[ruckdork]

I had a 95 manual Escort that got 28-30 mpg in the city. The body got so rusted, I gave up and offed the car.
This summer I bought a 98 automatic with 110 k miles. The car body is in very good condition, and ran ok. But the gas mileage was terrible 20-23 mpg ?? actual.
So I started out with a normal tune-up
plugs- looked ok
wires- looked ok
air filter- dirty
oil & filter
pvc and hose- bad
timing belt and water pump (pm)
serpentine belt.
The car still idled a little ruff and still got poor gas mileage. So I had the car tested for error codes. Only had one error. (rear 02 probe short circuit) some one patched the exhaust half assed, cut the rear o2 probe and spliced in a pipe . Thinking this was the problem why the car was getting poor gas mileage. I replaced the whole exhaust system from the manifold back. And put on a new o2 probe. After all this, I am still getting 20-23 mpg?? Any ideas?? The other day, I checked it, and 20.9 mpg ?? !!
btw. tires are inflated and brakes are not hanging up. I read that tip from another post, lol.
peace

 

[FordMan59]

Might try cleaning the MAF sensor. Could also be the pre cat 02 sensor going bad. The post cat 02 sensor doesn't have any control over the A/F ratio's, that's left to the pre converter 02 sensor. Even if the plugs and wires looked good one of them could be bad. I would start by replacing the plugs and if that didn't do it then I'd move on to the wires. Is the car coming up to full operating temperature? It will run in open loop and suck the gas if not.

 

[madmatt2024]

If the plugs are original then you should replace them. If they aren't gaped right then you will get bad mileage.

 

[ruckdork]

Everything I listed above I changed out. I was just saying that the old plugs and wires looked ok. (my bad)

I did remove and spray clean the MAF sensor.

You mention the pre converter o2 sensor could be bad. If so, wouldn’t that have given me an error code?
I also used a couple bottles of injector cleaner, because the gas filter was nasty! Like mud coming out of it. I think it was original.

Thx for the input!!

 

[madmatt2024]

The O2 sensor has to get really bad before it will trigger an error code.

 

[Coda1]

I am having the same problem. I had a 95 and got good mileage and now have a 99 and I can't get anywhere close to what I used to. I have already replace the O2 sensor along with the plugs, wires, and PCV valve. I just bought a can of mass air flow sensor cleaning and am going to try that next and look for any vacuum leaks. I know they can do better I just need to figure out what is wrong.

 

[ruckdork]

Well I filled up the car today with 7.2 gallons on 146 miles. 20.2 mpg, this sucks....... 40 of those miles were on the highway and the others, I drove like a grandma.
I also change the other o2 sensor like recommended. I am running out of ideas. I am tired of sinking money into this car trying to improve fuel economy.
Mean while my wife’s Honda civic get 28 in the city, and 42 on the highway (no chit).
This car is gone come spring time. I might as well drive my Tahoe.

If anyone else can throw some ideas this way, I appreciate it. I have been all over this site reading posts.

Thanks again. Peace

 

[PonyExpress]

try changing out the trans fluid and filter. old hydraulic fluid in the transaxle can cause this as well.

 

[ethangsmith]

INTAKE VACUUM LEAK. Replace your intake gaskets, check all the vacuum lines, especially the one under the throttle body, check that the brake booster is not leaking vacuum, and also remove, clean, and check the EGR valve.

 

[ruckdork]

Thanks ethangsmith,
I am good with most repairs, but not with trouble shooting. I was thinking at the point I am at now, I just going to have to pay someone to find the problem.
I will start by having them check out the items you mention. Thanks.

I can't wait until spring, and ride my Honda Ruckus scooter to work again. I get 100 mpg on it (love it) It's cheap transportation.
No insurance
$15 for three yr registration
No motorcycle license
No helmet (if I want)
We had a scooter trend going at work. There was 8 grown men riding scooters to work summer of 08. Down to 4 this past summer. I need to post a picture, funny chit.
That's where my user name came from, Rorkdork. My 11 yr old said I look like a dork on it. (lol). I will repay him someday for talking chit, lol. maybe I will save him the Escort when he gets old enough.

Merry Christmas, Peace.