Scary Situation

[DecOFlaherty]

In my 2002:

I pulled out of a street on to a much busier road, going ~40mph. When I let off the gas, the car didn't slow. The breaks didn't do anything (or at least not much) After swerving around a few cars and blowing a red light, something let up and the car began to slow.
It all happened pretty fast, so no, I didn't throw it in Neutral. Also, It wasn't the floor mats.

Luckily, no one was hurt and the only thing that appears to be damaged is my e-break. I had it towed to my local mechanic and he said he didn't find anything "definitive" There were some "pivots joints" that were a little rusty, so he lubed them. he said he checked all the linkages.

I messed around with it a little and tried to recreate the problem in neutral, but I couldn't.

Does anyone have any ideas? All I could think of is the throttle or the linkages. Someone in work mentioned cruise control. I suppose I could of accidentally put it in CC and something is wrong so the break couldn't shut it off.

Thanks in advance.

 

[Number Twelve]

These things get crud in the throttle plate area. Try cleaning in there.

 

[Number4]

Throttle is all mechanical, something would have had to catch.

 

[Number Twelve]

Throttle is all mechanical, something would have had to catch.

I'm not so familiar with these cars that I know which years are, "fly by wire". Sorry. My bad.

If it's all mechanical on this one, this problem requires immediate attention!
Get in there and stare at it until you find the sticking point. Your life depends on it!

 

[Turdle]

Take a look at the linkages for the accelerator and cruise control cables that attach to the throttle body. I had it happen once when I was racing a mustang in the Turdle Wagon. I don't know if it was quick thinking, or just plain luck , but I switched off the truck in attempt to save my life. Thankfully it worked. The feeling of total loss of control while accelerating as fast as the engine can pull-is very mind altering to say the least.
My issue was self induced due to the severe state of modifications performed, however I did learn something:


There is a spring inside a plastic tube, which can develop a "snag" causing the throttle to not return to the idle position. Both move when the accelerator pedal is pressed. Check it closely for anything cracked or broken. Check the plastic retainer for the cables in the throttle linkage bracket, make sure they are held tight and straight.

You may need to remove a cover to see the throttle body and linkage.

 

[swshawaii]

IIRC, 2004 and newer Explorer's use electronic throttle control (throttle-by-wire) for both engines.

Very common question is "Where's my IAC?" usually asked in the 2002-05 Gen 3 sub forum. LOL

 

[swshawaii]

Great advice from Turdle. As Number Twelve said, check the butterfly plate for carbon and varnish deposits causing the throttle to stick. While you're in there use a firm toothbrush and lot's of clean rags to clean. Throttle return spring is very strong, use a piece of PCV pipe or a wood to hold it open.

https://www.google.com/search?q=crc...d=0ahUKEwiCt4zgvKvQAhXpjFQKHYyoBUIQ_AUIuQEoAQ

 

[plasticseng]

What condition are your motor mounts in? I have seen a broken motor mount allow the engine to torque up and pull the cable tight, opening the throttle. The more the throttle opens, the more it torques the engine up. I'm not sure if is possible in this configuration or not, but may be worth a quick look.

 

[imp]

What condition are your motor mounts in? I have seen a broken motor mount allow the engine to torque up and pull the cable tight, opening the throttle. The more the throttle opens, the more it torques the engine up. I'm not sure if is possible in this configuration or not, but may be worth a quick look.

When I had my service station, a Chevy came in experiencing a "bouncing hood". The left-hand motor mount had broken clean away, so when the engine developed adequate torque to lift itself, it swung upwards and hit the hood! True story! imp

 

[imp]

In this case, @DecOFlaherty , I would remove the possibility of Speed Control involvement altogether by disconnecting it's fitting at the Throttle Body. Then go about checking for binding anywhere in the cable system, including the pivot under the dashboard.
imp

 

[Number Twelve]

"bouncing hood".

In the 1970's it was standard, "used car lot" procedure to open the hood, get in the car, lock the brakes, and rev the engine in first, then reverse, to check the motor mounts. Quick, easy, and definitive test that can be done by one person in 1 minute!

 

[imp]

In the 1970's it was standard, "used car lot" procedure to open the hood, get in the car, lock the brakes, and rev the engine in first, then reverse, to check the motor mounts. Quick, easy, and definitive test that can be done by one person in 1 minute!

@Number Twelve
I actually saw that 350 lift up and twist over a good six inches! Took pretty good throttle to do it. Off the gas, it bounced back down shaking the whole car. Quite an experience. imp

BTW, seems to me the manufacturers later started supplying mounts with straps or even chains, to prevent severe engine movement with broken rubber bond.

