95' Corolla, questions regarding gas mileage

[Blek]

Hi all, I'm pretty new here and really new to corollas and working on cars in general.

I'm trying to help out my moms car which she was complaining was only getting bad mileage. I took it out and tested it and it seems to be only getting 19 mpg. Which is worse than my truck 0.o It is a 95' Corolla with a 1.8 litre engine and 100,000 miles. I checked the air filter and it was filthy and full of sand so I vacuumed it out and replaced the air filter and replaced all the spark plugs which were also nasty. That helped a little but not as much as I would like.

Do you all have any suggestions to get the fuel mileage better? I assume a Corolla should be getting much better than this.


Also I was wondering what type of motor oil you would suggest for this car. It is in an extremly hot environment in arizona. Being 105-120 this summer. She also has a long drive to Utah this month I'de like to make sure she is ready for. ARe those high mileage motor oils just a gimmick or are they worth it?

Thanks in advance.

[sonyminidiscman]

i use synthetic oil...... good ones...

makes it run smoother... I am not sure if u know how to conver,

I am getting 8.5L/100km if I drive conservatively...

it goes up to 12L/100km for track day

[hdsalinas]

I have a 99 with 100k miles on it and I get a similar mileage. I am going to have the injectors cleaned soon and if that does not help I might have to replace the O2 sensors.

I am actually thinking to get rid of the cat converter and see if that helps a little. (I am in Honduras) As you can see I am a bit desperate. I have replaced a bunch of stuff (sparkplugs, cables, PCV valve, among others) and i still get the same mileage.

If you ever fix the problem, please let me know.

[Chris Corolla S]

It sounds like the car has not been taken care of if the airfilter was dirty and the plugs were fouled. Fouled plugs usually point to some other problem. What did the plugs look like? black? burnt? corroded?
It sounds like it is time for the full 100,000 mile service. You can't neglect basic maintenance and expect good performance.

I suggest Mobile One synthetic, but if you have been running regular oil, I would not switch over at such high mileage.

[Blek]

Thanks for replies. Well I have no idea what Oil she was using before I moved back here. She didn't change it enough I know that. The sparkplugs had alot of buildup crap on them was hard to see all of the prong on 1.

[Aktunka]

Also, on the air filter, don't skimp by trying to vaccum out and reuse an old dirty one. Just spend the extra few bucks and replace it to do it right. I would echo what others said though and take that thing in for a checkup. Sometimes a relatively tiny problem like a sensor or something could really screw with mileage. Couldn't hurt to have them check the exhaust system as well since a clogged cat converter sure wouldn't help matters any. Also, all of those little things will help. Proper tire pressure, making sure the brakes aren't sticking, etc etc. Good luck.

[hdsalinas]

I have been checking my mileage lately and it seems to have dropped to a pathetic 17mpg (city).

I made a list of things that I have been observing that may have something to do. They are connected to the emissions system and may give me some clue.

Besides de excessive fuel consumption, I have been observing the following: remember that this car has 100k miles.

1) When you turn the key it takes a second longer than what you would expect for the car to start.

2) When idling and you are outside the car there seems to be a strong "burnt gas" smell. (Like if it was burning too much gas)

3) I have observed that the car may use up to a quart of oil between oil changes. (At last oil change I switched to Pennzoil high mileage oil)

Besides this, the car runs smooth. Acceleration seems fine. The car never sputters or stalls. (Although it seems to lag sometimes while flooring it. I was used to a 4.3 V6 so this might just be
Normal for this engine)

I am planning on performing this "tune up" to the car soon:

1. Clean injectors (never done before AFAIK)
2. Change air filter (last change was performed almost 10k Miles ago)
3. Check and gap sparkplugs. (Also less than 10k miles old but were never gapped)
4. Replace oxygen sensor (main one)
5. Check PCV (changed 5k miles ago)
6. Check computer for codes

What else could I check?

I feel that the o2 sensor may be the culprit. I read on the Haynes manual that if I were to disconnect the oxygen sensor the computer would use the default air/fuel mixture. I could try that and see if I see a difference. That way I don’t change it if I don’t have to.


I appreciatte your help.

[bjaques1]

someone please help me!!?? My 95 corolla, 1.8 is jumping and jerking.I have replaced plugs, wires,fuel filter,dist. button,and don't know what else to do. Sometimes it even acts like it wants to stall, but doesn't. Any idea's???? I'll try anything at this point. what about the EGR modulator valve??

[rlld23]

Sounds like all of you have the same problem I do. I fixed timing belt and new plugs, valve seals and adjustment, and the whole tune up. It still gets me 18 miles per gallon on my 93 tercel. I checked my all my plugs and they all get really wet from gas. All 4 injectors are good and the timing is set.

The next step that nobody thinks about is the FUEL PRESSURE REGULATOR.
If it goes bad it can cause less gas to go to the injectors or way too much gas to go to the injectors. I think This is your guys problem here. So no matter how good a tune up you do, if you don't fix this, it will use gas like crazy. Remember toyota tercels and corollas should get between 30 and 40 miles per gallon not between 10 and 20.

The O2 sensor could cause your car to use more gas but nothing like 18 miles per gallon. Thats insane. Maybe more like 27 or so.

For the guy with a new corolla and bad gas mileage and the funny egg smell. Thats the first sign that your catalytic converter is bad. How it get this way with it being so new? who knows but it needs to be looked at.

For the guy with a jumpy motor you need to check to make sure that each spark plug wire is getting juice to spark plug. Pull spark plug out and see if it gets spark when the engine is turned over. Ifit does then check your fuel injectors and see if they are plugged.