1992 FJ80 Gas Mileage decreasing

[snp32]

I bought a '92 Land Cruiser w/ 130k miles. For the first year i was getting about 11mpg combined highway/in town. Since then I've sloughed off considerable weight, removing swing-out tailgate etc., went from super aggressive Mud Terrain tires to goodrich all-terrain Ko2s, changed plugs, filters etc. but my mileage keeps going in the wrong direction. I'm now maxing out at 9mpg with the same driving behavior etc. Not sure if any of the above would have made much of a difference but I've lost 2mpg. :-( Any ideas?

 

[Marvelicious]

Does "etc" include looking for air leaks on the intake side?

 

[snp32]

Ooooh, no. Project for the weekend! I guess I need to get a smoke machine.

 

[Marco Lau]

you can visually inspect the intake tube by removing it and flex it and see. No need for a smoke machine really. Also have you change your O2 sensors?
I would start with those. Having a cracked intake tube would most likely result in rough idles...

 

[snp32]

Yeah, I guess, in the end, just replacing it would be less $$ than a smoke machine. There goes that dream...
Anyway, thanks for the tips! Will check back in with progress after the weekend.

 

[Marvelicious]

Yeah, I guess, in the end, just replacing it would be less $$ than a smoke machine. There goes that dream...
Anyway, thanks for the tips! Will check back in with progress after the weekend.

There are some DIY plans around for smoke machines involving a soldering iron and some kind of vessel. Haven't tried it myself, but I may in the future.

 

[jjdeneen918]

I’ve got a discussion going on this matter.

I’ve already replaced both O2 sensors, with no avail.

Currently at the shop, awaiting a diagnosis.

Under 8 MPG

Last fill up was an average of 7.7 MPG. Siiting at Costco now to fill up again. 164 miles on the trip ODO. Expecting similar results. Mixed town/highway milage. ‘96 LX450. Wits End turbo kit. EGR disabled since new HG installed a few years back. Had injectors cleaned/mapped them...

forum.ih8mud.com

 

[Devils Paw 80]

I bought a '92 Land Cruiser w/ 130k miles. For the first year i was getting about 11mpg combined highway/in town. Since then I've sloughed off considerable weight, removing swing-out tailgate etc., went from super aggressive Mud Terrain tires to goodrich all-terrain Ko2s, changed plugs, filters etc. but my mileage keeps going in the wrong direction. I'm now maxing out at 9mpg with the same driving behavior etc. Not sure if any of the above would have made much of a difference but I've lost 2mpg. :-( Any ideas?

Bad injectors?

 

[jjdeneen918]

Hopefully not injectors.

I sent them to RC Engineering several years back when I did the HG & turbo install.