3vz TERRIBLE gas mileage x2
02-05-2013, 07:00 PM
#42
Registered User
Thread Starter
wasn't too bad. Pretty much one of the hoses was completely off...well the cap was split pretty bad, and the duct tape that was underneath dried up and fell off haha! I just grabbed a vac. port plug off one of my spare carbs
02-06-2013, 07:26 AM
#43
Registered User
your first post said you had an auto but your signature says its a 5 speed. So pardon my confusion. Here is what I would do so take it with a grain of salt. I would change the o2 sensor since you said its bad anyway. Get a denso!! Ive heard nothing but complaints about the bosch ones on the 3vze. Then reset the computer and drive it. Still not happy?? set the timing to 15 degrees and open the afm up and adjust the fuel wheel 2 clicks lean. should drive like a champ and get 15-18 mpg.
https://www.yotatech.com/forums/f116...stment-203287/
https://www.yotatech.com/forums/f116...stment-203287/
02-06-2013, 11:32 AM
#44
Registered User
I wouldn't touch the AFM... it's not supposed to be opened. There's no instructions for even Toyota technicians so be forewarned: it may have bad long-term effects on the engine. Forcing the engine to run lean could make the engine run hotter than it is designed causing internal seals to fail faster.
A false lean code (vacuum leak that tricks the engine to increase fuel) would not drop to only 7-8 MPG. I had a bad valve allowing un-burnt oxygen in the system and my MPG's went from 17-18 to 14. You've got a lot of factors involved, basically you'll want to check ALL fuel and air systems. It takes time but every improvement and fix gets you a bit closer.
A false lean code (vacuum leak that tricks the engine to increase fuel) would not drop to only 7-8 MPG. I had a bad valve allowing un-burnt oxygen in the system and my MPG's went from 17-18 to 14. You've got a lot of factors involved, basically you'll want to check ALL fuel and air systems. It takes time but every improvement and fix gets you a bit closer.
02-06-2013, 03:33 PM
#45
Registered User
its your truck do with it as you please. Many people on here have played with the afm and have gotten good results for a long time. just make your own informed decisions
02-07-2013, 09:19 PM
#47
was a pretty big leak. Still have a funny idle, and rich smelling exhaust. I'll get a new 02, and lean out the afm 2 clicks, then see what happens.
02-07-2013, 11:22 PM
#48
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I had a really similar problem, replaced my spark plugs, spark wires, rotor, dis cap, and air filter but none of them fixed it, changed my fuel filter today and the fuel smell went away, weird idle went away and I noticed better fuel mileage. I never had any of those vacume leaks though, and if you have never changed your fuel filter you will be in for a whole lot of fun 
Last edited by mrbcyota92; 02-08-2013 at 09:22 AM.
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