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How to replace throttle cable?

17K views 17 replies 10 participants last post by  worldtriad 
#1 ·
So,

Our Astro (2000 LS, AWD) did it's best Prius impersonation last weekend - the throttle cable snapped while my wife was driving the van and the throttle stuck wide open. After a fair bit of drama, she managed to safely stop the vehicle. The police and fire responded to her 911 call as the front brakes caught fire after she stopped. It took her a few minutes to realize to put the trans in neutral.

The throttle is still stuck open.

I opened the hood and noticed the throttle cable had a big kink in it, which undoubtedly led to wear on the cable, eventual fraying and breakage. I'm assuming the frayed end is stuck in the kink, holding the throttle open.

Anyway, can someone tell me how to remove and replace the cable?

Lessons learned so far:

1) Make sure that cable is properly routed after any work under the hood. Who knows who bent the cable and how long it had been bent.
2) Tell all the drivers in your household to put trans in neutral in any runaway situation.

Thanks
 
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#2 ·
Good to hear no one got hurt. Thats a pretty scary situation.

Assuming it like the old throttle cables. Unhook it from the gas pedal & squeeze the clips together holding it through the firewall and push the cable through to the engine compartment. Then unclip it from the throttle body. It much easier then you may think. Last one I had to do though was on a '85 Regal, so maybe things have changed a little? :shrug:
 
#3 ·
Its pretty self-explanatory. Each end of the cable will have a clip that holds the cable onto the throttle body linkage and gas pedal. Just as the cable sheath will have press clips that hold onto the firewall and throttle body bracket.

Glad everyone is ok.
 
#4 ·
That exact thing happened to me 4 days ago! I let off the gas and the van wouldn't slow down. I stomped on it, and it just made it go faster. I pulled to the side of the road and when the rear tire hit the loose dirt/gravel, it started to power brake, spinning that tire. I shut the engine off before I put the trans into park. I got a new cable and all is good. The hardest part is getting the throttle cable off the bracket on the engine itself, cuz it's hard to get your fingers in there. Everything else is easy. Good luck!
 
#6 ·
Astroplane said:
jim2000ls and OKCAstro, Please post pics of the damaged cable at your earliest convenience. This would give other members a heads up to see what to check on their vans. Thank You.
X2.........you guys got me worried now. :think:
 
#7 ·
Sorry, I didn't even think to take pictures of it when I changed it out. I can describe what happened though. Right where the throttle cable comes out of the firewall, the plastic sheath that surrounds the cable broke. That caused the metal that is spiraled around the cable to be able to bend, and through normal use, with the cable moving back and forth around where the plastic was broken, and where the spiraled metal was now able to bend, it caused the cable itself to fray. It was only a couple strands, but it caused the cable to bind up inside the spiraled metal. As the gas pedal was pressed down, those few loose strands from the cable balling up were enough that the throttle return spring on the throttle body was not enough to overcome the binding, thus keeping the throttle open. I was just cruising along at 65 MPH on the freeway. I let off the gas to slow down a bit for traffic, but it kept going at the same speed. I stomped on the gas pedal to see what's up, but that just made it go faster. The funny thing is that I liteally thought about the new Toyota's and the problem they have with speeding up on their own. I obviously know that problem couldn't relate to the Astro, but it's funny that I though about it. Anyway, as the van was speeding up, I pressed on the brake, which slowed me down, but when I let off the brake, it sped right back up. I pulled to the side of the freeway, but the engine was still trying to go as I was pressing the brake. I got slow enough to stop, but with the throttle stuck, the rear wheel was powerbraking (for lack of a better term) in the loose dirt and spinning, essentially doing a burnout. I shut the engine off before I put the tranny in park so that I didn't damage the tranny. I opened the hood, played with the throttle right at the throttle body, played with the gas pedal, and finally traced the throttle cable from the throttle body to the firewall and found the break in the plastic right at the firewall. I set the throttle to the closed position, started the van, and very lightly pressed the gas pedal until I got to speed and limped it to work. I only hit 3 stoplights on the way, so as I got close, I turned the key off and stopped at each red light. When the light turned green, I had to start the engine, shift to drive before the engine sped up too much, and the van lurched into motion. During lunch I borrowed a coworkers vehicle and got a throttle cable from a salvage yard that a friend owns. I swapped out the cable after work and went home. Getting the cable off the pedal is easy. Just pull it out of the slot. The plastic collar that holds the cable into the firewall isn't too bad. I just pulled the cable, from the engine side of the firewall, up, out, and then down to clear the two plastic tabs. The other side of the cable is a pain in the butt. There isn't much room in there to get the two tabs pressed in to get the cable out of the throttle body bracket. With a couple bad words and a 90 degree pick, I got it out. I pulled the kickdown cable from the tranny off the throttle linkage and pulled the cable off the round eccentric (spelling?). DO NOT PUT THE NEW CABLE ONTO THE BRACKET UNTIL YOU PUT THE ACTUAL CABLE BACK AROUND THE ECCENTRIC!!!!! Haha! I speak out of experience. It's tough to get in there anyway, and having the extra slack to wind the cable around is a big help. After I got the cable onto the eccentric, I snapped the cable into the bracket, again, and then threaded it through the firewall. After the plastic collar is snapped into the firewall, I went under the dash and put the cable back into the slot in the gas pedal. All is good now. I thought it was a huge coincidence that someone else had the same problem within just a couple days of me. Wierd. Anyway, long story, but now you know.
 
