I have a 94 Bonneville with plain 3.8. I am having trouble with changing gears or something. When you go to kick it down to pass someone it will not kick down. It just gradually takes off. Advance said the throttle position sensor reading was high. Put new one on and still had the check engine light and the same problem. Took the car back for them to clear the codes and it would not clear. They would try to clear and as soon as it did it would pop right back on. So he checked it again and it said throttle sensor signal low. So I said what are the chances that the new one is bad. They said unlikley. I had them change it out anyways and still the same problems. So I put a new modulator valve on thinking that would have something to do with it shifting but no change. It shifts good when you pull out to get going but when you try to kick it down nothing happens.
Does anyone have any ideas on what to check next? Please reply soon. Changed fuel filter, plugs and wires about 3 months ago.

Maybe some tranny problems, overdrive gear not engaging? It should engage when you throw the pedal fast into half throttle if speeds under 35mph and if you're going faster than that you should slam the pedal down all the way. It mentions it in your manual.

Hi.. welcome to the club.

Do you have the actual code numbers that they pulled each time? Many times the parts puppies will tell you it has to do with and sell a part. IIRC the 94 was not an adjustable TPS, it is in a tough place to change though. Try and ensure it is mounted properly with both screws holding it.

Others should come up with more soon.

I'd like to know what voltages they had each time. We kinda need to know that before going any further with regards to the TPS.

Does cruise control work? Does OD work at 48mph?

I will try and do the voltage today. I had not thought to check the cruise control. When they first pulled the code it was P0123 and then they pulled the code with the new one installed and it was P0122. I had them to exchange the TPS for another one but the problem is the same. I drive the car in overdrive all the time. If the trans was going out would it still drive in overdrive? It still drives good and everything and I still get at least 25 to 28 miles per gallon. It just will not kick down going up hills or when you go to pass someone.

Is there a way for me to pull the codes on this model? My plug does not have A nd B together on it.

No, you cannot pull codes on your 94 without a scantool.

See if cruise works. We need to know that. Check your TPS voltage at idle (car not running, ignition on), and WOT (again, engine not running but ignition on).

The TPS is a big player in CC and OD. I'd suspect if your TPS was reading too high, CC and OD wouldn't work or would be very touchy and sensitive.

Just went for a ride and the cruise control seemed like it wanted to work at 45 or above. But then it didn`t. So I guess it really was not working right. May I ask how to check the voltage? Will a regular checker work?

You are now at the same point as another member here. A digital or analog voltmeter will work, but a scantool is preferred.

I STRONGLY suggest you buy Chilton'* #28200. This manual is the bare minimum that each member here should have on the toolbox. It clearly describes the TPS circuit and how to check it. Not to mention minimum and maximum values for the TPS.

This manual is invaluable for 95% of the work you may need to do to the car, and should cost under $20. It'll pay for itself very quickly.

You may outgrow it at some point and want to upgrade to a set of Factory Service Manuals (about 50-100 bucks depending on whether you get them on eBay or new).

If you can afford it, get that Chilton'* ASAP. You won't regret it. The TPS issue will be cake at that point. Use paper bookmarks and make notes. WRITE in that book as you work. Your notes and observations as you do the work could prove valuable to someone here.

Thank you for the great advice. Should Autozone or Advance have this book you are referring to or where can I get it?