I need some help with a cruise control issue. I have a 90 LSC. When I set the cruise it would slow down then run like heck to get back up to speed. It would jerk me down the highway to the point I didn't want to run it anymore. THEN, it quit altogether. How do you diagnose and or fix the problem? I am an old school carburetor guy ,and quite honestly, not a Phord man. I don't know the first thing about the computer controlled stuff in this car. HELP!!!!! :Bang
Cruise control help
- Thread starter Ronbo
- Start date
OldSchool1
Dedicated LVC Member
Welcome.
Start by correcting any and all vacuum problems that you might have.
Start by correcting any and all vacuum problems that you might have.
Vacuum good to everything. No leaks anywhere. The car was meticulously taken care of when I bought it. 82000 orginal miles. Is there a way to check the BOO switch, or does it have anything to do with the cruise?OldSchool1 said:
:Beer
OldSchool1
Dedicated LVC Member
heheheRonbo said:
First, I had to look up just what the hell a BOO switch was
On our Marks, the electronic BOO switch above the brake pedal does not work with our cruise controls but the vacuum breaking switch in the same location does. No. I can't think of the correct name for it either
It's mechanical and works (I think) like a simple wedge. Step on the pedal and you break vacuum to the cruise control module in the fender. Hmm. Now ~there~ is something that I don't have a picture of.Funny thing is that I actually HEARD the line pop off the module on my 1989. It had about 85,000 miles on it at the time.
In the fender? Which one and where? Thanks for the help!! :BeerOldSchool1 said:hehehe
First, I had to look up just what the hell a BOO switch was
On our Marks, the electronic BOO switch above the brake pedal does not work with our cruise controls but the vacuum breaking switch in the same location does. No. I can't think of the correct name for it either
Funny thing is that I actually HEARD the line pop off the module on my 1989. It had about 85,000 miles on it at the time.
OldSchool1
Dedicated LVC Member
Ronbo said:
1989 Mark 7
LVC Member
Well I have a question now. Why does it take so long for the cruise control to kick in?
OldSchool1
Dedicated LVC Member
1) It works on vacuum1989 Mark 7 said:
2) There's about five things that have to happen to start the process
3) Safety
OldSchool1
Dedicated LVC Member
Trace the large soft vacuum lines into the driver's side fenderwell. You may be able to get to it by only removing the wheel well.Ronbo said:
1989 Mark 7
LVC Member
When I decelerate, it'll slow down, then run hard to get back up to speed. Am I having the same problems?
OldSchool1
Dedicated LVC Member
I dunno.1989 Mark 7 said:
Are you referring to your cruise control?
What conditions are present when this happens?
Uphill, down hill, no hill ?
1989 Mark 7
LVC Member
Cruise control. It was a slight downhill when I decel(ed) and then it ran like heck to get back up to speed.
OldSchool1
Dedicated LVC Member
That actually sounds like normal operation to me as our engines are just accellerating to maintain a set speed.1989 Mark 7 said: