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Cruise control works, but surges... by AL87
Started on: 07-27-2013 04:25 PM
Replies: 5 (113 views)
Last post by: AL87 on 07-29-2013 09:23 PM
AL87
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Report this Post07-27-2013 04:25 PM Click Here to See the Profile for AL87Click Here to Email AL87Send a Private Message to AL87Edit/Delete MessageReply w/QuoteDirect Link to This Post
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.
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AL87
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Report this Post07-29-2013 08:28 PM Click Here to See the Profile for AL87Click Here to Email AL87Send a Private Message to AL87Edit/Delete MessageReply w/QuoteDirect Link to This Post
no one has any thoughts on this?
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TWright
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Report this Post07-29-2013 08:49 PM Click Here to See the Profile for TWrightClick Here to Email TWrightSend a Private Message to TWrightEdit/Delete MessageReply w/QuoteDirect Link to This Post
I don't think this is an accurate way to test this. I don't think the cruise control is optimized for a no load condition like you are testing.

Put the thing on the ground and give it a try. I'll bet it's OK.
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85 SE VIN 9
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Report this Post07-29-2013 09:01 PM Click Here to See the Profile for 85 SE VIN 9Click Here to Email 85 SE VIN 9Send a Private Message to 85 SE VIN 9Edit/Delete MessageReply w/QuoteDirect Link to This Post
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.
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fierofool
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Report this Post07-29-2013 09:16 PM Click Here to See the Profile for fierofoolClick Here to visit fierofool's HomePageClick Here to Email fierofoolSend a Private Message to fierofoolEdit/Delete MessageReply w/QuoteDirect Link to This Post
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.
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AL87
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Report this Post07-29-2013 09:23 PM Click Here to See the Profile for AL87Click Here to Email AL87Send a Private Message to AL87Edit/Delete MessageReply w/QuoteDirect Link to This Post
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...
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