bad gas mileage with my 4 cyl camry--l@@K

[excoupe23]

My father just gave me his 93 camry 4cyl and it is a good car with only 99k original miles. I am getting bad gas mileage, averaging 17mpg mixed city and highway driving. My question is what if anything is being overlooked by me to increase my mileage because the list goes on and on with the things I changed already. I used to have a 92 camry 4cyl years ago and that sucked gas as well. Is it just that toyota's burn fuel more often that other cars in it's class. I owned two accords and I would get at least 330miles off 13 gallons of fuel opposed to now 270miles on 15.5 gallons fuel tank. Any help will be appreciated

I changed the oil and filter 1k ago with castrol gtx
32psi tire pressure checked on factory rims
new fuel cap--ran two bottles of fuel injector cleaner
no check engine light ever came on with this car and I checked for codes just to be sure
flushed auto transmission fluid
motor runs well, no burning of oil at all, no overheating, good compression.
changed wires with ngk wires, ngk iridium plugs(not cheap), new cap, rotor, new distributor, no misfiring at all and car has good accelaration. I love the car with no complaints but the gas mileage is horrible.
--done the ignition timing to specs according to haynes manual
new k&n drop in high flow air filter
cleaned intake manifold with seafoam, cleaned throttle body and iacv.
--new o2 sensor 1k ago

Is this the best mileage I am going to get because it is discouraging when I put my own effort to change things thinking it will help my car and it doesn't make a difference in gas mileage. I also drive moderate without flooring it.

[InstallTech]

Wish I knew how to help here. I get about 350-400 miles on a full tank with my 93 4cyl 5s-fe. Fuel filter maybe?

[Brian R.]

Did your father also get such bad mileage when he drove it?

Check the ECT sensor.

[Mike Gerber]

I agree with Brian about checking the ECT (engine coolant temperature) sensor. It may be faulty and telling the ECU (computer) that the car is always cold. This would result in the fuel mixture always being too rich and using excess fuel. This type of problem does not always throw a check engine light.

Another thing that could effect gas mileage is the thermostat. If it is stuck open, it will lead to long engine warmup times, also resulting in the engine burning a richer than normal fuel mixture during that extended warmup period. Does the car heat up quickly and give good (hot) heat during the cold weather?

The third thing that comes to mind is a dragging brake. With the car in neutral and the emergency brake off, jack up the car at each wheel and spin the wheel. Does each wheel spin freely? If one wheel does not, that brake may be dragging. This will greatly effect fuel mileage. If you find a dragging brake problem, repair the offending brake.

Mike

[excoupe23]

tell you the truth my father got great mileage from the car. Even when I drove this car from Va to NY. I got 385 miles on a tank highway. In a way I thought it was the gas because in Ny there is a winter blend where 10% of the fuel is ethanol alcohol and in Fl that is not used but I do not think that alone would cause the problem. You guys did give me some things to look into because
1--I will look into changing the ect sensor but is that only a dealer item and how much does it cost.
2--My thermostat is fine, the car warms up quickly and the car gives good heat.

[Mike Gerber]

You can get an aftermarket ECT sensor. It should run about $40. You don't necessarily have to change it out. You can check it first. You will need a DVM (digital volt/ohmeter) and the specs from a manual. The generation 3 manual at the top of this forum will have it.

Mike

[excoupe23]

thanks for your help. You gave me some things to look into. I heard about brakes dragging but what can cause that. Is it a sticking caliper or something to do with new brake pads grabbing on the rotor.

[Mike Gerber]

Dragging brakes can be caused by a number of things. The piston can seize in the caliper (or rear wheel cylinder for rear drum brakes), preventing the caliper (or rear wheel cylinder) from releasing after the brakes have been applied. This is usually caused by water making it's way past the seal and causing the piston to rust in the caliper bore. If this is the problem the offending caliper or wheel cylinder needs to be replaced or rebuilt.

The slide pins can seize in the caliper, again preventing the caliper from retracking from the rotor after the brakes have been applied. This is usually caused by water making it's way past the accordian shaped boot that covers the slide pins and again causing some rust. If this is the case, sometimes you can remove the slide pin(s), clean it up a bit with sand paper, and relube it with high temperature disc brake grease, and reinsert it in to the mounting bracket. Sometimes the pins are very difficult to remove from the caliper mounting bracket and get scored and must be replaced when you get it out. In addition, the rubber accordian boot sometimes has to be replaced as it sometimes gets ripped in trying to remove a stubborn slide pin. Also the hole they go into in the caliper mounting bracket must be cleaned up too. Sandpaper wrapped around a pencil or drill bit can be used for this, but a sand blaster or a bead blaster is best. Then blow out the cleaned hole with compressed air, and then put some high temperature lube down in the hole, and then reinsert the lubed up slide pin. Make sure you can move the pin freely in and out slightly once it is reinserted in to the caliper mounting bracket.

Sometimes an emergency brake cable can rust inside it's sheath and keep the emergency brake applied to one or both of the rear brakes. If this is the case, the cable and sheath combination must be replaced.

Sometimes a rubber brake hose can collapse, preventing the brake fluid from returning to the brake master cylinder once the brakes have been applied and released. If this is the case, the offending hose must be replaced and the brakes must be bled to remove the air that has entered the system when the hose was removed. This failure isn't quite as common as the previous three.

These are the most common things that can cause brake dragging.

Mike

[excoupe23]

that helped alot. I will check it out soon.