Cruise control doesn't work

[jonmon6691]

My cruise control hasn't worked since long before I bought it and I've had the car approx 4 mo. now. But I haven't cared until now. I am going on a 400+ mile trip and I can not afford another speeding ticket and I figure cruise control is my only hope, but unfortunately, it does not work.

I have no idea where to begin, besides fuses, I've checked all those.
It's a 93 mtx btw.
Any ideas, relays, hoses I should check? Is the mechanic my only option?

 

[projectSHO89]

In the "How do I..." section, there's a thread about the 89's CC system that also includes the 92.

The system on the 93 MTX should be nearly the same. Refer to it to get started.

Steve

 

[randy'sho]

check your cable going to the throttle body first and make sure it is in working condition!

 

[pitaSHO]

check your cable going to the throttle body first and make sure it is in working condition!

...Make sure it's connected. I bought a 95 MTX from the Bay area and drove it 700 miles to Vancouer, WA with no cruise. Turns out it was disconnected from the TB. 5 seconds later I had cruise.

If you end up needing a cruise module, I may have one. I also have the buttons from the steering wheel.

Best of luck.

Chris

 

[hawkeye18]

Are you serious? You are so incapable of managing your own speed that you have to have cruise control to keep it down? I mean, yeah, it sucks that your C/C doesn't work, mine didn't for a while too, but I still kept it to within 5mph over. You need to work on your speed setting skills.

 

[jonmon6691]

I don't know if this helps, but the engine is able to control its revs just fine while I do an EEC/IV test, does this mean that the TB control is working properly?

Are you serious? You are so incapable of managing your own speed that you have to have cruise control to keep it down? I mean, yeah, it sucks that your C/C doesn't work, mine didn't for a while too, but I still kept it to within 5mph over. You need to work on your speed setting skills.

Dude, I don't know if you're being sarcastic, but I was just kidding. Driving for 400+ miles without cruise control is annoying. And for the record, when all of the traffic around is doing close to 85-90, its hard to keep yourself from speeding. This is exaclty how I got my last speeding ticket on the same trip. But never the less, I still would like to have it fixed.

 

[projectSHO89]

I don't know if this helps, but the engine is able to control its revs just fine while I do an EEC/IV test, does this mean that the TB control is working properly?

Not applicable.

The speed control servo has a separate cable that that clips onto the throttle along side the throttle cable. Check that because it easily pops off.

Steve

 

[hawkeye18]

Dude, I don't know if you're being sarcastic, but I was just kidding. Driving for 400+ miles without cruise control is annoying. And for the record, when all of the traffic around is doing close to 85-90, its hard to keep yourself from speeding. This is exaclty how I got my last speeding ticket on the same trip. But never the less, I still would like to have it fixed.

Oh. Well in case you didn't know, it's kinda hard to pick up on humor in typing unless you give some overt clues, like an or a :laugh_ti: or a :angelnot: or something to that effect. They're there for a reason... to keep people like me from going "...are they freakin' serious...?"

 

[JRA2000TL]

...Make sure it's connected. I bought a 95 MTX from the Bay area and drove it 700 miles to Vancouer, WA with no cruise. Turns out it was disconnected from the TB. 5 seconds later I had cruise.
Chris

This exact thing happened to me on my 90. I bought it in Houston and had to drive it 500 miles home. I get out on the interstate and hit the cruise and it doesn't work. I figured, oh great...more stuff that doesn't work on this car. I get home and play around with it and the TB cable popped off. I connected it and it worked! I drove 500 miles home w/o cruise. Oh yeah, and the thing STILL keeps popping off; it won't stay on for long.

 

[TopGunnYFZ]

Yep mine does the same thing on my '90 I picked it up and the cruise worked, got in it the next day and it didnt work WTF....Popped the hood noticed the cable was off, put it back on and it worked but the damned thing will only stay on there till the first time i use cruise then it pops off again so i just said F it i dont need it.

 

[jonmon6691]

Here is a picture I just took of the TB, I'm guessing that the black box w/ the wires is the Cruise control module and it looks to be plugged in.

 

[jonmon6691]

Hey! I think i figured it out, but that leads to one more question...


I'm going to see if that fixed it right now...

As for that other question, the cruise control linkage has slots for adjusting the tension, how do I calibrate that, and what exactly does that affect?

 

[TopGunnYFZ]

Yep thats the problem, it will come off again though

 

[projectSHO89]

There is no adjustment required.

You've found the immediate cause of the failure. Put the cable back on and see if 1) the cruise now works and 2) if the cable stays on..

My 89's would pop off every few months....

Steve

 

[beaudeen]

Found that problem on mine ..pop the cable back on and put a zip tie around it..hasn't come off in 4 years..but now my cruise doesn't work..i'll dig into the electrical switches now..

 

[RonPorter]

Two things that I ran into over the years:

Does the horn work? if not, it's most likely the clockspring.

Another thing that happened to me on two different MTXs was that the vacuum line that comes in under the dash to the brake pedal (IIRC) had split on the end and obviously had a vacuum leak.

 

[beaudeen]

My horn works...I'll check that vacuum line today...the cruise just crapped out the other day...worked in the morning...dead in the afternoon...was wondering if the front engine mount play had something to do with wiring being stretched...i have a mount headed this way shortly..just started to get a small rub on the intake...

 

[hawkeye18]

Adjust the cruise control cable so that there is no slack when it's at idle. This will enable more precise control of speed.

 

[jonmon6691]

Thanks everyone, this could possibly be my most money saving fix yet .

Before adjusting it, it seemed to "pulse" the accelerator to try to maintain speed. But thanks to hawkeye18, I adjusted the slack and it's much smoother now.

 

[hawkeye18]

Glad I could help!