Out of control in a Disco II

[troverman]

Anyone ever had a problem where you are going along at, say, 55mph and ease up on the gas to go around a corner or down a hill, etc, and the speed doesn't let up? And then, (it happened to me this morning) you kick it down to around 3,000 RPM to go up a hill, let off, and its like the accelerator pedal is stuck to the floor because you are flying 75mph in a 45 zone, and the pedal is not stuck, and the brakes aren't strong enough to slow down the truck? So you are forced to put it into neutral and pull off, and the engine immediately and continuously revs at 5,000 RPM or more, so you immediately shut it off! The gas pedal was not stuck, and the cables moved freely under the hood, and upon restarting, it restarted normally and idle fine, so you keep going, but in a few miles it is doing it again, sometimes holding at around 2200 RPM and maintaining 50 / 55 mph for you (like cruise control is on, but of course it is not) and sometimes just revving to a much higher amount, to where you will lose control because the brakes can't hold back the engine and you're going way too fast, so neutral, off, etc... It all made for a very unpleasant ride this morning, and unsafe.

What's the problem?? Throttle Position Sensor?

[02disco2]

Jesus.. This may be a stupid question, or two.. but:

1) you sure your cruise isn't engaged?
2) did you have the abs modulator recall completed on your truck?

[Disco Mike]

Simple things to look at, carpet jammed up around the gas pedal or check both of the throttle cables at the thrpttle body. The one other area would be the inside of the throttle body, if it is really carboned up it will cause the throttle body plate to stick open.
Mike

[troverman]

Cruise definitely NOT engaged, master switch off, would not use it on this kind of road (winding, along Connecticut River.) Plus, the heavy braking done to try to get the car to slow down would have disengaged it anyway. Also, nothing under / around the pedals! I have the factory rubber mats, no trash on the floor whatsoever! I actually reached down and physically pulled up on the accelerator pedal--it was all the way up and the engine kept accelerating! Under the hood, both cables were fully out--no throttle. With the car off, and a helper fully depressing and releasing the pedal from inside the car, the cable fully opened and released. The cruise cable was also free. If when pushing the pedal the throttle fully opened and released with no hangups, I don't think the throttle body could be the problem. (Although you can bet I will take it apart, clean and lube it!)

Oh and BTW, yes, I believe the ABS recall was done. The car had one owner and every factory service before I bought it. Why would that effect anything?

Anyone?

[Disco Mike]

I am drawing a blank, hope you find it and let us know what you find.
Mike

[psg]

As a wild guess I'd say your cruise control is somehow enaging itself even though you have it off, perhaps something in the steering wheel where the accel button is. I'd pull whatever fuse powers the system or better yet unhook the cruise control cable from the throttle body and see if you stilll have the problem.

[Rovin4life]

had the same complaint a few days ago,

basically in the cold the carbon builds up and the frost from there takes effect.

take off the intake hose, get you a can of carb cleaner and spray it down and clean it up.

while you are there check to see if your throttle body gasket, the little gasket underneathe the throttle is also leaking.

if it is go to the dealer get a new kit and take off the throttle and clean it off and install the new gasket.

by the way the throttle body gasket loses coolant.

[troverman]

The temperature (according to climate control) was -3F. After that out of control trip, I took the hose off, and found the throttle valve and housing around the valve to be pretty clean--I easily wiped off light residue with paper towels, shiny throttle body & valve, both sides. Plus, even before I cleaned it, that butterfly valve snapped back every time. It seemed it was impossible that it was sticking anyway, because remember, the engine was INCREASING RPM's on its own. (Say going steady 55mph at 2100 RPM's, take foot off gas entirely (pedal returns to top of stroke), RPMS and speed continue to build (going up hills w/foot entirely off slowed car somewhat), but when it got so fast that it had to be put in neutral, RPM's immediately went to 5,000 RPM's and I shut it off. Today, (same trip) I have pulled the vacuum hose for cruise rubber bladder. Although the temp is warmer (+10F), the car had no problems at all...

