Horrendous gas mileage
#1
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Horrendous gas mileage
So the pas few weeks I have noticed a HUGE drop in mileage. From about 16-17mpg down to 11mpg. I am trying to find out what is causing the drop in mileage. I have just put new plugs, wires, cap and rotor in, new ox sensor aswell. I did however have my intake mani off, and after reading a few threads, I'm thinking I may have broken off the barb for my TVV.
I'm wondering if the TVV not working would cause the huge drop in mileage? I have also found it may be my fuel damper that is leaking. I am getting a slight STALE fuel smell from time to time, so I am thinking fuel vapor and EVAP system before the damper that would be raw fuel.
Any thoughts?
I'm wondering if the TVV not working would cause the huge drop in mileage? I have also found it may be my fuel damper that is leaking. I am getting a slight STALE fuel smell from time to time, so I am thinking fuel vapor and EVAP system before the damper that would be raw fuel.
Any thoughts?
#3
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Just checked my TVV and it is all good. I have not noticed any fuel dripping or pooling under the truck. I have put a 3" lift in my truck and 33x12.5 on, but after the lift the mileage had maybe dropped by 1mpg, would going up 2" in tire diameter really affect the mileage that much? 200miles per tank is no fun
#6
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I get a solid 14mpg in town and 18.5 highway with my 3.0 and 32x11.50 ATs. That's without correcting for tire size difference, which is negligible IMO. 11 is a bit low, but close.
Andy
Andy
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#8
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The tires I had before said 32x11.5 but the actual measurements of the tire was 31" tall and about 11" wide, the BFG muds are a true 33x12.5. Even with overall diameter difference and speedo differences, I am at about 12mpg, which I think is terrible for the mods I have done. I was expecting maybe a 1-2mpg drop, that is why I am thinking that this fuel smell is my issue. It only began after I removed my intake plenum. Over fueling maybe? I have looked for a fuel leak, but found none. The truck still drives great.
#10
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I know the tires are going to kill mileage, it's the smell that is new. Only started smelling it after I took the mani off to replace the by-pass hose at the back. So i don't think a injector seal would fail right as i took my mani off. I was thinking I didn't hook a line back up or I crossed a vac line, but I have checked and re-checked everything. I am 100% positive that the lines to the side of the mani are hooked up correctly now. Any other ideas?
#16
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Location: Richmond , Va / Henrico Co.
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Bad Mileage
Have you checked your fuel lines and filter(Frame rail) in case something has hit them and damaged them and caused weeping that is barely leaking / a rusty line in need of replace - not enough to drip ?
#17
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Those would be things I would check if it just happened randomly, but this smell started as soon as I put my mani back on and fired up the truck.
#18
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you musta hit sumthing while reinstalling then.. take a good look for fuel leaks ill bet its leaking sumwhere and burning up. it must be. the only explanation for the smell.. Perhaps get a fuel pressure tester and see if it holds pressure?
#19
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Gas Smell
There is a line that leaves the Charcoal Cannister on the bottom of the can near the Firewall , its a vent line (at least on my '91) , supposed to be tucked in frame rail , think maybe that has been pulled out of its hole in frame or pulled loose from bottom of cannister ? , that would be right in the path of the passenger manifold , just a thought .
Other than that maybe it would have to be a small leak/weep somewhere close to the area you worked I would imagine since it started right then unless it is a coincedence .
Other than that maybe it would have to be a small leak/weep somewhere close to the area you worked I would imagine since it started right then unless it is a coincedence .
Last edited by n4ynu1010; 10-12-2007 at 04:58 AM.