Gas Hog

[Crankin]

Hey guys I was wonderingif anyone else has had this problem, and what you did to fix it? My FSB 5.8 EB edition is using way more gas then usual. I have no check engine lights on, it drive fine, runs fine, but I can actually watch the gas gauge move if I'm sitting for just a few minutes idling, and driving short or long distances. I was getting normal gas mileage before for a FSB, but all of a sudden we're talking like 5-8miles to the gallon now, where I was getting 13-15 before. [-o<

 

[Seabronc]

I'd start by checking for possible fuel line or tank leaks. Then I'd do a real good tune up. The gauge moving around is not unusual. It could be simply be due to fuel slopping around, the sender unit or variations in the gauge voltage. My gauge has never been accurate and I'm on my second sender unit.

Good luck,

>-

 

[mbtech2003]

I agree with Seabronc their might be a gas leak. broncos are known for their gas tanks rotting out. check that out. also the oxygen sensor could be getting "lazy" and giving wrong readings to the engine computer. how many miles on it and what year is it?? is their a drop in performance when driving?? check the fuel pressure regulator on the back of the fuel rail. let us know

thanks @-)

 

[snowman74]

Must agree. Also, IF you have to replace tank do two preventative things: 1. place heavy gauge rubber strips between hangers and tank. A lot of rust occurs there. 2. Go ahead and replace your valve breather filter and air filter just for kicks. You might have gone through a really nasty cloud of dirt and not thought of it. Those filters will DRAMATICALLY decrease fuel economy when dirty. My two cents.

Snowman >-

 

[Crankin]

106k on the clock, its a clean, stock 5.8, but lifted 4" (superlift) 33' tires. I cleaned the K&N filter, checked fuel pressure (30psi), checked for leaks, checked plugs, did a complete fuel system cleaning, no major drop in performance, except its a bit doggy when passing on the interstate. If you let it sit and idle for 5 mins you can actually see the gaige move in that 5 mins. Next I will do a complete tune up, scan for codes, check the converter, posibly replace to O2's, etc.

what is everyone else getting for mileage? (what's normal)

Thanks guys!

Crankin

 

[mbtech2003]

i'm at 10-11mpg right now with 32's and some eng mods >-

 

[gungho]

I had a similar problem on my 93. It burnt a half tank of gas in 100 miles. Turned out to be the gas cap was bad leaking out all the fumes

 

[firelt90bronco]

Being an automotive mechanic, I would check filters (fuel, air) and check the sending unit for the fuel. Check tire pressure and use injecter cleaner. I got 4 miles to a gallon before I did all these things and now I get about 20.

 

[highriderW13]

im getting about 6.5 to 8 and ten if im really lucky

 

[snowman74]

I gotta ask... What is the best mileage ANYBODY ever got in their 5.0 or 5.8 L Bronco? At one point I was getting upwards of 400miles per tank in my 5.0...no mod's. I thought I'd get better when I put headers on and went dual exhaust. I'm lucky if I get 300 miles to the tank...just under 10 miles per gallon...and mines an 88' with 4wd. Hey...come to think of it...are your hubs locked? Probably not...if you're in an EB edition it's got auto lockers on it.

What's it idleing at? Are you running rich? Changed your oil lately? Just a few thoughts.

Snowman

 

[Crankin]

Thanks for all the info!

My Bronco runs great, I sea foamed it twice, No check engine lights, idles @ around 700, fresh synthetic oil change, new K&N Air filter, 35psi in the tires, auto hubs but they don't work (no 4wheel drive) and I'm switching to warn hubs, wondering if the cat or muffler is messed up???? I'm buying everything to do a complete tune up: plugs, wires cap & rotor, pcv, new coil. I even tried the accetone trick which does help a little.

http://www.lubedev.com/smartgas/

 

[American Rebel]

I would take it to a shop and tell them to do a power balance test. The test determines if all cylinders are pulling their equal load. It disables one cylinder at a time, monitors the RPM drop, and moves on to the next cylinder. It then looks at all the RPM drops, and whichever cylinder is 15% lower than any of the others, you have possible injector problems, or a fouled up spark plug.

At my tech shop, we have a machine that does this. I hooked it up to my Bronco and it showed I had a weak cylinder, turns out it was a bad injector. Now, my MPG has gone to the premium MPG of 17 MPG /emoticons/[email protected] 2x" width="20" height="20" />

Any slight problem with the injectors or a spark plug can really hurt your MPG. So, make sure everything is in top shape.

As far as a leak, the engine would not run or would be very weak. It would also trigger a fault code in your computer as a problem with the fuel pump. Since you said that the Check Engine light doesn't come on, a leak would be the last thing that could cause bad MPG.