I've never had mine rev to 3,000, but I do know cars these days will rev up when in park on a cold start to raise catalytic temps faster.
An emmissions thing.
Something did seem to get hung up by a very small amount, it wouldn't take much to do that.
The amount of effort it takes to free rev to 3,000 vs in drive is a significant difference.

 

One thing about this supposed High Rev thing..... on an unloaded engine, revs can increase easily. With any load at all, it'd be down at or near 'normal'. That way, while in gear, there would be no vehicle acceleration. Add Foot On Brake, and there wouldn't be any movement at all. Now I'm comparing to those old Toyota Law Suits where Sudden Acceleration supposedly caused collisions.

 

Good point -- but it shouldn't happen. So, working to figure it out. Going to inspect and clean TB and related areas, and do a vehicle reset with SDD. Will advise back.

 

good to know, i really appreciate the detailed information. i do think you should clean the MAF and probably even the O2 sensors.

however, that is not unintended acceleration, and as far the ECM knows you are asking it to do what it's doing: you've started the car and it is raising revs at startup for exactly that purpose (and maybe other stuff, i don't know). it's just reading something wrong, and so revs are twice as high as they should be, yeah. but you've told it to begin the startup procedure, and it isn't accelerating. acceleration is the rate of change of velocity. your velocity is 0 and your acceleration is 0, and you cannot change that without putting your foot on the brake (which you said you did not do, they're nowhere near the pedals) and shifting the transmission into drive or reverse (obviously you did not do that).

if you can safely do so, please park the car where you could lurch forward, and the next time you cold start the car keep your foot on the brake, and when it reaches 3k revs, put the transmission in D, carefully let go of the brake, and then put your foot back on the brake again as immediately as you see fit. observe whether it actually runs beyond 3k (i would not worry too much about damage, all ICEs damage themselves just the same at startup), observe whether the transmission goes from park into neutral as you turn the knob to D (hmm, never even looked. do you guys have a knob? a stick?), observe if it is chomping at the bit to get moving as you ease off the brake. and goes without saying if you experience any "runaway" simply do what you need to do: slam back down on the brake pedal, shift to N, or press start/stop until the engine cuts out. that would find unintended acceleration or a malfunctioning throttle input!

edit: it stands to reason you might also start the car with a blip of the brake pedal and then foot off, but thereafter if you observe the revs go up, slowly-but-not-too-slowly depress the brake all the way from "lightly" to "emergency stop" and see if it drops to idle. and if not, hold the brake there and start to shift to D, but don't go all the way, then go back to P or to N (and then shut the engine off if necessary). you should be able to trick the transmission to shift to neutral with the brake pedal down at some point in that process and the engine should drop to idle in anticipation of a shift. with clean sensors that actually may not be throttle related but some other ECM problem that "washes out" the throttle position data with the warm-up procedure, if that makes any sense.

 

Issue appears to be a badly attached throttle body intake. I found it was crimped at the bottom of the TB, out of sight. Solid vacuum leak, but not enough to kill the engine, as, say an open oil cap would. Also cleaned the throttle body (filthy) and the MAF (also filthy). Recommend TB cleaning to anyone who has the knowledge to do it. Not sure if the TB condition also contributed to the unintended acceleration.

Cold start now increases to an acceptable 1200-1500, with expected drop to normal idle.

Also identified one vacuum leak with a smoke test at the base of the oil filler tube, and part on order. The o-ring is likely rotted.

Plan is to fix this obvious one, then run a more aggressive smoke test at a higher pressure to get others.

Just a comment: I'm finding a lot of useful info on the X100 boards. Lots of engine things that appear on 15-20 year old X100's, such as vacuum leaks and degrading sensors will also appear on the relevant X150's as they age. Good place to look for ideas.

Best, Panthera

 

Thank you for the report back, and not leaving us hanging. o/

 

Good to know it was an actual Problem and not a foot issue. Also that it was a very isolated issue with the OPs vehicle specifically.
Course others may benefit by this thread at a later time.

 

indeed i'm building a padded wall in my garage for when the day comes.