I recently bought a 1992 4Runner with a 3.0 in it
since I bought it’s been having number of things wrong with it. first off it’s been having really bad fuel milage filling up tank every three days. also over drive kicks on when it’s a hot day or I have to drive for quiet a while for it to kickon. One other thing I takes a while for it to warm up to normal operating temperature.
any fixes?

 

First thing to do is install a genuine Toyota thermostat

 

Where could I get one?

 

From any Toyota dealer, in person or online.
I see many for sale on Ebay and Amazon.
The correct part number is>>>> 90916-03079
Do not buy a knock-off, get the Genuine Toyota part.

 

What about the fuel mileage issue what do you suggest

 

The thermostat may, at least partially, address the mileage issue.
A cold running engine will often not let the ECU go into closed loop where the O2 sensor controls fuel mixture.

 

The correct part number is 90916-03079
Do not buy a knock-off Get the Genuine Toyota part.

 

Will the thermostat cause the exhaust fumes smell Rich in gas when idling

 

My 3.0 4runner smells rich while idling and it gets 18 to 20 MPG.

 

What other upgrades should I consider getting done on the 4runner?

 

One thing at a time.
See if proper engine temp alleviates any of your issues.
That said, a plug, plug wire, and ignition component tune-up with verification of correct ignition timing, is often in order.
Genuine factory parts are always best.

 

Thank you for the help!!

 

beyond what millball has suggested, what IS your fuel mileage? telling us that it only goes 3 days to fill the tank does nothing. i regularly fill my tank every three days, but that's because i've put 320 to 350 miles on my 4runner; my runners get 18 and 22 mpg for averages, respectively. both are 22re/5-speed.

 

Well I just drive to work and back from work(10 miles far) and every now then I pick up my mom or go to the store but normally it’s stays at the house
I found out that it has a egr delete and they missed some steps that I corrected.
normally when I go to work at 50-70mph it stays between 3,500-4,500 rpm’s
but when I took a trip to a town 20 mins from where I’m located and the temperature was 85°f outside. I was driving back the overdrive kicked on I was cruising at 70 mph at 2,500-3,000 rpm’s
when I bought the 4runner the guy that sold me it told me the overdrive only kicks on when it’s hot outside
also if I don’t let the 4 runner warm up for 5 minutes before leaving the house to go to work it won’t go into 2nd gear

 

so you get 60 miles on a tank? yeah, your engine has problems, that's around 4 mpg.

 

I ordered the oem thermostat like millball mentioned.i seen youtube video of a guy saying it’s clog where the ect is located or the ect sensor is bad cause he had same problems im having.

 

That was going to work this morning

 

One thing to consider: The temp gauges on the instrument cluster are notoriously inaccurate. It's indicating 1/4 deflection. That could be anything up to 195° F. It might be a good idea to get a remote temperature gauge and check the temp of the water going in the top of the radiator, or at the thermostat housing.
If the temperature gauge is accurate, that could explain the RPM/Speed. The transmission uses temp to set the gear vs the speed you're going. If the engine stays too cool to set the gear correctly, that might explain your lousy mileage.
Also, is your transmission fluid in good shape? The right color, no burnt smell, and so forth? No pink milkshake, or evidence of transmission fluid go
What about your coolant? Is it in good shape, the correct, 50/50 mix, and so on?
Is your radiator cap keeping the pressure correct once the engine is good and warmed up? About 12-13 PSI? You can get a pressure tester for the radiator cap, and the radiator, from most auto part stores that have a tool borrowing service.

 

Right now it’s in the shop but as soon as it’s out I get on it and check