'90 323 Bad Gas Mileage...

[crazyrog17]

My girlfriend's 1990 Mazda 323 Hatchback (1.6L SOHC Auto) gets pretty bad gas mileage. Last night we drove 4 miles to WalMart and I saw the gas gauge go down about 1/8 of an inch that trip alone. Could be a shoddy fuel level read out, I don't know..

When I let off the gas to coast, the car rapidly decelerates probably 2mph/second. I know my '93 Grand Marquis is a giant boat, but you can't even tell I let off the gas when I coast.

I know for sure it's not the emergency brake dragging, or any of the brakes dragging for that matter.

Could it be wheel bearings? I don't know. The auto tranny?

Any insight is appreciated.

[Roboskittle]

Automatics arent known for their coasting ability. The decel much faster than say a 5spd car that you put in neutral. Wheel bearings could most certainly be causing your issue along with a number of other things. What are the tire pressures at vs what is the max on the tire? If I have a tire that maxes out at say 45 psi I usually put 40 in them. I would suggest you check out your wheel bearings. The back ones are easy to do just jack the car up and spin the tire. If it stops short of a full rotation you know you have issues. Should take very minimal effort to spin the wheel. Have you actually calculated your MPG?

[crazyrog17]

The tires are 10 years old, really really need to get some new ones on there before I go fillin them up with 45 psi, but I set them at 37 (tire does say 45 max) for now.

I'll do the rear wheel test when I get a chance.

I'm going to do a legit calculation today. Fill it up, reset trip odometer, drive it till it's nearly empty, fill it up and calculate miles driven/gallons consumed.

[pwgus]

I used to do this with my 3 speed auto, see if it helps, when coasting, shift into neautral. Altho I think the 323s are 4spd so I wouldn't think it would be so bad with the od.

[crazyrog17]

I used to do this with my 3 speed auto, see if it helps, when coasting, shift into neautral. Altho I think the 323s are 4spd so I wouldn't think it would be so bad with the od.

Yeah, it's a four speed auto. I put a few pounds more air in the front tires (they were still sagging at 32 psi) and can definitely tell a difference.

The neutral shift sounds like a great idea, but the shift selector is wonky as can be and I'd rather just leave it in gear. Thanks for the idea though.

I think my next order of business is lifting the car up to test the bearings.

It's going to the Mazda dealership tomorrow to get the passive seatbelt track replaced.

[miami man]

my mom has the same type car and after tune up it still eats up the gas. with air conditioning and auto and the weight of the car it does not accelerate like my other cars even my 99 saturn.

[crazyrog17]

Alright, so in painting the wheels, I jacked the back left wheel off the ground, took off the parking brake and tried to spin it. It gives me a lot of resistance and won't spin on momentum only.

What can I do now?

[bhazard]

Its either the brakes dragging or bad bearing.

[crazyrog17]

Yeah, the passenger side rear wheel spun for a minute after I whipped it around.

Messing with the e-brake cable/arm on the back of the drum got it to spin a LITTLE bit better...

Is the star just too tight, or what? I'm going to put new pads and shoes on it soon. I guess I'll just have to see how it spins without the drum on to know how the bearing is doin.

[crazyrog17]

Alright, just to cap this up...

I read on clubprotege.com that there seems to be a widespread problem with the emergency brake return springs on the drum assemblies of the rear wheels. The spring isn't strong enough to pull the cable back when everything gets rusty and it makes the shoes drag. That on top of the worst designed brake adjusters I've seen yet make a winning combo for draging brakes and terrible gas mileage.

Anyways, I resolved it by doing the rear brakes by changing both shoes and hardware. I cleaned and straightened out everything I could, and the car drives very well now. The acceleration still sucks, but it's an automatic with ~85 hp...