PDA

View Full Version : help! bad mpg


lawnfreak09
03-30-2009, 08:06 PM
i have a 97 f-150 with a 4.2 liter v6. I am getting 11 mpg without pulling the trailer. I put new plugs, wires, air filter and ran some injector cleaner. All of this has not helped. Any idea's would be much appreciated.

J&R Landscaping
03-30-2009, 11:21 PM
How many miles on the truck? Have you replaced your PCV valve??

4.3mudder
03-31-2009, 12:09 AM
The problem is circled on the front of your grill. lol

lawnfreak09
03-31-2009, 03:42 PM
there is 102,xxx on the truck and i have not replaced the pcv valve.....

lawnfreak09
03-31-2009, 03:43 PM
must be a chevy driver

4.3mudder
03-31-2009, 08:32 PM
must be a chevy driver

That would be correct.

What did your plugs look like when you took them out?

South Florida Lawns
03-31-2009, 09:04 PM
11 mpg. what's your driving style? Because i could get that all day long driving like an ******* in my 4.3 chevy.

Edmonds Lawn Service
03-31-2009, 09:29 PM
i have an f150 too and i get about the same...mine is the 5.4 and its a 4x4. thats just ford for you. Chevy gets better gas milage period. I have a chevy 1500 that is lifted bigger tires and all and it still gets better gas milage than my f150

4.3mudder
03-31-2009, 09:59 PM
I think the ford tends to run richer also. I have a buddy that has a 2002 f150, and his tailpipe is black, I mean dark black, his is a v6. Maybe they have them from the factory to run rich. which, running richer will tend to use for fuel in conjunction.

lawnfreak09
03-31-2009, 10:34 PM
the plugs looked like sh** and the wires were the factory wires from 97 could not believe it. And i drive like an old man. i dont ever hot rod it....it is a v6 what is the point.lol

4.3mudder
03-31-2009, 10:52 PM
Well, if the engine is getting that bad mileage, you might be having air restriction, and that might be from the PCV valve. usually if an engine has a hard time breathing through the intake it will get air from the crankcase and that will tend to have the plugs a nasty color. So, you might have air restriction thus burning more fuel.

Edmonds Lawn Service
04-06-2009, 01:22 AM
^^^^I got told my O2 sensor might be going bad...would that mess with my trans or do you know?

albhb3
04-06-2009, 04:16 AM
I though this was gonna be a whiney I have a F550 gasser thread

addictedtolandscaping
04-06-2009, 07:45 AM
change your pcv and then upgrade your air cleaner to a k&n or similar. The more air you can get in within reason the better she will run. I always pick up a couple mpg when I change the air filters. I just put one in my 01 2500 with the 360 and noticed a real difference already.

GreenLightLawnCareInc
04-06-2009, 12:05 PM
I would check your intake plenum gaskets....good way to check them is to have the engine running and spray a bit of carb cleaner down around the bottom of the intake tubes. If it revs or you notice it running a bit different then the gaskets/ bolts and isolators are bad...I worked at a Ford dealership for 6 years and the 4.2 V6 engines had problems with that all of the time. Make sure you don't try to get by cheap and just replace the gaskets...bolts must be done to b/c of the isolator gasket made on them. Good luck with that truck...a 4.2 engine is a bored out 3.8 v6 from a ford windstar van....usually they don't last much past 100k. :dizzy:

topsites
04-06-2009, 12:59 PM
Well shoot dude :p
You did change the oil in it?

But if you did the wires and the plugs...
You got to do the cap and rotor.

GreenLightLawnCareInc
04-06-2009, 06:28 PM
Well shoot dude :p
You did change the oil in it?

But if you did the wires and the plugs...
You got to do the cap and rotor.

They dont even have caps and rotors....

4.3mudder
04-06-2009, 06:31 PM
They dont even have caps and rotors....

:laugh::laugh: He must be used to the older generation vehicles.

Milwaukee
04-06-2009, 09:53 PM
Do engine light on now?

Check oxygen sensor and question is cat converter clog?

is brake drag on it?

it should get 17 mpg

topsites
04-07-2009, 10:18 AM
:laugh::laugh: He must be used to the older generation vehicles.

So what do they have nowadays, one coil per cylinder?
That's nothing new, just an expensive way of doing things, thou I'm guessing there must be a reason.

Heck it's a 97, my 95 truck has a cap and rotor, but my 91 car doesn't (yes a coil per cylinder).
Or is there an electronic spark distributor of some kind or what?

Anyhow, 02 sensor.

4.3mudder
04-07-2009, 10:25 AM
So what do they have nowadays, one coil per cylinder?
That's nothing new, just an expensive way of doing things, thou I'm guessing there must be a reason.

Heck it's a 97, my 95 truck has a cap and rotor, but my 91 car doesn't (yes a coil per cylinder).
Or is there an electronic spark distributor of some kind or what?

Anyhow, 02 sensor.

Ya, everything is controlled by the computer. The wiring harness goes to everthing on the engine. Just like multi port fuel injection instead of a TBI or carb, same difference.

GravelyNut
04-08-2009, 11:58 PM
So what do they have nowadays, one coil per cylinder?
That's nothing new, just an expensive way of doing things, thou I'm guessing there must be a reason.

Heck it's a 97, my 95 truck has a cap and rotor, but my 91 car doesn't (yes a coil per cylinder).
Or is there an electronic spark distributor of some kind or what?

Anyhow, 02 sensor.
Nothing new is right. We've owned several engines that had a coil per cylinder and no rotor or cap. 3 cylinders with 3 coils and 3 sets of points. From the 50s and 60s.

glfredrick
04-09-2009, 11:56 AM
To up the miles per gallon try a couple factors.

