Notices
86-95 Trucks & 4Runners 2nd/3rd gen pickups, and 1st/2nd gen 4Runners with IFS

bad mpg

Old Nov 3, 2009 | 10:24 AM
  #1  
pennywiserawker's Avatar
Thread Starter
Registered User
 
Joined: Dec 2007
Posts: 46
Likes: 0
From: maryland
Question bad mpg

Hey, so I recently did a complete 22RE rebuild and I cannot figure out why my mpg is only 14-16.You can smell how rich it is running. I've adjusted my timing, replaced the O2 sensor, my maf meter is fine, I changed the fuel filter,and adjusted my valves. Is there any computer problems I could come across? Please help!
Reply
Old Nov 3, 2009 | 11:04 AM
  #2  
90-3vzeslug's Avatar
Registered User
 
Joined: Sep 2009
Posts: 128
Likes: 0
From: RI
gotta let her break in man! She's still tighter than a bulls rectum in fly season! get some miles on her and she'll come right up in mpg
Reply
Old Nov 3, 2009 | 11:14 AM
  #3  
camo31_10.50's Avatar
Registered User
 
Joined: Aug 2007
Posts: 5,334
Likes: 4
From: Vian, OK
3vzslug is right...i got bad mileage with my rebuilt 22r until i put about 3,000 miles on it..now it runs A LOT stronger and gets about 20mpgs..
Reply
Old Nov 3, 2009 | 11:39 AM
  #4  
pennywiserawker's Avatar
Thread Starter
Registered User
 
Joined: Dec 2007
Posts: 46
Likes: 0
From: maryland
The thing is that I've already got at least 2500 miles on it and it got the same mileage when the motor wasn't rebuilt. The check engine light isn't on either. So that leads me to believe its some computer problem. All of my vac lines are good an in order as well.
Reply
Old Nov 3, 2009 | 11:46 AM
  #5  
pennywiserawker's Avatar
Thread Starter
Registered User
 
Joined: Dec 2007
Posts: 46
Likes: 0
From: maryland
I've never messed with the tps. Not sure how to either. And the plugs are new and gapped correctly.
Reply
Old Nov 3, 2009 | 11:47 AM
  #6  
camo31_10.50's Avatar
Registered User
 
Joined: Aug 2007
Posts: 5,334
Likes: 4
From: Vian, OK
can't the AFM be adjusted to run richer or leaner?...sorry i dont have a 22re so i dont know much about the EFI system
Reply
Old Nov 3, 2009 | 11:48 AM
  #7  
Junkers88's Avatar
Registered User
 
Joined: Mar 2008
Posts: 4,371
Likes: 6
From: Texas
Originally Posted by 90-3vzeslug
gotta let her break in man! She's still tighter than a bulls rectum in fly season!

Reply
Old Nov 3, 2009 | 12:03 PM
  #8  
abecedarian's Avatar
Registered User
 
Joined: Mar 2008
Posts: 12,723
Likes: 6
From: Temecula Valley, CA
Looks like some oversized tires on there. What are your gears?
Reply
Old Nov 3, 2009 | 01:33 PM
  #9  
pennywiserawker's Avatar
Thread Starter
Registered User
 
Joined: Dec 2007
Posts: 46
Likes: 0
From: maryland
in the picture i have 31 x 13.50 mickey thompson baja belted tires with the stock gears. but as of now i have 31 x 11 tires. im not sure what the stock gears are in that thing. ever since i bought it its gotten about 16 mpg. and it had over 300,000 miles on it. with everything ive done to it i would expect some sort of change but so far....nothing. what all does the tps do and how can i tell if its messed up or needs adjusted?
Reply
Old Nov 3, 2009 | 01:36 PM
  #10  
pennywiserawker's Avatar
Thread Starter
Registered User
 
Joined: Dec 2007
Posts: 46
Likes: 0
From: maryland
i guess my real question is how do i make my truck run leaner? any possible adjustment i can do the motor or computer?
Reply
Old Nov 3, 2009 | 01:49 PM
  #11  
03vrod's Avatar
Registered User
 
Joined: Sep 2009
Posts: 41
Likes: 0
From: NC
If you want to pick up some mileage.Make sure you have the 4.10 and run like a 225 or 235.Mine is a daily driver and pull the boat sometimes.I put 235 on mine and it's getting 24mpg mixed driving.I was going to put a diesel in it but I'm happy with it as it is for now
Reply
Old Nov 3, 2009 | 01:53 PM
  #12  
pennywiserawker's Avatar
Thread Starter
Registered User
 
