new plugs and wires now getting 25 instead of 27 mpg. not cheapo parts either.1998 3800 v6
2006-11-06 00:05:04 · 9 answers · asked by eric c 2 in Cars & Transportation ➔ Maintenance & Repairs
During the tune up, was the base timing set? If it's a GM car, the timing is controlled with the PCM. If the thermostat is stuck open or has been removed, the transmission wont go into over drive and fuel mileage will decrease. The engine has to be at operating temp for the OD to work. If the O2 sensor hasn't reached 500 degrees, the computer won't go into closed loop and OD won't work. Also the coolant sensor has to show the computer that the engine is at operating temp for it to work properly. If the check engine light is on, have a scan run on it and the stored code will lead you to the problem.
Check the tire pressure and be sure you didn't inadvertently disconnect any wires or vacuum hoses.
Hope this helps.
Master tech 40 yrs.
2006-11-06 00:15:45 · answer #1 · answered by Cal 5 · 1⤊ 0⤋
A tune up doesn't just consist of plugs and wires! Might want to consider a complete tune up and then possibly your mileage will increase--slightly. Have to keep in mind as you drive the car and the engine wears, so will your mileage decline! I wouldn't put a whole lot of emphasis on 2MPG! When you lose 5 or 10 then I would concern myself.
2006-11-06 00:15:37 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Replacing O2 sensors can worsen mileage a bit, since bad ones tend to make the engine run too lean.
2006-11-06 11:31:29 · answer #3 · answered by Nomadd 7 · 0⤊ 0⤋
You should get better gas mileage. Check the air in your tires. That makes your gas mileage worse if wrong amount of air in them.
2006-11-06 00:09:23 · answer #4 · answered by Becky 2 · 0⤊ 0⤋
the first 3 internet internet sites are ford men that restoration their own Rangers and in all likelihood have education you should use for different issues besides mpg.The very last website is that you'll evaluation & see if it would want to help strengthen the MPG's.
2016-11-28 20:11:54 · answer #5 · answered by ? 4 · 0⤊ 0⤋
Did you reset or check the timing? Check that all your vaccumn lines are connected.Make sure all spark plugs are tight.
2006-11-06 00:09:42 · answer #6 · answered by ? 4 · 0⤊ 0⤋
Did you take it to Scotty's Service? If so, that's par for the course.
2006-11-06 00:16:25 · answer #7 · answered by Suzan 3 · 0⤊ 0⤋
If you didn't do the tune-up yourself, then I'd take it back and complain! If you did! Then I'd keep my mouth shut!!! lol.
2006-11-06 00:11:53 · answer #8 · answered by wheeliebin 6 · 0⤊ 0⤋
Have you aired up your tires since it has cooled off?
2006-11-06 00:08:14 · answer #9 · answered by tumbleweed1954 6 · 0⤊ 0⤋