Most of the two years I have had my FJ62 it has been all torn apart--paint, suspension, repairs, etc. Now that I have been driving it consistently, I decided to try to do something about the 10 MPG I have been getting. I mean 150 miles out of a $50 tank of gas is painful. My rig is a stock 3FE and drive train except for the ARB suspension and 31 inch tires. I have not been compensating at all for the 31 inch tires, I just drive it and do my MPG calculations right off the speedometer/odometer. So, I figured I should at least be able to get the 12 to 14 miles per gallon that the window sticker claimed it would get when it was new.
So, I started down the Poor Gasoline Mileage troubleshooting chart in the Repair Manual. I pretty quickly eliminated the simple things like fuel leak, dragging brakes, dirty air cleaner, incorrect ignition timing, idle speed, spark plugs and tire pressure. That left the more involved items. So I pulled the EGR valve off to take a look. It has a long pipe with a hole at the end that sticks into the intake. The hole and the pipe were almost completely plugged with carbon. AH-HA I thought! A smoking gun. So I ordered up a new EGR valve and modulator from Cruiser Dan (it's an expensive sucker). After installing these new parts, I ran through a tank of gas. It seemed to have a little more power, or should I say it seemed to be a little less gutless. I mean, I can now actually accelerate going up the freeway on-ramp and hit freeway speed by the time the on-ramp ends! But, at the end of the tank of gas, I had still only gone 150 miles. Rats. Well, OK, on to the next item. I bought a new PCV valve and rubber grommet (the old grommet was hard and brittle). I wouldn't be surprised if the PCV valve was original. I compared the old one to the new one. The old one still rattled, but it wasn't a clean sounding rattle like the new one. So I installed the new parts and started driving. Driving included some highway driving, a couple of hours of wheeling in 4 LO, and driving around town. I got 200 miles out of this first tank of gas following the PCV valve replacment. I calculated MPG and I got 12.5 MPG out of this tank of fuel! Yes, positive improvement. I'm not the guy to explain why, and I plan on running through a couple of tanks of fuel before I declare positive success, but the initial results look promising. PCV valve and grommet are just a little over $10, so I almost paid for it with the first tank....And you might also want to check your EGR system.
So, I started down the Poor Gasoline Mileage troubleshooting chart in the Repair Manual. I pretty quickly eliminated the simple things like fuel leak, dragging brakes, dirty air cleaner, incorrect ignition timing, idle speed, spark plugs and tire pressure. That left the more involved items. So I pulled the EGR valve off to take a look. It has a long pipe with a hole at the end that sticks into the intake. The hole and the pipe were almost completely plugged with carbon. AH-HA I thought! A smoking gun. So I ordered up a new EGR valve and modulator from Cruiser Dan (it's an expensive sucker). After installing these new parts, I ran through a tank of gas. It seemed to have a little more power, or should I say it seemed to be a little less gutless. I mean, I can now actually accelerate going up the freeway on-ramp and hit freeway speed by the time the on-ramp ends! But, at the end of the tank of gas, I had still only gone 150 miles. Rats. Well, OK, on to the next item. I bought a new PCV valve and rubber grommet (the old grommet was hard and brittle). I wouldn't be surprised if the PCV valve was original. I compared the old one to the new one. The old one still rattled, but it wasn't a clean sounding rattle like the new one. So I installed the new parts and started driving. Driving included some highway driving, a couple of hours of wheeling in 4 LO, and driving around town. I got 200 miles out of this first tank of gas following the PCV valve replacment. I calculated MPG and I got 12.5 MPG out of this tank of fuel! Yes, positive improvement. I'm not the guy to explain why, and I plan on running through a couple of tanks of fuel before I declare positive success, but the initial results look promising. PCV valve and grommet are just a little over $10, so I almost paid for it with the first tank....And you might also want to check your EGR system.