Joined: Dec 2007
Posts: 46
Likes: 0
From: maryland
im not too worried about mileage. i just want to figure out why its running sooooo rich. the exhause smells like half burnt fuel. but it runs great. i feel like it would run even better when its leaner. thankyou for the advice though
Reply
Old Nov 3, 2009 | 01:54 PM
  #13  
abecedarian's Avatar
Registered User
 
Joined: Mar 2008
Posts: 12,723
Likes: 6
From: Temecula Valley, CA
TPS (throttle position sensor) tells the ECU if the throttle is closed and how far open the throttle is and the ECU can also calculate if you're stepping on the throttle to accelerate or letting off some to decelerate. The ECU uses the TPS, the air flow meter (AFM or VAFM) and the coolant temperature sensor (on the front of the intake manifold), as well as the oxygen sensor under certain conditions, to calculate how much fuel to inject as well as adjust timing appropriately. The O2 sensor is used by the ECU to monitor and correct the mixture so chances are that unless your O2 sensor is going bad you are running at the proper mixture given the current condition of your engine.

Unless your truck came with 31's from the factory, you are likely running gears that are inappropriate for 31's, probably 4:10's. With smaller gears, the engine uses more power to turn them and fight aerodynamics and therefore you will get less mileage than more appropriate gears such as 4.56 or maybe even 4.88's, though the latter may be too much but would feel good in the seat.

When the engine was rebuilt, were the cylinders bored over and larger pistons installed or were the existing pistons only re-ringed? Have you checked your compression lately?
Reply
Old Nov 3, 2009 | 01:54 PM
  #14  
pennywiserawker's Avatar
Thread Starter
Registered User
 
Joined: Dec 2007
Posts: 46
Likes: 0
From: maryland
and im pretty sure they are 4.10 gears
Reply
Old Nov 3, 2009 | 01:59 PM
  #15  
pennywiserawker's Avatar
Thread Starter
Registered User
 
Joined: Dec 2007
Posts: 46
Likes: 0
From: maryland
i put keith black 30 over pistons in it. i have not checked compression. i just want to know why its running rich. i dont feel that gears and tires would cause it to run rich. it almost smells like raw gas
Reply
Old Nov 3, 2009 | 02:00 PM
  #16  
abecedarian's Avatar
Registered User
 
Joined: Mar 2008
Posts: 12,723
Likes: 6
From: Temecula Valley, CA
Your cold start injector isn't spraying when it shouldnt, is it?
Reply
Old Nov 3, 2009 | 02:11 PM
  #17  
Magnusian's Avatar
Registered User
 
Joined: Oct 2009
Posts: 1,499
Likes: 1
From: Downtown Heckronto, Ontario, Soviet Canuckistan
Originally Posted by camo31"10.50"
can't the AFM be adjusted to run richer or leaner?...sorry i dont have a 22re so i dont know much about the EFI system
What's EFI? Eternally Failing Injection?

OP: What brand did you replace your O2 sensor with, some don't play nice? Maybe it's faulty and reporting wrong info to the ecu, if it thinks there is more O2 than there really is, wouldn't that give you a richer mix?

Then again I know nothing about 22REs as well, just a thought.
Reply
Old Nov 8, 2009 | 02:57 PM
  #18  
pennywiserawker's Avatar
Thread Starter
Registered User
 
Joined: Dec 2007
Posts: 46
Likes: 0
From: maryland
how would i go about adjusting my tps?
Reply
Old Nov 8, 2009 | 03:08 PM
  #19  
DupermanDave's Avatar
Registered User
 
Joined: Aug 2008
Posts: 1,758
Likes: 3
From: Northern Colorado :-(
You can make it run leaner by adjusting the gear thingy in the VAFM. But I wouldn't recommend it. The computer should be doing all the work to get you the best performance.
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
krimsonone
86-95 Trucks & 4Runners
8
Sep 13, 2024 09:33 AM
TACOJO
95.5-2004 Tacomas & 96-2002 4Runners
8
Nov 27, 2015 05:26 PM
konah
Early Land Cruisers
3
Jul 30, 2015 02:08 PM
coffey50
Offroad Tech
17
Jul 28, 2015 10:55 AM


Thread Tools
Search this Thread

All times are GMT -8. The time now is 01:29 PM.