stuck aceleration

[Pedro Fontes]

yeah

 

[Handy Andy]

Went to the site, but video is no longer available.

But we do encounter problems in fleet cars at times much like the symptoms you have.

Higher idle speeds and doesn't seem to want to "settle down"

Can be caused by several events - much like what Toyota encountered when it had the pedal stuck condition - only to find out it was some operator error - floor mats and debris - while other incidents were from the recoil mechanism that pulls the pedal back up from the floor - over-spun and the substrate or composition of the rheostat (that variable potentiometer used to determine throttle angle) didn't have a redundant check to validate and prevent the system from over-revving due to the overthrow of the wiper arm in that rheostat sending a value that made the pedal look like it got punched to the floor or worse, the arm and composition failed to give a good clean response to throttle to angle changes so the system hung up and stayed at a value until the pedal can be re-zeroed out.

This "zero-out" normally would occur on start up and should also be temperature compensated and the re-calibration has to take place when the engine is first started not while your in gear and driving. This type of predicament, and no way to keep control of the vehicle when you have to shut off the engine to restart it - is what makes this dangerous.

The system needs to have the Accelerator pedal position sensor possibly replaced too so the re-calibration process it goes thru, it sees a new idle end-zero point to reference to - crappy construction and overzealous springs be (gosh) Darned...on start up and stays stable. So a new pedal may be needed too.

So check your floor mats, not curling under - make sure the wiring to the APP (Accelerator Pedal Position) Sensor is clean and no nicks and it's connector is properly seated. Might need to make an ohmic check - the grounds also need to be checked at that thing - for there may be a grounding bond point behind it at the firewall to tie a bunch of ground wires returns together to a bolt by and behind the brake pedal. IF the bolt has rusted or the wires are backing out of it - this make the condition serious.

So to me this may be just some floor mats in the way onto a more serious problem of a Ground point issue and loose wires causing the pedal to show differences in references (supply to ground relationship to where the pedal is and where the system thinks it should be)- which the system can think your lazy on the pedal while your not even touching it.

 

[Handy Andy]

Considering what you're up against - the Pedal sends two signals - one to the PCM while the other goes to the Instrument cluster.

IF one or both don't agree - this can set a check engine light - it doesn't seem to - how are the I/M monitors? Anything showing up in Engine or Emission? As NOT READY?

The issue around "Engine" being the problem, seems the Idle is coming up to compensate for something it's sensing - so does it have some kind of vacuum leak? By symptom is what I see in your current vid might be this problem - since the Throttle body been checked - does the Manifold have a crack in it? Might need to squirt-squirt of a carb cleaner around the manifold and it's mating surface on the cylinder head and see if Idle speed changes - this may be a vacuum leak but from where? Not sure...else, PCV valve seal gone bad, it's holder got cracked, or the IMAPT (that MAP sensor) on the intake manifold - does it still have it's seal intact?

 

[Handy Andy]

Had another thought - this deals with observation of the throttle plate.

You own a 2015 so it should have the "Single sensor - multi function" Intake Manifold Air Pressure Temperature" IMAPT sensor - which brings up is it acting up and has dirt or oil sludge?

Because if it's single sensor - this makes it easier to just start the car and let it idle remove the snorkel and observe that throttle plate.

For if it's moving to open for that 1500RPM then there's an issue with the communication to the throttle plate or is there a problem with one set of valves or both, that being; of the VVT solenoids holding open and letting oil pressure move the advance chambers to raise the RPM to higher advance? (That being due to the advance of the valve timing due to the solenoids letting oil move the advance which the engine will see and adjust the idle speed to accommodate it)

The "dirty" part is the IMAPT letting this all happen due to the ability to sense the changes are gradual and not instantaneous letting the system think there's emission issues (Those I/M monitors) so it lets the RPM rise and fall - acting like it is "seeking".

The whole premise of this post if to ask if you have any means of measuring the vacuum Hg psi or in inches, IT's so you can see if a leak is occurring then it's easier to know the problem - for if the Instrument Cluster is getting one reading - what does the PCM see? IF the two agree - then the issue is in the mechanical part of this (Vacuum leak or advance issue causing idle up condition) versus an erroneous electrical signal getting sent to one or the other causing this.

Which is why the PCM and the Instrument Cluster grounds come up - if they are different, then the signal grounds are not equal, so current flows from one to the other thru the system generating a power flow floating above ground - not actual signal ground - so it can;t find or know if the throttle is really at idle or somewhere in-between.