[smileyq]

Did you ever figure out what was causing this problem? This sounds weird and I would like to know if you were able to figure it out.

[stb616]

Originally Posted by beezel

had the same complaint a few days ago,

basically in the cold the carbon builds up and the frost from there takes effect.

take off the intake hose, get you a can of carb cleaner and spray it down and clean it up.

while you are there check to see if your throttle body gasket, the little gasket underneathe the throttle is also leaking.

if it is go to the dealer get a new kit and take off the throttle and clean it off and install the new gasket.

by the way the throttle body gasket loses coolant.

Try a bottle of SEAFOAM. Very easy to do. Follow the instructions on the can. You suck it into the intake via the pcv or break booster vacume, let it sit for a few. Start it up and run at over 3kRPM or take for a drive and run it hard.

Don't worry the HUGE amount of smoke coming from the tail pipe means the SeaFoam is doing its job.

First time I used it on a car I thought I wrecked it.

[OkieRover]

Originally Posted by troverman

because you are flying 75mph in a 45 zone, and the pedal is not stuck, and the brakes aren't strong enough to slow down the truck? So you are forced to put it into neutral and pull off, and the engine immediately and continuously revs at 5,000 RPM or more, so you immediately shut it off!

And the judges say ....

[Juanflaco]

I'm new here and not sure how helpful this will be, but here goes. I'm researching '00 and '01 Disco II's and came across this recall that effects both years - doesn't sound exactly like your situation, but worth a look.

On a few rigs I've called the dealership - they look up the VIN and will let you know right there if any recalls have yet to be done on the vehicle.

2000 LAND ROVER DISCOVERY II VEHICLE SPEED CONTROL
Recall Date: 01/23/2002

Summary:
ON SOME SPORT UTILITY VEHICLES, THE ACCELERATOR CABLE COULD HAVE BECOME KINKED DURING VEHICLE ASSEMBLY, RESULTING IN CHAFFING OF THE CABLE. CONTINUED CHAFFING CAN LEAD TO BREAKAGE OF THE INTERIOR CABLE STRANDS.

Consequence:
BREAKAGE OF THE CABLE STRANDS CAN RESULT IN THE THROTTLE BEING STUCK IN THE OPEN POSITION, INCREASING THE RISK OF A CRASH.

Remedy:
DEALERS WILL INSPECT AND REPLACE THE DAMAGED CABLES WHERE NECESSARY. OWNER NOTIFICATION BEGAN MARCH 6, 2002. OWNERS WHO TAKE THEIR VEHICLES TO AN AUTHORIZED DEALER ON AN AGREED UPON SERVICE DATE AND DO NOT RECEIVE THE FREE REMEDY WITHIN A REASONABLE TIME SHOULD CONTACT LAND ROVER AT 1-301-731-9040.

Potential Units Affected: 64925

Might be worth a call.

[Gate7]

Not that I know much, but here's my 2 cents worth. You said it happenend in the morning, how long after you started the car did u start driving? Just curious in case the automatic choke was still going. I know the revs were high but isn't it possible the choke could have caused it?

[Disco Mike]

Originally Posted by Gate7

Not that I know much, but here's my 2 cents worth. You said it happenend in the morning, how long after you started the car did u start driving? Just curious in case the automatic choke was still going. I know the revs were high but isn't it possible the choke could have caused it?

Rovers with fuel injection don't have chokes.
The only thing I can think of to check is the stepper motor and even that is a stretch.
Mike

[troverman]

It has not done it since and weeks ago I plugged the cruise back in. I took the Idle Air Control Valve (IACV) off, and found it definitely was sticking, to the point where it stuck fully closed. I had to use plenty of WD40 and a small screwdriver to get it to open, then it stuck open. So, I think this was possibly it? It has not done it since, and has actually been completely reliable. Thanks for the replies....