Throttle Surging. 2017 V6 TRD 4X4 Off Road package 31,500 miles (aprox)

Was backing my Taco into the garage. The idle speed would go up without foot pedal input. Holding the truck with the brakes, the idle would settle down. As soon as I lightened up on the brakes and the truck began to move the throttle would react. Idling at around 750, as soon as the truck moved it would jump to 1K and I'd have to apply more brake, thus stopping the truck and the idle would fall back down.

Air filter is new. Truck has 31K5 miles. All stock, no mods to engine.

What can cause surge?
How can it be addressed?
Could it be a dirty sensor?

 

pinning the steering to one side usually causes the rpm to climb. cold engine will act a little cranky too.

 

Perfectly normal for this 3rd gen truck. Adjust, overcome and adapt

 

Power steering pump (were you steering) and ac compressor. Both will change idle rpm.

 

Actually I hadn't thought of the compressor. Only noticed that it would idle lower when not moving but as soon as the tires began to rotate the RPM's would pop up a bit. Made it difficult to move the truck back slightly. Every time I moved back it moved a foot further than I wanted. Of course I had to release some brake pressure to allow the truck to move, but I thought it was odd that out of nowhere the truck started acting like it wanted to leap out from under me every time I tried to slightly move the truck.

 

Electric steer. No pump.

 

It's not Friday yet

 

Really.

 

Discovered my profile had my 08 Taco which was 4 cylinder manual transmission. Traded it in for the 17 brand new off the lot.

 

Anything related to idle, first clean the throttle body with throttle body cleaner.

No need to spray it inside or around. Just wipe the blade inside and out with clean rags moistened with the cleaner until the outer edges of the circular blade is shiny clean. You will notice the edges are likely black bedore you start.

A 15 minute job, and resolves most idle issues. The throttle body is that sensitive.

Will not fix a surge issue but will make your truck idle like new. You will be very happy.

Minor surges on idle can occur with the third gens and no cause for concern unless the truck is running like crap.

As others have noted, the cleaning cycle causes some of that, running AC does the same, or just having the vents on defrost setting but no AC. All of those are normal.

 

Do you like to start and go, immediately?
They like to finish the "start up cycle" (if that's what you call it) and idle down before taking off.

 

Again, power steering or AC compressor

 

Mainly, it's the power steering. Turn the wheel and it wants to lunge. Getting the tune (kdmax), that eliminated most of the issues

 

My 2020 does the same thing randomly. Mostly when backing into my garage for some reason. Just gotta keep foot on brake to control it.

 

Clean your TPS, and check for vacuum leaks.

 

I get this every now and then in the winter time. RPMs just surge up and down while parked

 

While parked? What is the ventilation set to at the time it happens, and for how long will it surge up and down, and by how much?

For example, if it revs say between 500 and 900 rpm, and repeats over and over for more than 10 seconds, clean your throttle body plate. The example I give is a clear indication you need to clean it. It may not even do the revving every time, but when stopped the idle should be very steady, other than when the compressor kicks in on AC or defrost setting and temporarily raises the rpms.

Speaking from experience. Mine did crazy fluctuations and got progressively worse for a few months.

In the 2 months since cleaning, it has not done it a single time. Previously it was doing it every second stop or so, revving between 500 and 800rpm for 3-15 seconds.

Once when parked, it revved between 500 and 1000 rpm non stop for a full minute then returned to normal. Like a carbureted vehicle running too rich and wanting to stall.

That was it, it was time to stop being lazy and clean the throttle body plate.

My idle now under all scenarios, hot, cold, parked, stopped in drive at a light, pushed hard in the bush or driven cold, and the idle is bang on and never fluctuates even a single percent. I had previously changed the plugs, new air filter, new MAF valve. Those all made minor performance improvements, but had zero impact on the idle.

Wish I had cleaned the throttle body first…

 

My issue was surging in 70+ temps on cold start. If I put it in gear without letting the truck complete the “start up cycle” (also don’t know if that’s what it’s called but I like it) it would surge until I gave it some throttle. Wasn’t steering related and I didn’t think to rule out hvac settings before I threw the works at the issue:
Throttle body, MAF sensor, injector cleaner fuel treatment, high octane for 3 tanks.
One or all of those fixed my issue.

 

Yea while parked, only occurs in the winter when the defrost cycle is on. Yea it surges between 500-900 and can last around 30 seconds but I haven’t gotten the chance to actually time it.