18mpg city 16 highway

[tomtoc]

my mpgs seem to have reversed lately

i used to get 18 or 19 on the highway, 13ish in town. now it seems to be 16 or so on the highway and 16-18 city.

someone please explain. my only thought is the rpms are too high on the highway. i'm at about 1800 going 65. driving in the city i shift about 2,000 max. makes sense that the rpms are consistently higher on the highway, but seems like i should be revving, shifting, and generally driving slower in the city.

any other guesses?

other possibly related question... it seems to run a lot smoother on premium gas than regular. on regular it feels like something is choking it while driving and runs a little rough at idle. timing? plugs/wires?

 

[O'Rattlecan]

The engine should be tuned for cheap gas. I'd think there might be an issue with the engine breathing?

Ryan

 

[Skandocious]

It's possible that you need some new plugs (referring the regular vs premium fuel question). Has it never had a tune up?

While doing the tune-up it would also be a good idea to check the timing.

 

[tomtoc]

It's possible that you need some new plugs (referring the regular vs premium fuel question). Has it never had a tune up?

While doing the tune-up it would also be a good idea to check the timing.

i did pretty much everything when i got it a year ago except spark plugs/timing.

air filter included

 

[Skandocious]

You did everything and didn't replace the spark plugs? LOL! That's like the most important thing.

I'd give her a good tuneup-- plugs, wires, cap/rotor. Then check the timing when you're done. If it's still running crappy then you will have eliminated that [highly likely] possibility.

 

[tomtoc]

You did everything and didn't replace the spark plugs? LOL! That's like the most important thing.

I'd give her a good tuneup-- plugs, wires, cap/rotor. Then check the timing when you're done. If it's still running crappy then you will have eliminated that [highly likely] possibility.

yea, i think i even have them in the garage too. i did most of it in 1 weekend and just ran out of time. it's gotten pushed to the back burner (for a year apparently).

any tips on replacing the rotor without totally screwing my timing (skan, recall the phone call when i did that to my 250)

 

[Skandocious]

Ahhh yes-- didn't you somehow put it 180* out of time?

It ain't hard-- I just kept the new rotor nearby and swapped it to exactly the same position when I took the old one off, then put the new cap on the way the old one was... I didn't do anything technical like marking the cap, etc etc. I just made sure the new cap/rotor look exactly the same as the old ones.

There's a full walkthrough somewhere on the net called a "sixlitre" tune up... I can't freakin find it.

 

[1985 Ford F-150]

Just find your number 1 cylinder and trace the plug wire back to the cap before ya take it off and mark the cap with a 1 where that wire goes and make a reference point on the motor as to where 1 is if ya need it. Find out what you firing order is and which way the rotor turns then just pull the cap off and pull the rotor out and put the new rotor in the same position. Then get your new cap and if its not already with a 1 then put it on the distributor just like the old one was and mark it that way, then just put your wires on in the right order and there ya go.

 

[Mr. Stroker]

Replacing the rotor.. It easily slides on and off. Just mark with a paint marker or sharpy. Also you can take a picture of it. Its slotted so its pretty hard to screw up. Good luck