2000 Expedition gas pedal stops working at light

[munky000527]

After waiting for a while at a light, my gas pedal stops working. The engine idles fine but no amount of pressure on the pedal with work to move the car. Once i restart the car it works fine. Anyone have any ideas about what the problem is?

 

[munky000527]

No one has any ideas?

 

[toms89]

Are you saying the vehicle does not move as you give it gas but the motor revs?? I will assume so because for the gas pedal to work one moment and not another makes no sense to me with the mechanical linkage a 2000 expy has.

My guess in that case would be the transmission shift module. In order for you to restart you would have to move shift lever to either neutral or park so you have changed shift module signals. Just my guess?! Try shifting the gears with out restart see if it makes difference.

 

[munky000527]

Are you saying the vehicle does not move as you give it gas but the motor revs??

No, the motor does not rev until I restart the vehicle. When a light turns green, sometimes I press down on the gas pedal and nothing happens. No reving, no movement, nothing. It's as if the pedal just does not work at all.

I have to restart my car in order to go. This has happened twice, with about two months in between.

 

[munky000527]

Can anyone help? I don't like being stuck at lights

 

[toms89]

Only thing I can think of is something is wrong with the adjustable pedals or something in the linkage is broken on either end. Weird that this happens only occasionally and while stopped.

What does motor sound like when this happens? Does the pedal feel change at all?

 

[toms89]

While motor is off take intake plumbing off ahead of throttle body and confirm throttle blade is opening with accelerator pedal movement. Maybe throttle shaft broke? Should be easy to confirm if the mechanicals are all working properly. If it appears to work ok... apply some resistance at the throttle plate as someone depresses the pedal and see if anything changes..

Just to confirm.... this is a 2000 expedition correct?? Because I believe later models went to throttle by wire and then your symptoms would make much more sense.

Im out of ideas otherwise..

 

[munky000527]

What does motor sound like when this happens? Does the pedal feel change at all?

Motor sound does not change at all and the pedal feel does not change either. No difference at all. The engine idles normally, but the car does not move at all and pressing down on the pedal does not do ANYTHING at all.

It is a 2000 Expedition for sure, I just double checked.

Thanks for all the help man I'll try out what you said and see what happens...

 

[munky000527]

It happened again, this time while I was moving.

I'm super confused, the accelerator cable is fine and everything at the throttle plate looks fine...

 

[ELVATO]

Did you have someone push on the gas pedal while you watched the cable and intake butterfly move? Did you do this with the engine on and off? Does everything seem to return to it's position smoothly?

It does seem more like a problem with electronic throttle control motors.

 

[Soldier777]

could be fuel pump?

 

[munky000527]

Did you have someone push on the gas pedal while you watched the cable and intake butterfly move? Did you do this with the engine on and off? Does everything seem to return to it's position smoothly?

Yes except I did it only with the engine off. I don't think I can look at the plate with the engine off cause there would be no filter for the air entering the engine. I have no reason to believe that there is anything affecting the movement of the cable because the car's acceleration isn't erratic at all.

could be fuel pump?

I don't think that could be it...the engine idles fine the pedal just stops working.

 

[Thermo]

THinking about everything that the Expy has, the only way for this to happen is for the adjustable pedal module to move as the pedal is stepped on. Even if you assume something like the Thottle position sensor was to have failed, the motor would still sense the increased air and give the corresponding amount of gas which would result in a rise in the RPMs.

The only other "possibility" and I am reaching here is that the truck had the motor replaced and when they did that, they upgraded the truck to a newer engine and they converted the truck over to the drive by wire setup. But, I am reaching here on that one.

 

[ELVATO]

Does it happen consistently? As in, you can idle for X amount of minutes and this will happen?

If possible, get it to where it won't rev, and pop the hood and manually turn the butterfly from the outside. This should take out any variable concerning the actual throttle.

Also, does it do this in both Drive and Neutral/Park when at the light?

 

[munky000527]

Does it happen consistently? As in, you can idle for X amount of minutes and this will happen?

If possible, get it to where it won't rev, and pop the hood and manually turn the butterfly from the outside. This should take out any variable concerning the actual throttle.

Also, does it do this in both Drive and Neutral/Park when at the light?

No it's just random, and it has only happened while driving, so it's not like I can just pop the hood in the middle of the street with everyone behind me waiting.

And yeah, once it happens, shifting gears does nothing to fix it. I have to turn off the engine and restart it.

 

[toms89]

Open hood. Pull intake hose off and take photos of throttle body both with the butterfly closed and open... get someone to press the accelerator pedal wide open. Make sure photo shows throttle plate and cable linkage. This should go a long way towards helping diagnose.

If this is a 2000 expy with mechanical linkage..there are only a few possibilites and they have been covered in this thread. This sure sounds like an electrical issue which would only with throttle by wire.