2005 4.0 Toyota Tacoma Idle Issues That 4 shops can't figure out

Do this
Pull the ECU fuse for 5 mins. Put it back in.

Then start the truck up and let it idle for 10 minutes

Turn the truck off.
Wait a few minutes then start truck again
Report back to us

 

This has already been done at least a dozen times.

 

Okie dokie
How far has the truck been driven in this condition, some say you may need to put 100 miles on it for it to get it senses back

 

For what it’s worth, we had a Ford that had a problem similar. Switch leaked through and was wicking down to ecu. Replaced, fixed problem. Been a while, so details lacking, but do know that happened.

 

that could be something. If messing with the pressure switch circuit affects the idle I'd continue looking in that direction.

The p/s pressure switch tells the idle to bump up when it sees you turning the steering wheel at low speeds and needing assist. Sounds like they already tries a new switch. If the wiring to the switch is pinched or shorted it could mistakenly tell the pcm to raise the idle all the time

 

I'm thinking something along this. Alternators can get stuck on, overcharging or stuck off, not charging. Also, with a dead battery, the alternator is working harder than usual to try to charge it up. I'd check the alternator output to see what it's doing, just to rule it out as a problem. It could be stuck on, and overcharging the crap out of your new battery. There should be a big wire attached to the alternator. Look to see if it's melted.

 

I am thinking same, possibly an ecu issue. Maybe get a used one if they can be re-flashed for your vehicle and see if that fixes things.

 

is this a 6cyl or 4cyl?

Never mind, I see the thread title

 

it was previously mentioned that when the pressure sensor for the power steering is disconnected, the idle goes down, and it was also mentioned that when the computer gets a signal that the pressure goes up, it bumps up the idle.

if there is no short in the PS pressure sensor wires, and the sensor is "good" ( should actually be tested, even new pars can be broken ) then perhaps you should have the power steering system pressure tested. I *could* be over pressurized

 

Perhaps the flow control valve is "fudged" causing the system to be at a high pressure all the time.

 

this is from the FSM,


do you know if those systems have been checked yet?

 

That "ecm power source" comes to mind. Maybe one of the smaller pcm /EFI fuses is blown and nobody noticed

 

was this issue resolved? im experiencing the same issue...