1) Engine speed. Too low or too high an rpm will hurt mileage. Gearing is the typical way to change rpm, but it can also be accomplished with tire size. Have you gone up or down in tire size? What rpm are you running while doing most of your driving? If it is low (like below 1500) you are lugging. You'll get better mileage by letting it rev a bit more. Shift out of OD and use a lower gear.

2) Efficiency. You can get efficiency in the engine in a couple of ways. First, make sure it is tuned properly. You've already done some of that, but in a PCM controlled engine, the O2 and other sensors are all part of the tune. They need to be working correctly AND sending the right signals to get the engine into closed loop so it will begin to self-regulate and operate best. Second is to use true synthetic oils -- I prefer Amsoil. They generally spin over easier, especially at cold start, which for you is probably every time you pack up and leave a job site. They cost more on initial change, but you can run extended drain intervals and save money in the long run. Third is to get the air in and out best. As already suggested, an aftermarket air filter, cold air intake (CAI) and making sure your cat isn't plugged, then, if need be based on your present exhaust, a cat back exhaust system to exit the gases. The idea here is to not go BIG for the sake of big, but to go FLOW for the same of flow -- as long as you don't hurt extraction. Surf Ford truck forums to see what others are doing. I prefer True Flow or Amsoil air filters. True Flow also probably makes a CAI that will boost horse power around 10 on your truck. They filter better than K&N, which is good in our dusty business.

3) Suspension and axle efficiency. Make sure you don't have worn/rubbing brakes or e-brakes. Make sure your wheel bearigns are good. Replace transmission and differential (and transfer case if it is 4x4) with synthetic oil. Air up tires to the max recommended pressure. If you are trailering, make sure that your trailer axles and brakes are good and not dragging.

4) Transmission. Make sure it is no slipping. No additive will really help, if it is a problem get it repaired or rebuilt. With a V-6, you probably have a version of the A4LD or one of its newer versions like the 5R55E. They are not known for longevity.

5) Cut down the weight. It takes hp and fuel to move weight. Eliminate as much as you can.

6) Good fuel. Decent gas will net you a couple of more mpg than crud. I've noticed a distinct difference from some of the price leaders and name brand gas in my area. Test different fuels from different stations. The one with the best lunch may not be best for your bottom line profit!

Otherwise, about the only other alternative is a different vehicle that is designed to be more fuel efficient.

mnglocker
04-10-2009, 01:02 PM
Trade it for a truck with deeper gears or more low end torque. That little v6 has to be working it's ass off to move the truck, let alone your gear and/or trailer.

fool32696
04-10-2009, 03:34 PM
My 2001 4.6 v8 gets 20mpg + on the highway 15 in town and 9-10 pulling 4000 lbs (it has 114,000 miles on it). Ford recently discontinued the V6 because the gas mileage wasn't any better than the small V8. Sounds like you do have a problem though. That truck without a trailer shouldn't get less than 15mpg.

hsieh
05-04-2009, 07:18 PM
so what truck gets the best miles per gallon?

i wanted to buy a chevy hhr to pull a trailer and ztr but the trailer at Lowe's is

2000 lbs itself. they told me the hhr can pull 1500 lbs at the most.

i was also told that a 2 wheel drive with a v-6 engine gets better mpg.

glfredrick
05-05-2009, 06:08 AM
Chevy trucks are typically rated higher in miles per gallon than other makes. Just pick one that works for you and research it before you purchase.

A Trailblazer might also be a decent choice if you don't need a truck. In the right configuration they are good for 7000 pounds. I've towed more than that with mine. It would still get above 12 mpg while towing heavy in 3 (never OD for heavy towing). It DOES need an additional transmission cooler.

I get 20+ in freeway running without trailer. Around 15-16 in town driving.

hsieh
05-09-2009, 09:39 AM
i made a mistake the trailer isn't 2000 lbs it can carry 2000 lbs. my chey hhr can haul 1200 lbs. also the hhr gets good gas mileage and i can use e85 but they say it's not a efficient. a small ztr is about 450 lbs.

what do you use to secure the ztr so it doesn't roll around on the trailer?

thom
05-09-2009, 01:18 PM
i have a 97 f-150 with a 4.2 liter v6. I am getting 11 mpg without pulling the trailer. I put new plugs, wires, air filter and ran some injector cleaner. All of this has not helped. Any idea's would be much appreciated.

11 mpg is not good.
what method are you using to check the fuel usage?
the mpg can be improved.

Dountman
05-09-2009, 04:43 PM
Locking Gas Cap. haha

BCarlson
05-10-2009, 12:20 AM
^^^^I got told my O2 sensor might be going bad...would that mess with my trans or do you know?

If you have coil packs that could be the cause of the poor mileage also, if you do have coil packs get them changed before it blows your piston rings. 97 I bet they haven't been changed and the should be changed every 80,000 miles. My engine light came on and it showed up at first as the O2 senser.

mjlcare
05-15-2009, 10:40 AM
fuel filter, i have a 02 f150 supercrew 5.4 and was getting like 14-15 on the highway, 11-12 city. changed fuel filter, $10. now im getting 17-18 on interstate and 13-14 city.

cant really complain anymore, with that engine

unkownfl
05-15-2009, 12:14 PM
If it has all the power then the cats are not the issue. First get a can of sea foam apply it into the smallest vacuum port of the intake and clean the carbon inside. After that change the plugs and oil again. If you have not changed the air filter do so. Buy two o2 sensors 50 bucks a piece. You will know win you need coil packs on a ford the truck will totally break down when trying to get on it like it is running out of gas. I would get a vacuum gauge and check the vacuum as if it is low then you are running high fuel pressure because vacuum operates the fuel regulator. At the end of the day you are still getting bad mileage get a locking gas cap or take your lead foot of the peddle.