Hello Group........


I have a '93 Park Avenue Ultra with 164K. It is doing a lot of up an down shifting for no apparent reason related to driving or terain. Many times the "Service Engine Soon" light will come on and it will shift out of overdrive. When the light goes out, it will shift back into OD. Other times this up and down shifting happens without any warning lights coming on. Lately the "Service Engine Soon" light is on quitea bit of the time. I am not too knowledgable about these computerized vehicles. I am from the "old school". Could this be related to the failure of some kind of speed sensor? Any help will be greatly appreciated as the folks at the local Buick dealership do not seem to know anymore than I do. As evidenced by my last visit to them. They diagnosed the problem I was having as the catalytic converter when in fact, it was plugs and wires.

I would check to see if there is a TPS (Throttle Position Sensor). If there is, replace it and see what happens. I have had a similar issue with my '94 lesabre. TPS fixed that problem. If it does persist, then look at the Mass Air Sensor.

Thanks for your reply to my question. I will check into the TPS. Did you also have the "Service Engine Soon" light on?

Yes I had that as well. I still have it on, but the issue is resolved. As of now I cannot run the codes for some reason and will have to bite teh perverbial bullet and take it to a dealer. Even the local parts store could not use their scan tool. Just would not work.


Anyway, before you do start replacing other sensors (which will get costly)after the TPS, take it to the local parts store and see if they can run codes for you. They usually do it for free and you can get a better idea of any other potential issues.

hi, i have sort of the same problem, I have a 1993 buick lesabre. My "service engine soon" light is on..sometimes it goes on and off. My car starts right up..but sometimes it takes a few cranks. The car will also stall a few times while not moving or while idoling. The car runs fine, no problem accelerating, but just stalls sometimes while sitting at a red light, or will start and stall. Im thinking maybe the TPS, but im not a mechanic. Can someone please help me. I love buicks, but this problem i dont want to get to serious. car has only 122k miles on it, rebuilt tranny. when started it doesnt run at high rpms just stalls and i want to know what the problem is.

thanks for any advice
matt

One thingis sure, I don't get in any hurrysmileys/smiley2.gif. Today I finally went and bought a new TPS and installed it. I noticed that the one I removed did not have slotted holes, no adjustment. The new one does. I do not haveany info on theadjustment procedure or readings to do the final setup. The book I have only tells me to take it to a shop. It can't be that difficult. Seems that a digital volt meter should be the only necessary equipment. Can someone help me with this missing info?


Thanks