8

My daughter has a 2005 Jeep Liberty Sport. She drives it to school daily and then home after school with no problems. But, if she uses it to run around town on errands it starts but the gas pedal won't respond.

If she allows it to completely cool down then it will work. Today while waiting for the engine to cool she said she heard a "click" from under the hood and then she started it and the gas pedal worked...?

Does anyone have any ideas where to even start with this? Thanks and I appreciate it.

  • Let me see if I'm getting the right picture – on cold starts, there is no problem (home to school, long wait, school to home), but on a warm/hot start (running errands) the gas pedal is unresponsive until something has had time to cool down. Right so far? That leads to a couple of questions: 1) when running errands does the car start, but not respond to the accelerator? and 2) does the car ever stop responding to the pedal after a cold start – for example on a long drive when there would be time for it to get hot? – dlu Dec 24 '16 at 18:01
  • 1
    This could be the throttle cable sticking. Somehow affected by temperature. Try lubricated the cable. – Chenmunka Dec 24 '16 at 18:06
  • Thank you for your responses. In answer to your questions, 1)the car starts with no problems. 2) so far the car has not given any problems after a cold start. Even if driving 40 or more miles. It has only ever occurred when the drives are short distances or several short trips in a row. Also, she said she is getting a low engine oil light on, but oil level is fine. Should of included the oil light in original post but she just reminded me of it, as I was reading your comments to her. I inspected the throttle cable and it seems fine, moves freely even as vehicle does not respond to it moving. – Heath A Boddorf Dec 25 '16 at 3:14
  • 5
    Does the car have electronic throttle control or traditional throttle cable? I think 2005 is around the time when most car manufacturers were switching to electronic throttle control. – juhist Jan 30 '17 at 17:21
  • It could be a coolant temp-related issue. Coolant temperatures spike immediately after turning off a vehicle because there's no longer any cooling from the heat exchanger, but the engine is still hot and offloading heat into the coolant. It might be that the car believes it's overheating, which would explain why waiting a bit helps. I don't know how Jeep handles overtemperature conditions, but an unresponsive pedal is a possibility. – Hari Ganti Mar 14 '18 at 19:44
1

I'm 98% positive that the thottle in a Jeep Liberty is electronic, so probably the pedal isn't really connected to the throttle body. With this in mind, given your assestment on the behavior and the click your daughter heard, I would do the next:

  • Check the pedals, check that the connections are properlly set. Clean the metal contacts with a mild acid(vinegar might do, light coke is good too), then rinse with water and finally if you want to be extra that the contacts are really bonding use a 2000(or more) grit sandpaper a brush them lightly, so you can give it more surface to contact with, don't over do it.
  • Then follow the cables if you can. See that all wires are in good shape.
  • Now pop the hood and check the throttle body and the throttle actuator, maybe is getting stuck because of oldness. This is were I think you would find your gremlin.

An electronic Throttle works by sending a signal to the ECU, then It gets processed and if everything is OK, It should open the throttle body and give you full power. Some ecu's would let you turn on the engine but nerf the performance, other just sit there like a glorified paperweight.

This means that you could have one of two problems:

  • Disconnection by heat: This again can be separated in Two. Mechanically means that on plug, or cable, is disconnecting due to heat expansion. Could be a bad plug(corroded) or even a cut off cable that in some position makes a connection. The other is electronic, meaning that some component is getting so hot that the conductiveness of the material is getting diminished. Get a hold a off volt-amp-ohm tester and check connections. Also check for shorts, if you have "pimp her ride" check the accesories like a stereo.
  • You have some other flag in the ECU that makes it think that is not a good idea to move the car. This is way too broad, I know. But as you mentioned that the low oil light comming up when oil level is fine, then you have a sensor problem. Which usually works with a diaphragm, wich is Mechanical and in some situations sound like a "click" when it get bended. Even better try to replicate it.

All said, I'll be checking every connection from the pedal to Throttle body, and the sensors for Oil pressure and coolant. Cables are prone to breaking specially where it changes from flexible to rigid, like a plug or a bend. When packed, cables "get used to" the way they when connected. So it's easy to overlook that.

And my last tip, buy one off those OBDII dongles they come as cheap as 10 dolar to like a zillion, but any will do. OBDII it's a standard shared between cars/trucks/motorcycles manufacturers. You can get access to some data, statistics, error codes and some criptic messages in your cellphone with just an app. Which can lead to isolate the problem and troubleshoot electronics in aless-hard fashion, or not to get scamed by some questionable meachanic. Here they pullf off the old switch and bait, "Yup! We had to change your transmission, How'd like to pay?'" when they only changed a sensor.

0

Maybe the the cable from the throttle stucks. Try to find the cable which "controlls" the gas and check the dryness of it. Maybe the cable has no lubricity anymore. So if its too dry, put some oil on it and then try it again to put the foot hard on the throtle when its cool. Start the engine on neutral and keep holding the foot hard down. Until its hot and if you can idle the throttle ans step again on the gas then its fixed. If not try it again with more oil.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.