#9 ·
OKCAstro, Thank You for taking the time to post this info. Quick thinking on the road! The other cable is for the cruise control. Was there any recent work done on the van where the cable would be bent up and out of the way for better access? Fan shroud removed for any work? I'd like to know if jim2000ls' cable experienced failure in the same area. I'll check mine tomorrow.
 
#11 ·
Mine broke in the same area. I've got about 110,000 miles on it. Recent work in the area was a thermostat replacement 3 months, so that possibly bent the cable and it finally wore through and broke.

I got my throttle back to idle position this weekend and started the van to check for any other damage. I've got no PS/PB, so I think my PS pump failed during the episode. My wife probably drove a mile or so with the throttle stuck - managed to get off a highway and pull into a parking lot. Between the brakes, downshifting the tranny, a curb, some mud and a shrub she eventually stopped. It's easy to say after the fact to put the trans in neutral, but as someone who works in aviation I can tell you the reason that pilots practice emergency procedures all the time is to commit them to muscle memory. A panic situation is no place to try to figure out to put the trans in neutral for yourself if you haven't already been told about it.

So, I've told all the young drivers in my house (3 teenage daughters - yikes!) about what to do in a runaway situation.

Anyway, I don't have the skill to do that PS pump myself, so I'm going to have a shop replace that and the throttle cable. I'm also having them do a complete brake fluid flush as the fluid is now black from the high temps reached in the brakes. In fact, the front disc brakes actually caught fire after this episode due to the excessive heat.

I registered my failure with the NHTSA through their website. I searched through the database and found a fair number of similar episodes in Astros and Safaris ranging anywhere from 60,000 miles and up.

I think there's a design defect that if the cable gets kinked it's likely to eventually fail and cause a WOT episode.

I also called GM, but in their infinite customer service acumen they decided to just tell me my van was out of warranty and I didn't qualify for any compensation. They totally missed the boat that I wanted to report a safety issue.

So, I'd check your vans to make sure the cable hasn't been disturbed as that will lead to the issue.
 