 

[Number Twelve]

with straps or even chains,

I remember seeing motor mounts with extra steel ears or plates which overlapped. If the rubber broke, the steel ears would limit the lifting movement to maybe 2 inches past what the rubber would allow before it broke.

 

[SyberTiger]

I remember as a teen we had a '69 Buick Wildcat with a 454 V-8. One day at a stop light (my brother driving) the engine all of a sudden torqued up like someone had mashed the accelerator. He slammed on the brakes and the wheels spun and spun (posi-traction). Damned if we were lucky we didn't leaped out into the intersection. After about 5 or 8 seconds the throttle went back down to idle. Very scary. Anyhow, we managed to get home without incident. After an investigation it turned out that both motor mounts on the front failed. In special circumstances this allowed the engine block to rise up in the front and when this happened it pulled the accelerator linkage and the more the linkage was pulled the more the engine would rev up causing the engine to rise more and pull the linkage even more. I don't know if this scenario is possible on the 2002 Explorer but I'd be interested in knowing what you find as I have a 2002 4x4 V-8.

 

[imp]

I remember as a teen we had a '69 Buick Wildcat with a 454 V-8. One day at a stop light (my brother driving) the engine all of a sudden torqued up like someone had mashed the accelerator. He slammed on the brakes and the wheels spun and spun (posi-traction). Damned if we were lucky we didn't leaped out into the intersection. After about 5 or 8 seconds the throttle went back down to idle. Very scary. Anyhow, we managed to get home without incident. After an investigation it turned out that both motor mounts on the front failed. In special circumstances this allowed the engine block to rise up in the front and when this happened it pulled the accelerator linkage and the more the linkage was pulled the more the engine would rev up causing the engine to rise more and pull the linkage even more. I don't know if this scenario is possible on the 2002 Explorer but I'd be interested in knowing what you find as I have a 2002 4x4 V-8.

@SyberTiger
IMO extremely remote possibility given today's designs. Especially with "Drive by Wire", the throttle position is unaffected by ANYTHING except gas pedal position. Also, those very excruciating moments when 4-wheeling years ago, when your vehicle bounced a bit too much while negotiating a very steep climb, especially partly sideways, when the carburetor belched, hiccupped, and the engine died, leaving you standing on the brake, scared as hell, and considering your options, such conditions are GONE. Today's EFI engines will even run UPSIDE DOWN, until the oil all runs out..... imp

 

[plasticseng]

IMP, the 2002's aren't drive by wire. They have a cable. I still haven't studied it to see if it is a possibility with that setup. There are probably safeguards like those mentioned above to keep it from happening.

 

[SyberTiger]

@SyberTiger
IMO extremely remote possibility given today's designs. Especially with "Drive by Wire", the throttle position is unaffected by ANYTHING except gas pedal position. Also, those very excruciating moments when 4-wheeling years ago, when your vehicle bounced a bit too much while negotiating a very steep climb, especially partly sideways, when the carburetor belched, hiccupped, and the engine died, leaving you standing on the brake, scared as hell, and considering your options, such conditions are GONE. Today's EFI engines will even run UPSIDE DOWN, until the oil all runs out..... imp

2002 does not have Drive-by-Wire. If I'm not mistaken, the switch over went into the 2003...2004 at the latest.

 

[imp]

IMP, the 2002's aren't drive by wire. They have a cable. I still haven't studied it to see if it is a possibility with that setup. There are probably safeguards like those mentioned above to keep it from happening.

@plasticseng
Yes, I'm aware of that. Throttle plate can bind with either system, though. Messing with my '04 with drive by wire, it threw 2 codes simultaneously, "TP stuck open" and "TP stuck closed", then came "Forced Engine Idle", it was evidently confused, as stuck open implies it could not idle, but that it did, smooth, like nothing had happened. Dead gas pedal, though.

Out on the road, forced engine idle would at least allow you to creep off the roadway. Forced Engine Shutdown I fear the most. The safeguards Ford designed-in for DBW are clever: a double-sided variable resistor with it's wiper arms hooked mechanically to the gas pedal. Moving it produces two equal voltages opposite in polarity. If it ever happens that PCM sees those voltages as not being equal, or moving in the same direction polarity-wise, it shuts down the engine. imp

 

[DecOFlaherty]

*** Solved ***

After checking a few things, I brought it to a another mechanic I know, who really gave it good look.

"Frayed Accelerator Cable"

 

[SyberTiger]

*** Solved ***

After checking a few things, I bought it to a another mechanic I know, who really gave it good look.

"Frayed Accelerator Cable"

Awesome...good job! Thanks for coming back to post the solution!