My car is idling entirely too fast. It drives itself and actually gets up to about 55 mph on it's own. I try to put it in park and the RPM's go up to 5-6. It happened before and they replaced the cruise control wire. It's scary. I can't believe this hasn't been recalled yet. If this has happened to me twice in one year, I can only imagine that others are having the same issue. Any advice???

tell what it does in drive. (selector)
how fast in drive,? MPH 5 ,10 ,20? what?
is the throttle pedal dead. RPM cannot be raised right foot in drive.?
or yuou race fast the engine, right foot but speed does not increase?
or speed does increase fast and RPM fast but transmission fails to go to 2nd gear.?
scan the car is step one,
is check engine lamp on ,? idle or moving

1. The testing has to start with the vehicle under 122 degrees F. Start the engine and idle for 2.5 minutes in Drive (auto) Neutral (MAN) A/C and rear defogger ON.

2. A/C OFF, accelerate to 55 MPH at 1/2 throttle and then 3 minutes of steady state cruise at 55 MPH.

3. Clutch engaged (MAN) no braking decelerate to 20 MPH.

4. Accelerate to 55-60 MPH at 3/4 throttle and 5 minutes of steady state cruise at 55-60 MPH.

5. Decelerate, no braking to end the drive cycle.

In some cases the Powertrain Control Module (PCM) will go into a logic lock not letting the readiness monitors run. Removing the battery cables and touching the two together will normally take care of the logic lock condition.

Catch?
cranks fast
starts every time.
idles fine hot or cold , or both? hot idle not too fast.
i race engine , in park and neutral, I can hit 3500 rpm easy, can you.
i release brakes, (brakes are not packed in ICE , are they?)
I select 1gear or reverse (A/T or m/t)
the car moves or dont move, which is it, my guess catch = no move at all.
I try to drive, i look at RPM and MPH
RPM moves up and MPH track.
track means they both move in a linear progression.
RPM rises and for all RPM increases MPH also increases.
does it?
if all that works then we have an engine power issue.
weak on hills?

check for leaking vacuum line. check the timing setting also check idle control senor

Can you tell if the engine speed increased ?
Something in the transmission could be slipping, or the tach could be faulty.

Here is the OBD2 emission system drive cycle test procedure.
Engine coolant temp must be below 70c (158f) before starting the engine for either the first or second trip
The fuel level should be less than 1/2 full
First trip:
Start engine, idle for at least 1.5 minutes
Drive 3 minutes, hold b/f schdl: 1.5-2.0 msec, selector lever "3rd" eng rpm 1,800-2,000 A/C switch:ON Hold the recommended b/f schdl range. Allow road speed to vary as necessary.
Drive at 55-65 mph for 1.5 min b/f schdl 2.0-3.2 msec, selector lever "5th" Engine rpm 2,200-3,000
IGN "off" for at least 10 seconds (not more than 5 min)
Dive at 50-60 mph for 3 minutes Selector lever "4th" keep engine speed above 3,000 rpm Allow speed to vary if necessary. Do not decelerate for more than 3 consecutive seconds. A/C switch ON.
Drive at a steady state cruise of 53-58mhp b/f schdl more than 1.8 msec selector lever "5th" eng rpm 2,400-2,600
Downshift to "4th" and decel more than 5 seconds without breaking, then idle for 1 minute.
Drive two minutes b/f schdl less than 2.0 msec Accelerate to 41 mph, decelerate to 34 mph, accelerate to 41mph. Do not completely release the accelerator. A/C switch off.
Idle 1 minute in park or neutral
Drive two minutes Steady state cruise at 31-44 mph. Selector lever "4th" A/C switch OFF. Hold the accelerator pedal as steady as possible. Allow speed to change if necessary.
End of first trip. Turn the key off the begin the second trip.
Second trip:
Start engine, idle for at least 1.5 minutes
Drive 3 minutes, hold b/f schdl: 1.5-2.0 msec, selector lever "3rd" eng rpm 1,800-2,000 A/C switch:ON Hold the recommended b/f schdl range. Allow road speed to vary as necessary.
Drive at 55-65 mph for 1.5 min b/f schdl 2.0-3.2 msec, selector lever "5th" Engine rpm 2,200-3,000
IGN "off" add four gallons of fuel
Dive at 50-60 mph for 3 minutes Selector lever "4th" keep engine speed above 3,000 rpm Allow speed to vary if necessary. Do not decelerate for more than 3 consecutive seconds. A/C switch ON.
Drive at a steady state cruise of 53-58mhp b/f schdl more than 1.8 msec selector lever "5th" eng rpm 2,400-2,600
Downshift to "4th" and decel more than 5 seconds without breaking, then idle for 1 minute.
Drive two minutes b/f schdl less than 2.0 msec Accelerate to 41 mph, decelerate to 34 mph, accelerate to 41mph. Do not completely release the accelerator. A/C switch off.
Idle 1 minute in park or neutral
Drive two minutes Steady state cruise at 31-44 mph. Selector lever "4th" A/C switch OFF. Hold the accelerator pedal as steady as possible. Allow speed to change if necessary. I especially like the part where they want you to add four gallons of fuel. Not three gallons, not five gallons, four gallons. Gotta love those Nissan engineers. ...and of course they state that if the trace is not followed exactly (i.e. you botch the acceleration/deceleration) you have to start all over again from scratch

Try changing sparks and wires

Throtle position motor faulty

car out of cruise control flutters or runs rough from 45 mph to 55 mph and once over 55 mph runs smooth. I notice from 45 to 55 the rpm guage moves with flutter or rough running engine. when i put in cruise control it smooths out.