1996 F-150 302

[adam123]

This thing has good power is doing reasonably well for its milage around 150K. But this things is a dog on gas it gets around 9MPG. Anybody know what the problem may be,Or is this just the nature of this engine.

 

[Gary Allan]

You're in big block range towing something.

You don't happen to have bigger than stock tires on it, do you?? Still, they would have to be radically bigger to account for about 5-6 mpg.

 

[wileyE]

I have a 92 f150 4x4 auto, 15-18mpg. I picked up a couple mpg on mine when I cleaned the injectors and changed the fuel filter. Serviced the transmission and reset the computer at the same time, not sure what did it. Seemed to be running fine before , but ran even better after I was done.

Like gary said, big tires can really kill the mpg? could that be your problem?

 

[wander2039]

If the tires are bigger they won't kill your gas mileage only appear to. The bigger the tire less the revolutions it needs to take to go a certain distance. In otherwords your speedo will be wrong so unless you get in calibrated you won't know the actual gas mileage your getting.

 

[adam123]

Nah its the same tire size as stock.

 

[wander2039]

BTW have you had a tuneup lately? These 302's really like new plugs, and the correct timing. Cleaning the intake - tb,egr, iac, wouldn't hurt also. My dad's 302 went from 9 to 15-16 with a fresh tuneup.

 

[adam123]

I was planning on doing that when the warm weather comes back around mid February. I might have to bump it up to January.

 

[brianl703]

A common problem with the balancer on the 302 is that over a long period of time the outer portion of it moves, rendering the timing marks incorrect. That's what happens before the middle rubber piece completely deteriorates and the outer ring hits the timing cover, damaging it.

 

[punisher]

From my faulty memory: I think '96 was the last year for MAP sensors on trucks (calibration dependant). I always checked the MAP sensor first for any mileage concerns. A broken/cracked MAP vac line as well as a faulty sensor is not uncommon. Check the vac line to it, check the vac line for cracks where it plugs into the nipple on the sensor, check the internal surface of the line for any "jelly" like substance (an indication of the sensor coming apart internally).

If by chance you have a MAF sensor, ignore the
above.

After that verify correct fuel pressure, timing and find someone with a scanner to keep an eye on your O2 sensor voltages/crosscounts.

 

[Islandvic]

Decarbonize combustion chambers with 2 treatments of SeaFoam

Change Plugs After SeaFoam cleaning

Run SeaFoam in 2 consecutive gas tanks

Change PCV valve

Change Fuel Filter

Clean TB

Clean MAP/MAF sensor with Quick Dry Elect Cleaner

Check Timing

Drain Refill trans fluid

Change o2 sensor

 

[andyd]

other things to watch are driving style, tire inflation, air filter. dragging brakes, slipping transmission.

 

[Shaman]

Also, check the PCv valve filter below the PCV valve.