Tacoma idling rough

I’ve got a 2009 Toyota Tacoma four-cylinder it’s still idling at about 7000 RPMs but it acts like it’s going to die when you’re moving it’s running just fine the gas mileage has went from about 25 miles to the gallon to about 10. Have replaced plugs. what could be causing this

 

check your idler pulley, is it not disengaging when you let go of the throttle? while driving, when you let go of the throttle, is the vehicle accelerating still?

 

Spark plug wires?? My 93 4cyl was doing same type of shenanigans. Replaced wires, problem solved.

 

7,000 RPM idle?

If the fuel mileage is that bad, I’d be looking at fuel trims and maf data.

 

No it don’t. It runs fine when accelerating. I did notice the belt was a bit loose. To me.

 

Thanks just had new packs and plugs put in didn’t help. Will check the wires

 

I assume you mean 700

Honestly. 1st thing i would do is disconnect the battery for a bit to reset any learned data. Then take it for a drive. It might idle funny for a bit as it relearns


I'd also be checking for codes.

 

Ok thanks. Had it checked for codes shows none. After I replaced the packs and plugs it is now making a clicking noise when I accelerate. Like something hitting the fan or a rod nocking. But only does it when I give it gas

 

dirty MAF or thottle blade many times will not throw a code. Just wonky accel./idling

 

That is my next step. After I replaced packs and plugs it has a clicking sound only when I Accelerate. Like rod nocking or like something hitting fan.

 

Again, if your mpg is that bad.
I’d look at fuel trims. Although, if the mpg is that bad and the trims are that far off, you should be getting a code.

If the knock started after the plugs and coils. Reinspect the work done. have some one rev the engine slightly while you inspect the coils and area around the coils.

 

Ok thanks

 

Thanks

 

Thanks. It is 700.

 

i just want to put on record that my suggestion for diagnosing the problem was based on 7000 RPM lol, i truly believed OP was stuck on full throttle

 

I knew he wasn’t….
The engine wouldn’t last long at that rpm.
But I had to point it out…..because that’s what the internet does.

 

i go with warm up engine then disconnect battery 10 min.re connect battery start dont touch the gas just idle 4-5 minutes idle gets lower and lower done

 

which spark plugs did you use?

'performance' plugs will cause that, and Amazon/ebay are well known for oem counterfeit plugs that won't work right either.

 

Go through the idle reset procedure any time you reconnect your battery. I definitely saw a difference after beginning to do it.

https://youtu.be/4xm-UpLO9tk?si=zpSseW69K3oq54gV