About three months ago I purchased a 1991 4 cyl (auto) Camry (94 K). The gas milage at that time was 34 mpg. I began to notice that my milage was getting worse with every fill up. Now I am getting 24 mpg and am driving the same routes to and from work. Any ideas. Is there any chance that the dealer could have done something short term to make it better?

Thanks,

I do not know under what conditions you bought your car, but I would start with regular maintenance: spark plugs, ignition wires, distributor cap.
For the car that age a little Seafoam will make a big difference.

Sam

I'm assuming nothing has changed on your route like more stop lights etc. Semy... made a good point. Beyond that, with 94K miles on it it's time to change the timing belt unless the dealer you bought it from can confirm it was recently changed. It may have slipped and thrown the timing off. A quick thing you can check is make sure the distributor is tight and won't twist. That will also throw the timing off. Retarded timing will decrease your mileage in a heartbeat. Get a timing light and check the static timing . Should be about 10 Deg BTDC on a 3S-FE 4 cyl. (your timing setting should be printed on the emissions sticker under the hood) If you're getting gas from the same station all the time, try a different station.

I've changed the timing belt twice on my 87 with the 3S-FE 4cyl with 270K on it. I'm getting 30-31 MPG. If you've got tools and are motivated you can change the belt in a day. If not it will cost $2-300. Belts are about $20. Let us know what you find

RIP: What special tools do I need to change timing belt? For Camry 93 (5SFE) thanks.

First, if you don't have one buy a maintenance manual specific to your year.

Tools: Jackstands (be safe)
Bottlejack - need to detach the left motor mount and raise the engine to get the belt out (any small jack will do)
Large prybar - to get the crank pully nut off
Metric socket set

The first time I changed it I couldn't get the crank pulley nut off with the prybar screw driver combo (see your book). Had to borrow an air gun. It spun it right off.

Was your timing off or are you changing it due to mileage? Keep in touch.