my problems began, the coolant tubes (the plastic elbows that route through the belt tensioner) had failed and resulted in dexcool coolant being sprayed all over this sensor. I had replaced the elbows, flushed and filled the sytem with the green stuff. A little later, I started having these other problems. Now, I wonder if the coolant had caused this sensor to fail (I hope).

Anyway, I've now replaced the MAP sensor. I will keep you guys posted.

Another sensor that is right in that area and can cause problems very much like the crankshaft sensor is the cam sensor. If you sprayed coolant all over, you may have gotten the cam sensor.

Thanks Dan! I'll keep that in mind...

Frustrating.. Sometimes the car will drive fine for a day or two. So, it may take a few days to see if the problems has gone away. I'll post new info as I have it.