Balky cruise control

[Rootus]

Anybody have experience with a balky cruise control -- specifically, what I'm seeing is that the CC won't keep the car at a steady speed. It gives a lot of throttle, overshoots the set speed by a couple mph, then closes the throttle and coasts until it undershoots the set speed, again by a couple mph. Rinse & repeat.

It was fine before, and then I had it unhooked for a while while I was using a Fox TB. I'm back to the stock setup now, and everything otherwise seems fine except for this.

 

[trav_19]

...no experience in my stangs cc no fun i never use it. seems weird that it happened after it was unplugged but my z71 does the flutter thing with hills and what not i though thats how they worked

 

[MLC Stang]

Here's my votes for the most likely culprits:

1. Vacuum leak somewhere in the system, or in the cruise control vacuum diaphram itself. (It's inside the driver side wheel well.)

2. Binding in the cruise control throttle cable or linkage.

I'd bet more on item #2 since you recently R&R'd it.

Good luck.

 

[GTA_V6_Mustang]

These is a service bulliten out for that, I will have to check wednesday to get the details on it but I know that was a problem with some of our stangs.

 

[Rootus]

Here's my votes for the most likely culprits:

1. Vacuum leak somewhere in the system, or in the cruise control vacuum diaphram itself. (It's inside the driver side wheel well.)

2. Binding in the cruise control throttle cable or linkage.

I'd bet more on item #2 since you recently R&R'd it.

Good luck.

I have an option #3 to add, now that I've had more time to think about this issue. I seem to remember there being a helper spring on the stock throttle body. Well, I don't have one installed any more (can't remember exactly why I ever removed it). Just the spring on the blade itself, which is enough for my foot but perhaps the CC malfunctions with the unexpectedly easy-to-open throttle.

Easily tested, and sometime this week I intend to rule that out as a cause.

Thanks for your help.

Dave

 

[GTA_V6_Mustang]

I have an option #3 to add, now that I've had more time to think about this issue. I seem to remember there being a helper spring on the stock throttle body. Well, I don't have one installed any more (can't remember exactly why I ever removed it). Just the spring on the blade itself, which is enough for my foot but perhaps the CC malfunctions with the unexpectedly easy-to-open throttle.

Easily tested, and sometime this week I intend to rule that out as a cause.

Thanks for your help.

Dave

You see you neglected to mention that..... lol Good luck

 

[Rootus]

You see you neglected to mention that..... lol Good luck

LMAO. Yeah, I had forgotten about it. After I created this thread I spent some time gazing at the whole contraption speculating on what could be fubar. That's when I remembered the spring .