#12 ·
I swapped out the engine in my Astro a few months ago, but when I pulled the throttle cable out of the way, I only pulled the throttle body side of the cable up to the wiring harness right above it on the firewall and left it there. I don't think that small amount of movement caused the cable sheath to break, but who knows. Wierd situation all the way around. I'm really surprised to hear about the brakes catching fire. I wouldn't have imagined they would get that hot in the short amount of time to get the van stopped. I was doing about 65 when my throttle stuck, and I got it stopped just fine without any other problems, but that's just what happened to me. With other variables, who knows what could have happened. What do you mean that other cable is the cruise control? You mean to tell me that black box on the firewall isn't the transmission with the kickdown cable coming out of it? :D I have no idea why I said kickdown cable. Brain fart I guess. I knew what it was and I called it something else. HAHA! Well, crazy situation, and I'm surprised at all the other reports of this happening as well. I didn't really think much about it, just a fluke, but then I saw this post. Hmm. Does that mean we should all park our vans and never drive them again out of fear they will run away with us? :lol:
 
#13 ·
Thanks again to both of you. I checked mine yesterday. Unhooked it from the pedal and the throttle. That allowed me to 'feel' the true condition of the stranded cable. No frays visible on either end. I've done a lot of work on my van recently and I remembered I had pulled the cable up a few times for better access to the front of the engine.
OKCAstro said:
Does that mean we should all park our vans and never drive them again out of fear they will run away with us? :lol:
I thought about just removing the cable altogether. Sure, there would be some road rage and serious tailgating everyday from other drivers, but safety first right? I guess I could start driving on the sidewalk ALL the time :lol:
 
#14 ·
The fray in the cable wasn't visible on mine. Well, I guess if I had taken both sides off and pulled all the slack towards the pedal side, it would have been visible. Right where the whole cable comes out of the firewall is where the sheath broke on mine. Without the support of the sheath, the metal that is spiraled around the inner cable was allowed to sag, whick caused the inner cable to rub at the kink, eventually causing a couple of the strands to break, and that's what got everything messed up. Oh well, problem fixed. Shouldn't we all be driving wide open throttle anyways? That's a lot more fun! :layrubber:
 
#16 ·
The electronic quadrajets in the late 80's did that a lot, the 9C1 malibus, firebirds and some cadillacs. People got
hurt driving those cars and police departments parked them permanently over this. Stuck throttle stuff is no
laughing matter to the person in the driver's seat. I'm glad your wife is OK. Cars are replaceable.
 
#18 ·
Okay, my van has recently had a bunch of work done, and the last major thing was a radiator replacement where the folks that did it, apparently got my throttle cable between my fan and the fan belt. As soon as I got in, I felt a strange vibration in the gas pedal that was never there before. Of course the place had just closed and my friend says there's no way they could have done anything to that....so since it drove okay other than that, I drove on. I was 125 miles from home, gassed up and was just pulling out when it felt like something grabbed at the gas pedal when I pressed down and then I heard this awful flapping type sound. I pulled right off and shut the engine off right away.

I got towed around the block and the mechanic said my throttle cable was the problem. They re-routed it to the tune of $125 which the other mechanic's place in KS reimbursed me for. I went on my merry way home. During this time my cruise control hadn't been working so I gave up trying to use it.

My van was in to be checked out for an oil leak and to check out the SES light right after I got home. While driving it around locally after getting it back, on a whim I tried my cruise control and it worked.

So on a trip away this weekend, I engaged the cruise, and the discovered after braking that I was not slowing down but speeding up, and then realized that my throttle was stuck down quite a ways. I immediately started applying the brakes to slow myself down and then shifted into neutral right after that and then shut the engine off. Wasn't much fun finished my stop without power brakes but I did it.

I was in the middle of nowhere without any cell service or signal. So, I looked under the hood first and then reached up around the gas pedal inside and pulled and felt it let loose. I restarted the car and the engine was no longer revving up. At this point I hadn't made a connection to the cruise for sure so later on I engaged it again and sure enough, the pedal stuck again.

From that point on, I have not used the cruise. I am guessing I need to replace the throttle cable? What about the cruise, is that all related to the pedal sticking when it (down) shifts to maintain my speed up an incline? I just want all this niggly little crap to go away! I need my van more now that it's winter.
 
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