bad fuel mileage
Thread Starter
|
New User
Joined: Aug 2005
Posts: 5
Likes: 0
bad fuel mileage
I have a 95 F150, 4.9 5 speed that is getting only 9 to 10 mpg but the truck idles fine and runs well except for a small mid throttle stumble. Had a new exhaust put on from the converter back. My mechanic fixed an intake and exhaust leak and put a new EGR, Egr solenoid, air charge sensor and temp sensor. The sparkplugs were and are still white indicating a lean mixture even after repairs. I ran a can of Seafoam through the EFI and the tank and it helped somewhat but the mileage is still in the toilet. The air charge tube was leaking so he removed it telling me that it would not hurt the performance. Any ideas or suggestions would be helpful.
Posting Guru
Joined: Sep 2002
Posts: 2,420
Likes: 3
From: Langhorne, PA
Is it a daily driver or is it hauling loads in the back everyday?
My 92 300/E4OD is running the best ever, I can only get 14.000000 MPG's out of her just going back and forth to work.
Is the coolant level stable or do you have to add a quart to the reservoir every week? What color is your exhaust and how does the exhaust smell? How many miles on the engine? Are you a lead foot?
The tube that is missing...is that the smog pump tube running fresh air to the CAT Convertor, or the tube that comes off the exhaust that feeds into the EGR and upper intake?
Also, you may need to learn about the IAC operation, it may be fouled with carbon.
Have you tested the vacuum on that engine lately???? 20 to 22 inches of pull would be very nice.
My 92 300/E4OD is running the best ever, I can only get 14.000000 MPG's out of her just going back and forth to work.
Is the coolant level stable or do you have to add a quart to the reservoir every week? What color is your exhaust and how does the exhaust smell? How many miles on the engine? Are you a lead foot?
The tube that is missing...is that the smog pump tube running fresh air to the CAT Convertor, or the tube that comes off the exhaust that feeds into the EGR and upper intake?
Also, you may need to learn about the IAC operation, it may be fouled with carbon.
Have you tested the vacuum on that engine lately???? 20 to 22 inches of pull would be very nice.
Postmaster
Joined: Aug 2004
Posts: 2,908
Likes: 2
From: West Mansfield, Ohio
That could be exactly your problem. A faulty O2 sensor will not read right which will let your engine run lean or rich. It assumes everything is fine the way it is when really its not.
Thread Starter
|
New User
Joined: Aug 2005
Posts: 5
Likes: 0
The truck is a daily driver and I don't haul any loads. The engine has 27000 miles on it. I used to average 18 hwy and 15 city. I have driven it very easily not pushing over 2000 rpm and there was no increase in the mileage. The coolant level is fine and there are no leaks. I will check the IAC to see if it is fouled. Can the O2 sensor go bad and not throw a code in the computer.
Trending Topics
Postmaster
Joined: Aug 2004
Posts: 2,908
Likes: 2
From: West Mansfield, Ohio
Yea. Typically thats what will make your computer throw a code. If your truck instantly got that bad of mileage and theres no code, then change the O2 sensor and then a new one could tell you what the problem is. The O2 sensor could think theres a rich mixture (although it could be wrong) and could tell the computer to lean the fuel up a little bit, causing a lean mixture. If I remember right, if an engine runs too lean, the MPG's will go down. Not sure though...
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
3 Best / Worst Features Of The 2025+ Ford Expedition
Brett Foote
10 Ways Ford is LOSING to the Competition
Joe Kucinski
Top 6 Best Deals Available on New Fords & Lincolns Right Now
Brett Foote
This Hennessey Takes the Expedition Tremor's Off-Roading Capability to the Next Level
Verdad Gallardo
Top 10 Fords at 2026 Carlisle Ford Nationals
Joe Kucinski
3 Best / 3 Worst Parts of Modern Ford Ownership
Brett Foote
10 Amazing Upgrades That Solve Common Ford Truck Owner Headaches
Pouria Savadkouei
Every 2026 Ford Engine Explained
Brett Foote