Fast Idle

Purchased used 2021 TRD, only 5000 kms or 3000 miles on odometer.... pet peeve... fast idle stays on for 12 to 15 minutes .... Toyota says thats normal. Anyone out there know how to adjust fast idle to come off in 3 minutes???

 

That's a long time

Even when it in the 20's for me, mine doesn't idle fast that long

Idk how to adjust it though

 

It was around 40 degrees this morning and I let the truck idle until it kicked off fast idle and it took 13 minutes. At 90 degree weather it will kick off fast idle after 10 minutes. This can’t be normal!!

 

What do you call fast idle?

Idle speed is mainly based on coolant temp and a couple other inputs such as A/C being on or off, electrical load, power steering pressure, and wheather or not the transmission is in gear.

It's normal for idle speed to start at 1500-1800 RPM on a cold start and gradually come down to 500-700 as the engine reaches operating temperature.

An idling engine will also warm up more slowly than one under load especially in cold weather.

A faulty thermostat can cause the engine to warm up more slowly than it should and/or not reach operating temperature at all in cold weather, I wouldn't expect one to be bad on a new truck but I suppose it's possible.

Does your temperature gauge come up to normal in a reasonable amount of time?

There is no way to change idle speed other than tuning, it is completely computer controlled based on programming and inputs.

 

Thanks for the reply Dm93. On a cold start it jumps to 1200 rpm and after about 5 minutes drops to 1000 rpm. When temperature gauge reaches normal operating temperature the the rpm’s drop to about 600 which happens after 12 minutes. I’ve owned a few trucks in the past and have never had an engine warm up so slow.

 

I haven't driven a 3rd gen so I can't say whether it's normal for them to warm up that slow or not but it does seem kind of long, do you know anyone else with a 3rd gen with the same engine that you could compare it to?

 

I actually stopped in to two Toyota dealers and asked their technicians about the fast idle and one said if no dash alarm or notification appears then that’s normal and the other said that’s normal. The truck is under warranty but they won’t check my concern unless a dash alarm appears. I think it’s to slow to warm up.

 

Like I said without comparing it with another truck I don't know if it's normal or not, some engines are slower to warm up than others.
I would expect it to throw an insufficent coolant temp (P0128) code if the thermostat was stuck open.
My 4.0L truck seems to warm up a little slower than some other vehicles I've driven but I don't think it takes that long (I've never timed it)

 

Seems fine to me, just run it harder after the start and it’ll warm up faster.

 

That sounds logical Kramer.

 

I haven't timed mine but I'd estimate the same general experience, and it's defiantly fast. I cannot say if it's 1200 or 1400, but thats nearly double what's typical with a lot of cars I've owned.

What's worse about this issue is that if I only let it run for 30 seconds or so, pull it into Drive it speeds up and jumps forward to the point of taking up full suspension and driveline play. (This happens intermittently, and the fast idle is only on cold start). If I were to let off the brake simultaneously it would take off and that to me is not OK. I only have about 600 miles and I have not contacted the dealership, but I plan to. I haven't been able to see exactly what the idle speed jump is but it looks like closer to 1600.

Mike

 

Hey Mike, the Toyota Dealership in my area said “that’s normal “ ... my truck has the same issues as yours does. I’m looking for a tech that might know a fix for the fast idle staying high issue.... there could be an adjustment or a way to dis-connect the fast idle. It may affect warranty but not concerned about this.

 

This is normal operation. I didn't design the truck but as a Red Seal mechanic I've noticed aluminum blocked engines such as ours tend to loose heat faster than it makes it. Idling these engines wouldn't warm them up like older vehicles. Best thing for them is to start them, clean off your snow/plug your phone in and get your music going then drive away. As long as the engine has ran long enough to smooth out and the oil pressure light is out then you're good to go. Take it easy till you're up to temp mind you but, modern cars don't warm up in the cold from idling

 

Hi Nolan, What's the deal with the RPM jump when putting it into gear. Is that just the slip of the transmission engagement, or is the ECM intentionally raising the RPM?

Glad to hear this directly from a Toyota tech.

Thank you
Mike

 

The fast idle is a warmup strategy, all fuel injected engines have a cold start high idle. Manufacturers want to get the engine up to operating temp as quickly as possible as well as the getting the catyletic converters in the exhaust up to temp so they function properly, it's mostly about emissions plus a cold engine uses alot more fuel than an engine at operating temp.

Here is the stock desired idle/temp tables for the 4.0l that @JustDSM posted in the HPTuners thread, IDK how they compare to the 3.5l maybe he will chime in with them. I'd be curious how they compare.

Park/Neutral


In gear

That's typically part of the anti-stall strategy, whenever the PCM gets a load input such as the transmission being put into gear or A/C compressor turning on it opens the throttle slightly in anticipation of said load, once the engine speed stabilizes it goes back to the desired idle lookup tables for current conditions.

 

Just to Clarify i'm actually not a Toyota Tech. I actually am a Gm Tech But the jump in rpm is prolly what is known as "morning sickness" which is essentially when everything is so cold the metals are a little more contracted than normal so as DM93 was saying, the computer is idling up to compensate for the load of it being in gear but with everything a little more contracted there is a little more transmission fluid slippage / the fluid is cold and not as quick to fill and pressurize the clutches to engage the gear so you get a little bit of a flare between the time you place it in gear and the gear actually engaging

 

I have a 2022 V6 Tacoma with a tow package that should include the better alternator. I know that the idle RPM will change based on electrical load. But what are the limitations of that idle change? If I hook up a heavy duty inverter to the battery, how many watts can I pull before the truck starts idling higher and using more gas and how many watts can I pull safely if I feel comfortable consuming more gas

 

as a critical thinker and somebody who’s owned a Subaru, replace your thermostat, flush your coolant all that is connected to the thermostat opening or closing procedure. I don’t even know what I’m talking about

 

Does anybody know if there's a fast idle switch for Toyota tacomas or if anybody knows how to program that? I can't seem to find any kits on sale for my V6 2022 TRD Tacoma stick shift