Extremely low idle

[SpeedoJosh]

My 4runner has an extremely low idle. When I start it, it drops to below the first big tik on the tachometer, which I assume is 500. It stays there without surging or anything, but just seems way too low. At a light, I can barely hear it running. When in drive I can let off the brake and the truck won't move or inch forward. On a hill, the truck will roll backwards when in drive until I hit the brake.

Other then that, the truck runs fine. Every once and a while if I have to give it lots of gas to get up a hill it will mis, but I've ran the code and searched the forum. I'm 99% sure it's the fuel injector issue I read multiple threads about. Code clears itself shortly after. I'll get around to changing that during Christmas break, but I don't think it's causing the low idle.

Any advice?

 

[dhalsey]

My 4runner has an extremely low idle. When I start it, it drops to below the first big tik on the tachometer, which I assume is 500. It stays there without surging or anything, but just seems way too low. At a light, I can barely hear it running. When in drive I can let off the brake and the truck won't move or inch forward. On a hill, the truck will roll backwards when in drive until I hit the brake.

Other then that, the truck runs fine. Every once and a while if I have to give it lots of gas to get up a hill it will mis, but I've ran the code and searched the forum. I'm 99% sure it's the fuel injector issue I read multiple threads about. Code clears itself shortly after. I'll get around to changing that during Christmas break, but I don't think it's causing the low idle.

Any advice?

Search for seafoam treatments. After you have seafoamed put a small bottle of lucus fuel treatment in every gas tank.

 

[SpeedoJosh]

Thanks for the tip. I assume that's for the misfire. It's been to the dealer and they've done their fuel system clean on it. I'll try running a handful of cleaners through there before I remove the injector.


Any insight to the low idle?

 

[awpsome]

Insight to your low idle, i had the same issue before and it was the IAC acting up.
Extremely dirty and because of this, it would not be able to open and close.
The IAC is attached to the bottom of your throttle body and if you plan on removing it to clean it, BUY THE GASKET first.
I learned from experience, took it apart to clean the gasket has been in there forever and has stretched out that once i removed it, it would not go back to its original place.

Its also a gasket that keeps your coolant separate from your air so its quite important to not and try to shove the old one back in.

Truck was down for a day, but if you have the gasket ready, removing then cleaning then putting it back together should be no more then 30 minutes to an hour.

After cleaning and flushing it throttle body cleaner if you still have issues your IAC might be going bad.
They are not cheap to replace.

 

[Jc12]

i had similar issues but my truck threw a code - it was the air fuel meter (02 sensor). The truck would idle so low it would stall out on occasion. Have you tried resetting the ECU?

 

[SpeedoJosh]

Haven't tried anything yet, wanted to check here before I dove in. I'll check the IAC to see how dirty it is. Thanks for the tip.

Haven't tried resetting the ECU. Just disconnect the battery correct?

 

[Jon]

Reset ECU by disconnecting NEG terminal for 5min.

IAC - Idle Air Control

If blocked you will have a low idle due to starvation while the throttle body is closed. The IAC is a bypass and will get clogged over time. Mine was pretty bad when I bought mine at 330k but now I remove and clean the throttle body prbably once a year just to keep it running as efficient as possible. Just dig for the thread. :thumb:

As for the miss... what altitude are you at and what grade fuel are you running?

Have you done new plugs and wires?

Fuel filter?

How's that air filter?

Vacuum leaks?