Okay, so testing the cruise control on a sbc 350 swap in an 88GT (with the rear wheels jacked up) it works after about 3-5 seconds holding the slide control on the signal stalk.
when it engages, it surges the rpm. idle is about 500-600. and it surges to 3k and then 4k and then 5k. at which point i disengage the cruise control.
lines seem to be fine, new hoses everywhere. obviously the vacum canister and servo are working, no rips in the rubber on the servo.
I dont know how to test the system past the electronics (which are working) I do suspect that the cable linkage has to be adjusted, or there is still a vacum problem somewhere... Let me know what you think.
How is it supposed to work? I tried the slide and the button. Nothing happened. However the other day the accelerator suddenly went down, i.e. was easier to press. Another time I seemed to notice a modest surge, but I wasn't pressing anything, at least not intentionally. My car is missing the clutch neutral safety switch, but I think the cruise control clutch switch is separate.
If you're going to check it on the road, hopefully it will be an open road.
The transmission should be in gear in order for the cruise to work correctly. If there is a vacuum leak, the engine will increase in rpm in its efforts to keep the vacuum constant. An area that's overlooked when searching for vacuum leaks is the bottom side of the vacuum canister. If you're using the Fiero canister, I'd remove it and check that. Also check the ends around the crimp seal.
when I pull hoses from the canister, it sucks air after sitting for a while...
I guessed it wouldn't work right when the rear got put up...
ALSO, in my personal daily driver fiero, I sometimes get that cruise control problem where it makes the throttle body go Wide-Open... very weird, and dangerous... I think theres something in the control stalk...