Having trouble with my cruise control. Once engaged, the slightest change in speed causes the c.c. to speed the car up slightly to return to the set cruise speed, but it always overshoots so the c.c. let's off the throtle a bit, then undershoots the speed, so tries to speed up again.... it just keeps yo-yoing up and down a couple miles an hour; it never seems to be able to adjust the throtle properly to get itself at, and keep, the set speed. It's like a bad taxi driver (no offense to an taxi drivers out there, they're notorious for that here in Montreal.)

I don't know if it's the vacuum actuator or the or the c.c. transducer?

Help.

 

CC is vacuum controled on carb'ed cars but I don't know where the port is

 

Tried lubing all the throttle mechanism and speedo cables last night. Speedo needle isn't smooth, jumps a bit.

No change.

Can't locate any adjustment on the transducer.

 

Now that you said speedo jumps ,There is the problem you must have the old style unit ...Disconnect cabels from unit & lube them , Then on cable side there are 2 1/4 " screws remove them seperate housing , Mark your place. blow out dust from clutch side .Cable end ,spray with lube re assemble & test drive this has always worked good on the old style units . If yours is not this unit ,this Info is useless to you

 

it's a jummping speedo needle mean you need a new cable from speedo to tranny?

 

Do you have the old style? If so the cables are connected to it ,You never told us Make Model & Year,so I am guessing

 

It's a 1977 Delta 88 Royale

 

Hi Shane,
I had almost exactly the same problem with my 1983 Ninety Eight. From 77-83 I don't know how much change there was, but I'll bet it wasn't much because my system ran on vacuum too. Here's what I found: Check all your vacuum lines for signs of a leak. If you've got hardened old lines connecting the carb and transducer, they may look good but are not holding vacuum which can cause surging. Strangely enough, also make sure your carb is bolted down good and tight to the manifold so it doesn't have vacuum issues. The other thing to look for is a replacement transducer. (You're in Montreal? Check around salvage yards - also check Toronto greater Met area re-cyclers. Just based on age, it's possible the transducer is shot.

Allan R