cavalier gas pedal sticks while in cng?! help!

[mshepshep]

i have a 2002 cavalier. the throttle likes to stick while on cng. this happens when you put the accelerator all the way to the floor. there is a point about 3/4 into the throttle that you feel a slight "ridge" or "resistance" to the pedal. After this point the throttle sticks. it will continue to go full bore until it shifts, then it comes unstuck. it happens mostly in first, 50% of the time in 2nd gear, and 25% time in 3rd and higher.
any ideas? please help?

[larrycng]

Re: cavalier gas pedal sticks while in cng?! help!

check you linkage real close for kinks. Have someone work the throttle while you watch the action under the Hood. Make sure throttle return spring is good. Also check motor mounts, if the engine torques over too much, that can cause sticking -- especially at full throttle.

Larrycng

[siai47]

Re: cavalier gas pedal sticks while in cng?! help!

A sticking throttle is very unusal and the car shouldn't be driven until you find out what's going on . There is no difference in the cables or linkage or the way the throttle operates between CNG and gasoline. Also, there are no linkages between the transmission and the throttle, it is all electronic on the 2002 Cavalier. You may be having the same issue on gasoline but because the engine produces less power on CNG, you may be opening the throttle further on CNG--to the point at which it sticks. First, if the engine is off and you are parked, does the throttle move smoothly from closed to wide open? If it doesn't, you need to look under the dash and make sure when you press the pedal down there are no wiring harnesses or anything else that the throttle cable can snag on. Next, look under the hood, follow the throttle cable down to the back of the engine and make sure there is nothing close to the pulley that the cable goes around and the shield is not rubbing on anything. Also, if you are lucky enough to have cruise control, make sure the cruise control cable (which connects to the same pulley) is not binding and holding the throttle open. As larrycng said, check the engine mount. The torque mount for the Cavalier is located under the car near the A/C compressor. It has a lot of movement but has a bolt in a slot that limits travel---unless it fell out. I suspect the upshift causes just enough movement in the engine to "unstick" the cable. As a last resort, you might want to change the cable itself--they are pretty cheap to buy and they can wear out or have a strand or two break which causes the cable not to move freely.

[Lancer Automotive Group]

Re: cavalier gas pedal sticks while in cng?! help!

Can you pull the CNG fuse under the hood to force the car to run on gasoline. Let me know if the problem still is still there after the fuse is pulled.

[mshepshep]

Re: cavalier gas pedal sticks while in cng?! help!

after further review the throttle does stick while running on gasoline as well. The pedal feels normal with no sticking at all while off. when running, it does stick. i opened the hood and a large radius cable comes off the CNG stuff that actually has been rubbing harshly on the hood (Paint is warn off, and cable is warn down maybe almost to cable). I could assume that it is sticking due to problems with this cable but i dont know what the cable goes to? I dont know if this is the throttle cable or not? anyone know. i can send pics if anyone wants to see a case of this. I looks like the cable is supposed to be in this location but it sure does rub alot on the hood.

[siai47]

Re: cavalier gas pedal sticks while in cng?! help!

The throttle cable attaches to the accelerator pedal inside the passenger compartment. The cable housing is anchored at the firewall. The other end of the housing is anchored at a bracket attached to the throttle body located on the rear of the engine. The other end of the cable is attached to a drum on the throttle body. The cable is inexpensive to buy and easy to change. The cable should also go through a small rectangular clip located on the GMS/MCV. If you want to keep the cable off the hood, you need to tiewrap it to the crossover pipe running from the low pressure regulator over to the GMS/MCV. When you are replacing the cable, rotate the drum on the throttle body fully by hand and make sure you don't feel any binding and that the return spring is working properly. If there is any binding, you need to remove the throttle body and inspect and clean it.

[Pato94]

Re: cavalier gas pedal sticks while in cng?! help!

My gas pedal in my 2000 cavalier also sticks while running on gas and cng. please let me know if you find a solution.

[kirkbenge]

Re: cavalier gas pedal sticks while in cng?! help!

My brother also had this problem in his 2001 cavalier. He recently paid to have a cruise control installed, and it seems to have fixed the issue. I don't know exactly what is involved in installing a cruise control. Other than the wiring, I think you may just attach a second cable (from the cruise control) to the throttle, and maybe, somehow the tension from that fixed the problem, I don't know.

It's also possible that the installer noticed a problem during the install and modified the throttle, replaced the cable, or did something else, but whatever they did seems to have worked.

So my advice is, if you were already thinking of installing a cruise control, do that first!

[rhiatt]

Re: cavalier gas pedal sticks while in cng?! help!

My 01 cavalier does the exact same thing, I usually kick it into neutral if i need to slow down. I havent investigated mine yet, it would be nice to floor it without it sticking because the cavalier is a GUTLESS WONDER! Anyways, looks like i'll have to take a closer look at my cables.

[kirkbenge]

Re: cavalier gas pedal sticks while in cng?! help!

The throttle on my 01 cavalier recently began sticking. At first it only happened very rarely, but recently it started sticking frequently. I looked up this old post remembering that I had posted here about my brothers experience. I decided to check my cable and throttle body. I found that when I rotated the drum on the throttle body by hand, that when I hit the maximum rotation, it stuck there. It just seemed to be "sticky". I took some WD-40 and lubed the drum and the cable to ensure that any friction points were fully lubed and rotated the drum over and over again by hand. The stickiness was almost immediately gone. It has now been almost two months since that simple fix, and I have not had a single problem since.

[Curtis]

Re: cavalier gas pedal sticks while in cng?! help!

Has anyone checked to see if GM has a service bulletin, or recall on this issue? This is a serious safety issue in a vehicle, as Toyota can attest to. I would recommend this to be a priority step. On the other hand, Toyota did come up with a fix for their problem... maybe it will fit on the Cavalier... Seriously, check for issues with the dealer and be sure it isn't hanging on a displaced floor mat.

[CNG Utah]

Re: cavalier gas pedal sticks while in cng?! help!

Kirkbenge, we've noticed sticky throttles on several Cavaliers that we've had. We'll have to try your fix on them in the future. On the last one it ended up being a broken motor mount. The engine would rotate a few degrees while under load and it was enough to make the cable catch on something.

I've also noticed that the 2002s just have a heavier throttle than the 2001 and earlier Cavaliers. Any Cavalier with factory cruise control also seems to have a heavier throttle.

-Derek