What's a tune up?

_____________________ Hello! Just getting back from 1968 here. Just finished the points, spark plugs, adjusting the spark timing & the dwell, putting in new oil & filter & replacing fuel filter & checking the float bowl on a '65 New Yorker.

It's easy here in '08, what with electronic fuel injection & variable valve timing. Not much to a tuneup for cars less than 15 years old. New plugs after 50,000miles, Air filters every 5 - 15,000 miles depending on what you drive, and oil changes can be spread out to

As far as cleaning the fuel system goes, if you suspect it's never been done on a car with that much mileage,(what's the year & make btw?) I'd go with a throttle-body cleaning(properly done) and a new set of plugs. Also, check the spark plug wires. Very often after- markets will outperform the originals especially if they're more than

Valve timing(crank angle) and ignition timing are two different things. On a car from 1990 & up, ignition timing is electronically controlled and almost never needs human intervention. Was the drop in MPG sudden, or spread out over several months?

-CC

Don't know. Checked in February, again in early July. Change was in the intervening months. It was ignition timing the ads for tuneups referred to. My impression is same as yours- little likelihood it really needs to be checked.

Not a whole lot involved in tune-ups these days. Without knowing the year, timing is probably not adjustable. Change the plugs. Change the gas filter every 20k miles. Air filter when needed. Ignition wires are change for preventive maintennance or if you have a miss and you done the above. With 1300k miles on it, and if you never have, don't fool with cleaning the injectors. It can open the proverbial "can of worms." (cause more problems/break garf loose from lines and clog up injectors/some automakers say don't clean)

____________________ Actually I would LIKE to change the fuel filter in my 2005 Malibu(see related post this n.g.) which is approaching 28,000mi, but the brilliant engineers at GM installed it INSIDE the gas tank with no specified change interval! The labor to empty & drop the tank, install the filter, and re-hang tank would never be made up in fuel savings no matter how long I own this car.

My mpg on that car is dropping an average 2mpg per year since buying it new in '05.

-CC

Why do you think that changing the fuel filter would result in -any- fuel savings, increase in fuel economy or solution to your dropping 2 MPG per year dilemma?