92 Sedan DeVille will not shift

Most gm cars for that year have the fuel filter located under the car on the passenger side just about midway or a little aft the front passenger wheel . You cannot see it unless the car is on a lift or you can crawl under. It is an in line canister shaped filter that is secured with a band type bracket. each end has a nipple that you slide the gas lines over and plastic locking clips that should come with the filter.

its very possible ,that's where tranny gets info to shift all your main gear shifting should be done by 35 mph and after 55 is overdrive the other is if you take it for a drive and manualy shift it out from lowest gear to highest and see how it functions, so you can feel the shifting advance then try it again just in drive only and see if you can feel the gears shift out , have you serviced tranny ? is it a high millage car it is 23 years old ,

Replace the gas filter!

That could even explain the failure to shift into Overdrive, as the engine cannot be running lean for the computer to allow it to shift into Overdrive.

Easy $10 fixya.

I have a 92 Crown Vic first and second works fine reverse works fine when it shifts in the third gear it goes to slipping and overdraft can you help me fix this problem thank you

At the very least you have a 3 speed transmission with overdrive, maybe even more gears. Assuming it is an automatic.
It should shift twice then go into lock-up before shifting into overdrive.
You would feel four shifts under normal conditions.
As far as not shifting, the problem could be electrical or something inside the transmission.
And the check engine light should be on.

check dash fuse

This sound like you are feeling the transmissions torque converter going in and out of lock up. When the torque converter goes into lock up it feels like a shift . One way to tell if it is the converter you are feeling is to push the od button disabling overdrive and see if it still does it. The converter will still go into lock up .

lost my overdrive,car runs fine,wont shift after it gets up to 35-40mph in drive,to drive it i have to use l1,l2,etc.where are relys located or solinoids?

overdrive may be worn out and u dont feel it shift or ur tranny is messed up

tcm/ecm malfunction