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Discussion Starter #1
I had a hour drive on the interstate in my 91 L to complete the other day. Thought I would use the cruise control as I don't use it much and it had always worked flawlessly before. All was fine until I pulled off the freeway and the engine wanted to keep the revs at the same level it has been running about 3K rpm (80 mph). I hit the brakes of course, turned the system off at the stalk, futzed with the switch at the brake pedal. Shut her down, it's better but now my idle is about 1.5 rpm, which seems higher than before.
Any thoughts on this problem?
 

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I had a hour drive on the interstate in my 91 L to complete the other day. Thought I would use the cruise control as I don't use it much and it had always worked flawlessly before. All was fine until I pulled off the freeway and the engine wanted to keep the revs at the same level it has been running about 3K rpm (80 mph). I hit the brakes of course, turned the system off at the stalk, futzed with the switch at the brake pedal. Shut her down, it's better but now my idle is about 1.5 rpm, which seems higher than before.
Any thoughts on this problem?
Vacuum line may have come undone. But not clear on what exactly happened.
When you got off the freeway when you hit the brakes the system turned off or not? As you mention you hit the button on the stalk too or just to make sure it was off?



jason
 

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You may have had a coincidental failure: I have seen my wife's '92S with high idle occasionally and traced it to the throttle cable boot (itty bitty thing that I'd love to have replacements for) at the throttle being broken into two pieces. Sometimes the upper piece slides up into the throttle rocker and keeps the throttle from fully closing. You can't tell much from throttle pedal feel. But you can check that with the car off, your throttle closed switch really clicks shut. Simply listen to the throttle area when someone pushes the throttle open the tiniest amount he can. You should hear a microswitch click open and then close when the throttle is released. Only a degree or so of rotation is all that should be required to open/close the clicker switch. The boot is under the hard plastic throttle mechanism guard under the separator and idle air controller hoses that connect to the AFM hose.

Michael
 

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You may have had a coincidental failure: I have seen my wife's '92S with high idle occasionally and traced it to the throttle cable boot (itty bitty thing that I'd love to have replacements for) at the throttle being broken into two pieces. Sometimes the upper piece slides up into the throttle rocker and keeps the throttle from fully closing. You can't tell much from throttle pedal feel. But you can check that with the car off, your throttle closed switch really clicks shut. Simply listen to the throttle area when someone pushes the throttle open the tiniest amount he can. You should hear a microswitch click open and then close when the throttle is released. Only a degree or so of rotation is all that should be required to open/close the clicker switch. The boot is under the hard plastic throttle mechanism guard under the separator and idle air controller hoses that connect to the AFM hose.

Michael
Your more than welcome to bring it by and I can take a look at it.
Located in Tempe/Scottsdale boarder.

Jason
 

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Discussion Starter #5
Thanks Jason, It's the Black Stallion from Scottsdale, now in Fresno. I'd love to bring it over, just a bit of a hike now. The problem seems to have gone away, this morning I started up and all seemed fine. Knock on Sangiovase...
 

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Thanks Jason, It's the Black Stallion from Scottsdale, now in Fresno. I'd love to bring it over, just a bit of a hike now. The problem seems to have gone away, this morning I started up and all seemed fine. Knock on Sangiovase...
Hey!!! Yeah that is a hike now. LOL!
Well if it acts up again we can try to help. Hope all is well in Fresno. Glad the Black Stallion is doing well.


Ciao!
Jason
 

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Well, I am not sure if my problem is related to this... but when you said that the rpms stuck at 3k or so, actually my L also does the same when I use cruise control in it. When I set the cruise control at certain speed, the speeds never keep stable but rpms will be fixed. For example when the cruise control is set and I am taking an exit, I use my brakes and slow down and the speed goes down but my rpms still stay at the same place where they are at the time of setting CC, then I have to switch of cruise control to release rpms. Its like the cruise control, controls rpms rather than speed. I thought of fixing it long time back, but I hardly use cruise control.

If anyone have any suggestions on fixing this, tht would be helpful.

-Pavan
 

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Touching the brake pedal should instantly DISABLE the cruise control, as a safety measure. The cars use separate switches (IIRC) for the CC disable and for the brake light actuation. What I read from this story is that Pavan's car has a problem with its CC brake sensor switch being non-functional. The brake light switch should be normally closed, and open when the pedal is in its resting position. This provides brake lights when the pedal is pressed OR when the switch base is bent sufficiently out of position, and is the reason some folks' brake lights stay on permanently and drain their batteries. I know this first hand.

I do not know the switch logic for the CC switch, but I'd have expected it to be normally open and closed only when the pedal presses against it. This would mean that the absence of the pedal would turn it off and that it would fail in such a way as to prevent the CC actuation. But that's just my opinion.

Best of luck in debugging this issue. I'd not be happy if the CC didn't disengage when the pedal is pressed.

Michael
 

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Touching the brake pedal should instantly DISABLE the cruise control, as a safety measure. The cars use separate switches (IIRC) for the CC disable and for the brake light actuation. What I read from this story is that Pavan's car has a problem with its CC brake sensor switch being non-functional. The brake light switch should be normally closed, and open when the pedal is in its resting position. This provides brake lights when the pedal is pressed OR when the switch base is bent sufficiently out of position, and is the reason some folks' brake lights stay on permanently and drain their batteries. I know this first hand.

I do not know the switch logic for the CC switch, but I'd have expected it to be normally open and closed only when the pedal presses against it. This would mean that the absence of the pedal would turn it off and that it would fail in such a way as to prevent the CC actuation. But that's just my opinion.

Best of luck in debugging this issue. I'd not be happy if the CC didn't disengage when the pedal is pressed.

Michael
Well to say more abt my CC 'features', whenever I set it at certain speed, the gas pedal would be stuck at tht position but the speed slowly goes down unless I keep my foot on the pedal slightly pressed to give it little throttle (like assisting it). But rpms seem to be fixed all the time when I set the cruise control. So, in a simple way, my CC control is not a complete CC, but it just releives me from pressing the gas pedal all the way from its rest position :). I think its my cruise control servo of whtever it is tht controls the throttle is not workin the way it should be.

-Pavan.
 
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