Hey guys,

I have a 93 3.slow that runs a little rich and gets 10.5-11 MPG.
I bought the truck about 6 monthes ago w 93k on it. It was neglected so I have replaced: O2 sensor, plugs,wires,cap,rotor,t-stat,radiator, cat and cat back. Power is good idle is smooth smells like unburned fuel more in the morning then any other time. Any ideas?

Thanks! Shaun

 

I have the same issues, no ideas

 

Have you checked your timing? Exhaust valve adjustment? Checked the adjustment on your TPS?(Per the FSM procedure) Checked the cold start injector timer switch?(Per the FSM procedure) Those are a few? Have you checked for codes? What sized tires do you have? Gear ratio?

K

 

5-speed or auto? If it's an auto, and a 4Runner......don't expect GREAT gas milage. I average 'bout 15.

 

Its a auto. Wasn't expexting great but 10.5 around town?!?! Tining is good I will check the other stuff listed. Does any one konw where i can find a link to the FSM that I don't have to download. ( this machine can't open the link stickied in the forum)

 

Throttle Body cleaning.....THROTTLE BODY CLEANING!!! I had the same issues burning rich and terrible mileage....Throttle body cleaning

 

Does it have factory size tires ?

 

yes it is factory equipped 31x10.5 and its an auto. but tires shouldn't make a difference for it running rich

 

I have a 5 speed 3.0 and I'm in the same situation..I cleaned out my Throttle Body. and put New NGK plugs and Wires in. and New Distributor cap.

Im running 30x9.50 with 4.30 Gears (stock)

And I run Fuel Injection Cleaner through it every oil change with 2x the Concentration.. Still 10 MPG.

Air Filter is fine. PSI on Tires is okay. no check engine light. Runs great. Brand new timing belt and water pump on there with 400 miles on it.
All fluids changed 2K ago
Spark Plugs/wires/cap put in 4K ago

 

Bad coolent temp sensor will cause it to run rich / bad milage. Cold start injector and timer also. Tune up.

 

Did you change the o2 sensor? It can be bad without throwing a code.

Also, check your brakes aren't sticking, Jack up both the front and rear and make sure you can spin the tires easily by hand, have someone press the brakes and release and check again.

I had same problem turned out my front calipers weren't releasing fully after braking.

And I get about 10-12 mpg right now with 35" tires, 4:10 gears, 5 speed on my 3vze. So you should definitely do better with 30" tires.

 

Yeaa Im going to replace my o2 sensor tomarrow...But yeaa I'll definately check my brakes because they almost feel like they're dragging a little bit when Im driving..how do I fix that? or do I have to get new brakes and calipers

 

I have a 93 pickup as well, same motor and the mileage is crap! 123,000 miles on it. It's never been abused, it was my brothers truck. I drive it to work and back, hardly anything else. I'm getting like 11 mpg and I don't do much stop/go driving. I had an 88 pickup with the same motor. I had put a jacobs high performance ignition on it, indexed the plugs and put good plug wires on it along with a k&n air filter. I could get about 16 in town and sometimes 21-22 on interstate.

I too am trying to figure out this problem. Going to change plugs tomorrow. I suspect one of my brakes may be dragging because I can tell the rear left drum is warped. Had an issue with the rear end where a shop fixed it but neglected to change pads for me. Grease kept oozing out and sticking things up, which warped my drum. So I'm going to go through the whole general tuneup, wires, plugs, fuel filter, etc and see how it goes. With gas at 3.43 I can't afford 11 mpg!

 

any of you guys every done a valve adjustment? im sure you guys are all over due for one

 

Sounds like a vacuum leak to me.

 

no valve adjustment yet. I inherited this truck after my brother passed and now I am slowly trying to go through all that needs done to it so I can keep it a while. I was lucky enough in my 88 with the 3vze to have had Toyota put a brand new motor in it back when the head gasket problems started showing up. It ran like a charm and got good mileage.

I have a mechanic who was one of the head mechanics at the ford dealership for probably 18 years, now runs his own shop from his house. He does most work for about $30 an hour. Timing belt change on my parents civic was $180 and that included any parts needed. I'll see what he'll charge to adjust the valves. All I know is I gotta do something too because I know this truck should get better than 11mpg.

 

I'd start with a compression test....

 

FWIW, the last 15k miles my 4runner averages 14.1 mpg. It's always 15-15.5 freeway and 10-12 around town. I feel like mine's in pretty good tune- brand new heads too.

 

i have an 88 as well but was never subject to the recall