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Old 03-30-2005, 08:46 AM
yipcanjo yipcanjo is offline
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Join Date: Mar 20, 2005
Location: Seattle, WA
Posts: 651

Not sure how this happened, but I thought I'd mention it since someone here has probably been down the same road.

Anyhow, I was coming home from work yesterday and turned my cruise control on as a test. It's been acting up and will work some times and not others. It came on, test successful, so I turned it off again since traffic was slowing down. Unfortunately it seemed to NOT turn off completely as I could cruise along at about 35mph with my foot off of the gas pedal. I hit the brakes, tapped the gas, made sure the cruise unit was turned "off" but it was still revving high. Traffic was stopped in front of me so I had to apply the brakes as best I could and put it into neutral to fully stop. The engine revved VERY high and I had to turn the car off on the freeway. It dieseled a bit, finally shut off, and backfired. I started it up again, but it continued to rev high. Anyhooooo, I got 'er home with it still revving very high. It dieseled and backfired again, but shut off ok.

After opening the hood I noticed that the ball chain under the carb (going to the cruise control?) was completely stretched and tight. I pulled on it, loosened it, and the vehicle ran fine. I then noticed this morning that the throttle would rev high unless I pulled on that ball chain to slow it down. I sprayed some WD40 on there, worked it back and forth, and it seems to release properly now.

My questions: Does that chain go to the cruise control, throttle or both? Should I be nervous about using the cruise again? Should I look into that mechanism further?

Thoughts/advice/rants are welcome! [img]smile.gif[/img]



[ March 30, 2005, 02:48 PM: Message edited by: yipcanjo ]
: Jeepless...
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Old 03-30-2005, 09:16 AM
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Jayrodoh Jayrodoh is offline
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Join Date: Sep 07, 2004
Location: Cleveland
Posts: 3,221

That goes to the cruise control. I would unhook it until you know for sure that it works right. A buddy of mine had an old ford truck that suddenly floored itself in the driveway because of a faulty cruise, which took out the garage door and pushed the car inside the garage through the back wall of the garage. Needless to say his parents weren't very happy!
Honey?? What happened to the savings account? You bought a Jeep what??

86 Grand Wag Stock with Bulltear HEI
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Old 03-30-2005, 12:27 PM
yipcanjo yipcanjo is offline
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Join Date: Mar 20, 2005
Location: Seattle, WA
Posts: 651

Perhaps I ought to. It seems to be working fine now, but it makes me nervous....
: Jeepless...
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Old 03-30-2005, 11:54 PM
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brad_fsj10 brad_fsj10 is offline
350 Buick
Join Date: Nov 11, 2002
Location: Pell City, AL 35128
Posts: 908

The brake pedal curcuit should signal the vacuum to dump from the bellows vacuum circuit. Check the wire connection plug on the servo (on inner fender) to ensure it is not corroded and then that it is securely plugged in.

Look under the dash and majke sure the brake pedal is contacting the brake light switch when depressed. There is a solenoid near the brake pedal on the firewall (has a couple wires, one is purple) that looks like a blinker solenoid. Make sure the connector is securely plugged in on this. You can check this by turning your key on, switching the cruise on at the turn signal stem, and pushing the brake pedal. You should hear the solenoid click. You may have a bad solenoid, but I've not known these to go bad too often.

Pull the vacuum line to the bellows at the servo and apply vacuum to it; release. Make sure the bellows compresses and expands accordingly. If it lets loose when vacuum is removed, every time, i'd say your servo was acting up.

The chain is simply the mechanical linkage from the bellows to the throttle. It should be adjusted to provide just enough slack to allow the throttle plate to fully close, plus the exacting measurement of "and a little bit more".

[ March 31, 2005, 05:57 AM: Message edited by: brad_fsj10 ]
Brad Smith
79 J20
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Old 03-31-2005, 02:20 AM
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J4GRAND J4GRAND is offline
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Join Date: Apr 09, 2000
Location: Valparaiso, IN, USA
Posts: 5,931

To check the accelerator cable, remove the cable from the ball stud on the carb and see if it moves freely in the cable housing. Watch the clip that holds the cable to the stud, they like to fly off to who-knows-where when removing. I had a similar experience with a cable sticking on the highway one time. Very scary!

[ March 31, 2005, 08:21 AM: Message edited by: J4GRAND ]
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73 J4000 "The $LUT" 360 V8 bored .040 over Edelbrock 2131 1407 4V carb K8600 cam Dual Flowmaster 40 mufflers TH400 QT 3.73 Dana 44s
78 Cherokee Chief WT "Old Blue" 360 V8 4V TH400 QT
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