3.0 L. engine troubles

Motor is still currently running with appx. 320,000 mi. on but all of a sudden i started getting 10 MPG. It doesn't matter if i'm babying it or if I redline every gear, still, 10 MPG.  where the do i start? MAFS? o2 sensors? ugh, its almost tax time. Should i just put a dang 4.0 TRD in it? I dont know.  

Oh yea, its an 1989 toyota pickup? would love to just fix the gas milage issue and wait for the motor to blow up.  

that motor sucks 3.0 are the worst motors ever if i was you i would yank it out and try to find a 3.4  

The 3.0 doesnt suck. Its not the best engine as far as power, but I have had hardly any problems out of mine. Is your check engine light on? You could take it and get it hooked to a computer to check for codes. Is the truck running bad or has it lost power?  

With 320K on a 3.0, it's kind of a miracle it's running at all  

The first thing would be to check the ECM for error codes.
Since your 89 is OBD-I, you don't use a code reader, it's a DIY procedure.
If you Search you can find how-to online.  
--------------------
seen in FOUR WHEELER magazine July 2006 and OFF-ROAD magazine Feb 2007

'84 4Runner SR5 -
ARBed 5.29s F&R, 4.7 & 2.28 t-cases, 2" drive train lift, AP hy-steer, BudBuilt x-member/skidplate, 36" TSLs, 30 spl Longs, Chevys, rears up front, winch, yada yada ...

'80 something Toy P/U -
Buick 231 V6, Holley 4 bbl, Weiand intake, Downey headers, TH350 L/U w/700R4 low gearset, dual tanks & batterys ...

89 4Runner SR5 -

yes the 3.0 does suck i know people that wont even have gone 200,000 miles and need a full rebuild the motors are crap and are pretty much worthless. I would take my 22re or a 22r over that motor any day.  

Well there is a little something called maintenance that you can do that goes a long way towards helping your engine run longer. I have 200,000 on mine and it was flipped on the interstate. Its all in how you take care of it. I also have a 4Runner with the 22RE in it and while it is a great motor, I like the power of the 3.0. Given the choice though I would say that the 3.4 is a far superior engine to any of the smaller motors.  

true the 3.4 is deffinately the better of the three i have a 88 toyota with a 22re in it and even after the 3.0 was rebuilt i would still have chosen my motor over it. it was well maintained never abused. just didnt have any balls in my opinion.  

i have an '81 pickup that had the 22r in it... 3 months after i bought it i was stuck on the side of the road wating for my friends to come get me. im gonna blame that on poor maintenance on the part of the previous owner. i had just changed the oil in my rig the week before its failure. my next rig is gonna be the 3.0 but only because no one in my area seems to have th 3.4 and im budget limited. never experienced the power of the 3.0 but im sure it will do fine as my daily driver. it might see Moab,Utah a few times but still im not worried.  
Knight

i just replaced my 3.0 with a remand.  got over 200k with my old eng and only replaced it cause i beat the every living crap out of my old one and hydrolocked it. it was running just fine afterwards but a new eng def. helped.  your poor mileage could be a stuck fuel inj, a bad air flow meter.  need to start doing some electrical diagnostics.  

check the fuel pressure.  

first off congratulations brother!!! second get the BG products that limbaugh always talks about. put the politics aside, that product is awesome. it'll clean out your whole system. i used it on my tacomaand got like 5mpg back. good luck with 500K you can do it