18mpg on a stock 5.0
04-28-2006, 02:41 PM
#1
Thread Starter
Join Date: Mar 2006
Posts: 30
18mpg on a stock 5.0
I have owned my 1990 5.0 for ten years and 75,000 miles and it always averaged 23.5 miles per gallon until last year when one day it started using a lot more gas. It was like a light switch had been thrown and it then averaged 18 mpg.I always maintained the car very well.I started replacing parts in hopes of fixing the problem,here is a list of what I replaced spark plugs, wires,cap, rotor, coil, tps, map,maf,computer,o2 sensors,coolant temp sensor, and air intake temp sensor,I also hade the injectors cleaned with the 3m kit that attaches to the fuel rail and the car idles on for a have hour.I checked the fuel pressure regulator also, after doing all this the car still gets 18mpg any ideas?
04-28-2006, 02:50 PM
#2
1st Gear Member
Join Date: Apr 2006
Posts: 101
RE: 18mpg on a stock 5.0
How much did you spend to replace all those parts? Or better yet how many gallons of gas could you have bought with that money? I owned my 5.0 since it was brand new in 1991 Its all stock and I have always gotten between 17 and 19 MPG.
04-28-2006, 03:23 PM
#5
Thread Starter
Join Date: Mar 2006
Posts: 30
RE: 18mpg on a stock 5.0
yes the timing is ten degrees and when I calculated my fuel economy it was driving to and from work witch is 66 miles round trip and mostly highway driving.The computer,maf,and map belong to a friend.
04-28-2006, 05:24 PM
#8
5th Gear Member
Join Date: Nov 2004
Location: Texas
Posts: 3,834
RE: 18mpg on a stock 5.0
ORIGINAL: runsrich
I have owned my 1990 5.0 for ten years and 75,000 miles and it always averaged 23.5 miles per gallon until last year when one day it started using a lot more gas. It was like a light switch had been thrown and it then averaged 18 mpg.I always maintained the car very well.I started replacing parts in hopes of fixing the problem,here is a list of what I replaced spark plugs, wires,cap, rotor, coil, tps, map,maf,computer,o2 sensors,coolant temp sensor, and air intake temp sensor,I also hade the injectors cleaned with the 3m kit that attaches to the fuel rail and the car idles on for a have hour.I checked the fuel pressure regulator also, after doing all this the car still gets 18mpg any ideas?
I have owned my 1990 5.0 for ten years and 75,000 miles and it always averaged 23.5 miles per gallon until last year when one day it started using a lot more gas. It was like a light switch had been thrown and it then averaged 18 mpg.I always maintained the car very well.I started replacing parts in hopes of fixing the problem,here is a list of what I replaced spark plugs, wires,cap, rotor, coil, tps, map,maf,computer,o2 sensors,coolant temp sensor, and air intake temp sensor,I also hade the injectors cleaned with the 3m kit that attaches to the fuel rail and the car idles on for a have hour.I checked the fuel pressure regulator also, after doing all this the car still gets 18mpg any ideas?
What about O2 sensors? they can mess w/ your A/F ratio when they crap out.
