WTF....11mpgs in city but 18 on e-way?

[backfrmcolorado]

Ok...well my 94 x just seems to be getting worse on gas. Im getting anywhere from 10-12.5 mpgs around town. When i first got the truck 6yrs ago i had no problem getting 14-16 in city driving with my lead foot. Now getting older my driving habits have changed. When i drive i normaly dont let the tach get above 2100 rpms. Its not makeing much sense. Truck gets regular oil changes at 2500-3000 miles and just recently did a tune up ( plugs, wires, coil pack, air filter) no change. Replaced fuel filter and paid to get injectors cleaned at dealer. Still no change...im a wits end on this. I drive 45 miles a day round trip to work. Its getting expensive!.

Can anyone help me out here....id really really apreciate it. Thanks!

 

[Glen4X4]

Is your truck auto or manual? When I had a manual Ex I shifted at 1500 rpm. You also have to realize the truck is getting older so the sensors could be starting to give false readings also.

 

[Jason94sport]

Some new 02 sensors may do it. They wear out. They do not trip codes. Maybe time for a new cat as well.

 

[Marv]

I have three older vehicles and one of them is a 94 Explorer.
All three in the past couple years has decreased in gas mileage.
It started off one week good gas mileage then next week poor gas mileage
One common element is the 10% alcohol in the fuel.
Depending on where I bought fuel, some had alcohol and some were alcohol free.
Now all fuel in my area has 10% alcohol and all three cars has lost about 5 mpg.
It may be nothing wrong with your engine other than the fuel you feed it.
Marv

 

[ppbskis]

I have owned my 92 4dr XLT for 4 months now. I was getting great mileage 21 highway for the first 3 months and going home one night my Check Engine Light came on. The fault codes indicated a bad Oxygen Sensor. so I replaced the sensor to no avail still had the CEL. Unfortunately I had to find a new mechanic do to a job reassignment and he has since diagnosed my problem as a bad intake gasket. My mileage ranges from 12 to 15 mpg, I can't wait to get it fixed, unfortunately he is quoting me a $ 750.00 repair bill.

 

[Tony H]

I have owned my 92 4dr XLT for 4 months now. I was getting great mileage 21 highway for the first 3 months and going home one night my Check Engine Light came on. The fault codes indicated a bad Oxygen Sensor. so I replaced the sensor to no avail still had the CEL. Unfortunately I had to find a new mechanic do to a job reassignment and he has since diagnosed my problem as a bad intake gasket. My mileage ranges from 12 to 15 mpg, I can't wait to get it fixed, unfortunately he is quoting me a $ 750.00 repair bill.

Whe I first got my 'X' the intake gasket started weeping antifreeze. It had 183K miles on it..
Changing it looked scary. Too much disassembly.. After the dealer quoted me $1500. I did it myself. I took Pics and marked all the electrical connections.
These engines are stupid where you have to take the Valve covers off to do the gasket. The intake gasket is part of the valve cover gasket.

 

[LXNavajo_94]

Intake gaskets arent hard I did mine in an afternoon after mine went from a slight weep of coolant to a gusher. Took me about 5 hours. I think all in all the 2 gasket sets were 75.00 total and injector orings were maybe 3.50 or so. There are some good writeups on that subject around here.

As far as gas mileage being way off I recently went through that myself tune up new wires and autolite double platinums helped. Replaced the DPFE sensor and TPS both codes were showing but only the TPS was tripping the CEL after replacing the camshaft position sensor which I broke either while changing the transmission out earlier this year or when changing intake manifold gaskets not sure it could have been both. Then still had what I thought was a miss under load on the highway. The coil pack checked good Turns out the VSS driven gear was shot replaced both the gear and vss and it now shifts into OD and torque converter lockup without hunting between gears at highway speeds. It would run fine up to third then skip between OD and TCC at will giving me the supposed miss.

 

[Tony H]

Yup.. one afternoon, 3 hours for me. You do not need to 'break the upper manifold section from the lower so the Injectors can stay installed. Same with Fuel and acceleartor cables. After you get down that far...Just unbolt and roll it up and out of the way. It will basically lay upside down by your Brake booster

 

[LXNavajo_94]

My injectors were pretty carboned up. I guess from where the modulator was leaking trans fluid from when my mom had it. I asked her when I got it from her was there anything I needed to know and she said it loses about a quart of trans fluid a week and blows these hoses off every once and a while she pointed to the vaccum tree lol. She said it had been doing that for about a year and a half. She was driving 50 miles a day round trip at the time. Thats what led me here in the first place.I have seafoamed it several times but between the trans fluid and gasket leak I guess it didn't ever quite get em clean.

 

[colintrax]

Ok.... When i drive i normaly dont let the tach get above 2100 rpms.

You need to accelerate faster for one. You aren't getting to the fuel efficient gears fast enough by accelerating that slow. If your driving habits have changed, are you braking more? Taking corners slower? Less likely to run red lights? Slow down/stop more for stop signs?
Everyone thinks that driving like a grandma ups gas mileage, in reality it doesn't. Other than not going 90 mph down the freeway.
Also remember that your truck is getting older, so parts aren't moving as easily, your compression is lower, the ports (intake and exhaust) are probably filled with carbon, tranny isn't shifting as fast, sensors are less accurate, ect ect.
Lastly, have you added anything? Big tires? System? Everything adds weight, which makes gas mileage go down.

 

[backfrmcolorado]

Lol well i think almost every comment has summed it up. It is an auto...the o2 sensors are shot. (cel light is burned out. Took truck to autozone and the checkd it anyway). Upper intake has a small crack. Sso all new upper gaskets will be getting replaced. And when and if i take off above 2500ish rpms theres an even more drastic drop in mpgs. I have noticed in the past few days its been rainy and damp outside....my right rear brake is hanging up. Thinking thats another factor.

 

[The Yellow One]

Well I just bought a 92 and thought I was doing decent with 17 mpg on longer trips. Guess I should be getting 20-22 maybe? I to try to take off easy and drive easier than I have in the past. In the near future I plan on doing a service and change filters and such.

 

[backfrmcolorado]

Yeah i actualy just got another x a 92 as well. It has a 4in lift n 31 inch tires. Im courious to know the difference in mpgs after i start driving it n get it plated n insured.

 

[huntman58]

Well I just bought a 92 and thought I was doing decent with 17 mpg on longer trips. Guess I should be getting 20-22 maybe? I to try to take off easy and drive easier than I have in the past. In the near future I plan on doing a service and change filters and such.

so for having 230,000 plus and 31's on it and a heavy front brush guard with 3.73 gears and I get 17 MPG all day long on the open road as long as I do 55 to 65 I guess I am doing okay then but around town dang talk about a thirsty mother. but then to it is a box being shoved by a underpowered motor by today’s standards but then to it was not built as a high MPG auto from the start but as just what it is a SUV with more on Utility then as to day 's wee its more on sport.