13.5-14 mpg on 4.0 OHV 4x4?

[danaholic]

I've been plagued with terrible mileage since i got this thing. I was getting 12.5-13 before i ran seafoam through it. that helped a little and now it doesn't knock under acceleration. The truck bogs down if i try to accelerate under 1000 rpms and suddenly comes to life at 1500. if i floor it it loses all power and wont accelerate.....

Any suggestions?

 

[RyanD2]

I'm not sure what to say about the mileage, first thought would be to do a regular tune up, don't know if you've tried that.

I used seafoam in my 00 and afterwards had similar issues. Turns out everything dumped into cyl.4 and it wasn't even firing. Do you have a CEL on or anything or do you know if it's missing?

 

[chippy_69]

doin better then me

i don't wanna steal you thunder but i am having problems too. just bought my '03 FX4 3 (97KM) weeks ago, i knew i was taking a step down in fuel economy (had 93 4cyl 18mpg city) and i defintly did.
i know its winter and the past 3 weeks have been damn cold -20-30C. but each time i fill up my economy seems to be getting worse. i started at 11.5MPG and went down to 11, 10.5, 9.9, and the latest fill up was 7.9......it seams to run great i do plan to do a tune up, i have already changed ALL oils, air filter, and i have cleaned the throttle body (was fairly dirty and gave the truck a little more pep) i know the suggestion is gonna come up about taking it easy on the throttle......and ofcourse i have tried that.

i have never heard or seen fuel milage drop off like that on a vehicle that runs so smooth...any/all suggestions will be appreciated.

if i could ask, do the 03's have a pcv?? i checked at parts source the listed on up to 02 and 04+, the kid behind the counter was little to no help and i gave up on it after that.

 

[exbass94]

if i could ask, do the 03's have a pcv?? i checked at parts source the listed on up to 02 and 04+, the kid behind the counter was little to no help and i gave up on it after that.

Yes, they do. Go to Napa and ask for part # 2-9484. I found it in less than 30 secs. http://www.napaonline.com/MasterPages/NOLMaster.aspx?PageId=470&LineCode=CRB&PartNumber=29484&Description=Positive+Crankcase+Ventilation+(PCV)+Valve

 

[gw33gp]

That looks like the right one because it has a coolant line going to and from it. It is kind of difficult to replace once you figure out where it is. You have to disconnect the coolant lines and then you have to rotate the PCV to release it. There is not a lot of room to work in there either.

BTW, it is near the rear of the driver side valve cover.

 

[chippy_69]

that is it stuff back in there huh? i really hoped it wasn't.

on the bright side i got another minor weekend task
thanks for you help.

 

[Big Jim M]

Guys if it is that damn cold and you are making short trips.. or even long ones in the snow.. Your milage is about what I'd expect. If staying around town, your choke system is probably working and keeping the mixture very rich.
I know if it was that cold I'd be warming the vehicle before I went for a ride... THAT would ruin the milage all by itself.
Big JIm

 

[jmg8550]

Guys if it is that damn cold and you are making short trips.. or even long ones in the snow.. Your milage is about what I'd expect. If staying around town, your choke system is probably working and keeping the mixture very rich.
I know if it was that cold I'd be warming the vehicle before I went for a ride... THAT would ruin the milage all by itself.
Big JIm

What choke? Do you consider the engine idling higher at first start up a choke?

 

[Big Jim M]

What choke? Do you consider the engine idling higher at first start up a choke?

When the engine is cold the computer causes the mixture to be much richer than when hot.. Same as an old time "choke". The computer knows the outside temp as well as the engine temp. It adjusts the mixture as needed.
Big Jim

 

[chippy_69]

yes i realize that warming up your truck and driving in the extreme cold is gonna have a negatve effect to mileage but 5mpg? yikes...may have found part of the problem....had one ebrake(drivers) siezed and the other sticky (kinda embarassing)....now i don't know how much they were enaged when they stuck but i didn't really feel the back end dragging.....i will know better after they are relplaced today

 

[darkspork]

yes i realize that warming up your truck and driving in the extreme cold is gonna have a negatve effect to mileage but 5mpg? yikes...may have found part of the problem....had one ebrake(drivers) siezed and the other sticky (kinda embarassing)....now i don't know how much they were enaged when they stuck but i didn't really feel the back end dragging.....i will know better after they are relplaced today

My Ford Ranger replaced my Pontiac Vibe. I haven't had the Ranger long enough to calculate fuel economy but I can say this: During the summer the Vibe would get 34mpg on long trips and about 29mpg on average doing about 80% highway driving. During the winter I'd get an average of 21-23mpg and see as low as 18mpg. So on average I would lose 6-7mpg (20%) and as much as 11mpg (37%). Of course my driving habits are much different in the winter, in that car I would shift at about 2000 rpms during the summer whereas in the winter I'd shift at about 2500 to prevent bogging when the engine is not warmed up and so that I could utilize engine braking, also I would have scrape the ice off the windows, then have a smoke while I let it idle on days below 0 degrees Fahrenheit. The winter blend of fuel should also be considered. But back to my point 5mpg is about a 25% decrease which sounds pretty normal for cold winters.

 

[Chris.S.]

My 4.0 gets about 14-15mpg in the cold weather.

 

[redneck15431]

Back in the summer my 94 4.0 was getting around 17, and when the weather really started getting cold I started getting about 14 and it's still that way. I actually just clocked my 04 4.0 last night and it came out to about 13. I'm curious to see what it's gonna do this summer.

 

[redknight]

1996 Ranger with the 4.0L (176K on the ODO)
manual hubs\manual 4x4\manual trans

OK, my ranger has its share of issues, but I normally get 16 - 20 mpg year round with not a huge difference between winter and summer. Maybe my ranger is one of the odd exceptions in that one area, but the only time I can think of getting less was when we had 2 or 3 snow storms over a week and I had to keep the hubs locked the whole time and keep it in 4-wheel drive 85-90% of my 32 mile (each way) commute to work. Even then, I think I still got 12 - 14 mpg. I compute my mileage averages by dividing total miles driven by number of gallons to fill ignoring highway\city or driving style. I guess I'll keep counting my blessings.

 

[chippy_69]

. But back to my point 5mpg is about a 25% decrease which sounds pretty normal for cold winters.

i guess when you run the numbers it sounds a little more realistic, i ahve only had it a short time as i said so its hard to tell, but whenever i have a little spare time i have being doing the minor tune up stuff, and noting mild improvements each time (im about 12 mpg now) , the next 2 priorities are fuel filter and PCV so hopefully i can reclaim some economy in those parts.

as for now i will just grin and bare it, i still got a huge 'step up' from my 93 2.3 with 315k, with the mileage, engine size and driving habits i was sitting around 15mpg, if i can get back to that point i will be happy