4.0l 4x4 crap MPG first time ford owner

[chazz79]

I have a 1994 stx extend cab 4x4 ranger 4.0l automatic on 31" tires with a 2" body lift.

I bought it a few months back and installed new heads, valve covers (things rot in ohio), mile marker hubs, plugs, wires, air filter, calipers, wheel bearings, front hoses and lines. Needless to say I had 2400.00 wrapped up into it before I figured out it would only deliver 11mpg

Yup 11mpg no matter what I do driving wise...I'm getting 200 miles out of a tank of gas.

Absolutely all repairs were handled in a professional mannor with the exception of gutting the cat. The cat gutting happened after I had heads on and found that it was likely the bright glowing red catalytic converter that popped the first set of head gaskets.

It took 17 years of driving before I ever owned a ford, I actually like the truck
and would love to keep it once I make driving it affordable.

 

[hondaxr650]

Did it have 31s on it from the factory? If not, your speedo/odometer may be completely innacurate and you may be getting a lot more miles out of a tank than you think you are.

 

[legoms013]

Put a new cat on it. Without the innards in the cat the computer is doing screwy things with the fuel.

My truck (when it was stock) a supercab 4.0L with 31's gave me a consistent 18 and high 19 mpg if I drove nice. That's with 3.73's.

With that truck you should be getting about 300 miles per tank and more so.

 

[alwaysFlOoReD]

It's obd1, the o2 sensor is before the cat and won't affect the computer. But it doesn't hurt to have the cat in once the engine is sorted out. Right now we need to know if there is any cel [check engine light] on? Any symptoms that would point us in the right direction for diagnosis? You may be getting less than optimal mileage because of tire size versus gearing and as hondaxr650 says you may be off in your figuring. I'm running an '85 b-II with a 4.0/5-spd/4.10 gears/31x8.50-15". my gps says I'm doing 100, my speedo says 94. I'm getting 18 mpg[us] city driving.
edit; reworked my #s and it's 18.2mpg[imp]=14.6mpg[us] city driving [delivering pizzas...so I'm not easy on it]

Richard

 

[Sasquatch_Ryda]

Put a new cat on it. Without the innards in the cat the computer is doing screwy things with the fuel.

My truck (when it was stock) a supercab 4.0L with 31's gave me a consistent 18 and high 19 mpg if I drove nice. That's with 3.73's.

With that truck you should be getting about 300 miles per tank and more so.

Not true...his truck has no way of knowing what the cat is doing. It is OBDI and has no catalyst monitor. That being said, I would still throw a universal cat on it for the simple fact it is illegal for the truck to not have a functioning catalyst.

You should find out what gearing your truck has in the diff, that can make a huge difference especially when using tires larger than stock.

 

[ronclark]

I getting almost 20 in the hi-way with my 4.0L i have 30s with 4.10 with a 5 speed
around 15 in town

 

[chazz79]

The truck came stock with 235/75/15 tires so I'm only 2 inches over design. I'll check for codes after work today. The light isn't on but I haven't paid attention at startup to insure that it has an operating bulb.

The cat deal is hillbilly but I'll address that in due time. I knew that ob1 threw the same mix into the cat no matter what.

 

[legoms013]

Whoops, I overlooked that fact it wasn't OBDII

 

[alwaysFlOoReD]

Reworked my #s and it's 18.2mpg[imp]=14.6mpg[us] city driving [delivering pizzas...so I'm not easy on it]

Richard

 

[fordracing60]

Try cleaning your maf sensor. Work wonders for me.

 

[shane96ranger]

The truck came stock with 235/75/15 tires so I'm only 2 inches over design. I'll check for codes after work today. The light isn't on but I haven't paid attention at startup to insure that it has an operating bulb.

The cat deal is hillbilly but I'll address that in due time. I knew that ob1 threw the same mix into the cat no matter what.

What trans do you have? If it's a manual, I noticed my Explorer did a lot better if I kept the rpm's down in the 2,500 - 3,000 when I shifted. It had 3.55's and I was running 30 inch BFG's. I got 17-18 mpg's. My truck was a 96 Ranger with 3.73's and an auto, and it got 15-16 mpg.

 

[chazz79]

The truck is an automatic. I have no codes and it runs great. I noticed the TV cable is slack and the trans shifts early as possible without lugging the engine. The shifts are so grandma mushy that I have to pay very close attention to notice them. I don't know if that's a problem. I can properly adjust the tv cable but later, firmer shifts are only bound to make my mileage problem worse?

No codes keor or koeo

 

[chazz79]

rear axle is an r6 3.73 limited slip 8.8"

 

[Maverick]

I had the same problem with a 92 Explorer I had. Only had 100K on it, ran like a top, all the tune up parts were new, free flowing exhaust etc. It had 3.55 gears and a 5 speed. Never once got better than 13mpg even with the stock tires on it. I sold the pile before too long. I did just a buy a 95 Ranger ext cab 4x4 on monday, has 235's and 3.27 gears. I found a bunch of hand calculated fuel mileage logs in the glove compartment from the previous owner and it looks like they got a consistent 18.7mpg out of it. I'm kind of skeptical of that myself, but I guess I'll find out.

 

[jmg8550]

Not true...his truck has no way of knowing what the cat is doing. It is OBDI and has no catalyst monitor. That being said, I would still throw a universal cat on it for the simple fact it is illegal for the truck to not have a functioning catalyst.

You should find out what gearing your truck has in the diff, that can make a huge difference especially when using tires larger than stock.

Wrong, some counties in the USA don't require emission testing. Therefore, exactly how is it illegal? Also, farm trucks (with farm plates) don't require catalytic converters because it can cause fires.