Car Applies Throttle on its Own...
#1
Senior Member
Thread Starter
Join Date: Mar 2002
Location: Dallas, TX
Posts: 594
Likes: 0
Received 0 Likes
on
0 Posts
Car: '89 Chevrolet Camaro IROC-Z
Engine: L98
Transmission: TH-700R4
Axle/Gears: B&W 2.77 Posi
Car Applies Throttle on its Own...
Here's a new one:
So I'm driving my '89 IROC in the rain tonight, and I notice some "unexpected acceleration". Not only did the speed of the car increase as though I taking off from a light normally, but I noticed the gas pedal falling beneath my foot. I had to put on the breaks so I didn't hit the car in front of me. It was fine when I was at a light, but when I started coasting again after taking off, I noticed it happening again. Needless to say, this is kinda scary enough to begin with--let alone at night in the rain on a busy city street.
My only guess is faulty cruise control. However, the cruise control has never worked on this car since I've had it (4 years or so). It's never even "kind of" worked; it simply hasn't done anything. The system is still in tact and connected, as far as I know, but it wasn't on when this started happening.
Any ideas?
So I'm driving my '89 IROC in the rain tonight, and I notice some "unexpected acceleration". Not only did the speed of the car increase as though I taking off from a light normally, but I noticed the gas pedal falling beneath my foot. I had to put on the breaks so I didn't hit the car in front of me. It was fine when I was at a light, but when I started coasting again after taking off, I noticed it happening again. Needless to say, this is kinda scary enough to begin with--let alone at night in the rain on a busy city street.
My only guess is faulty cruise control. However, the cruise control has never worked on this car since I've had it (4 years or so). It's never even "kind of" worked; it simply hasn't done anything. The system is still in tact and connected, as far as I know, but it wasn't on when this started happening.
Any ideas?
#2
Senior Member
iTrader: (1)
Join Date: Aug 2006
Location: Knoxville, TN
Posts: 620
Likes: 0
Received 0 Likes
on
0 Posts
Car: '87 Camaro / '87 Chevy K10
Engine: 3.4L MPFI (soon) / 5.7L TBI
Transmission: 700R4 / 700R4
Axle/Gears: 3.42 / 3.73
Re: Car Applies Throttle on its Own...
I've always seen cruise control electrically controlling the engine, not physically pulling the throttle cable. I'd be checking the throttle cables for signs of damage.
#4
Member
Join Date: Jul 2007
Location: Michigan
Posts: 248
Likes: 0
Received 0 Likes
on
0 Posts
Car: 2007 Cobalt LT
Engine: M62'd 2.2L L61
Transmission: 4T45E 4-speed Automatic
Axle/Gears: Stock
Re: Car Applies Throttle on its Own...
My cruise control pulls the throttle cable - they were designed that way.
Mine works just fine, though sometimes it remembers my cruise - but higher, when I accidently flip the switch to the right (from off), and it takes off.
Mine works just fine, though sometimes it remembers my cruise - but higher, when I accidently flip the switch to the right (from off), and it takes off.
#6
Supreme Member
Join Date: Jul 2005
Location: North Central Mass.
Posts: 2,123
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1985 Berlinetta
Engine: Megasquirted TPI
Transmission: Transgo 700R4
Axle/Gears: 3.42
Re: Car Applies Throttle on its Own...
IF you are worried about it, disconnect and plug the vac line to the cruise control servo. The servo is vacuum operated. The amount of vac is controlled via the PWM of two valves.. If something is shorting I suppose it could engage.
#7
Senior Member
Join Date: Jul 2007
Location: Manchester, CT + Nashua, NH
Posts: 1,461
Likes: 0
Received 1 Like
on
1 Post
Car: 90 Firebird Formula
Engine: LO3
Transmission: T5
Axle/Gears: 3.08 one wheel peel
Re: Car Applies Throttle on its Own...
Or just pop the cruise control cable off the throttle body. It pops right off. Well, mine does but I have a TBI.
Also, yes, cruise control will usually cause the gaspedal to go down. However, my car has a sliding area on the throttle cable connector, so your gas pedal could stay up. But gravity pushes it down.
Also, yes, cruise control will usually cause the gaspedal to go down. However, my car has a sliding area on the throttle cable connector, so your gas pedal could stay up. But gravity pushes it down.
Trending Topics
#9
Supreme Member
Join Date: Jul 2005
Location: North Central Mass.
Posts: 2,123
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1985 Berlinetta
Engine: Megasquirted TPI
Transmission: Transgo 700R4
Axle/Gears: 3.42
Re: Car Applies Throttle on its Own...
Or just pop the cruise control cable off the throttle body. It pops right off. Well, mine does but I have a TBI.
Also, yes, cruise control will usually cause the gaspedal to go down. However, my car has a sliding area on the throttle cable connector, so your gas pedal could stay up. But gravity pushes it down.
Also, yes, cruise control will usually cause the gaspedal to go down. However, my car has a sliding area on the throttle cable connector, so your gas pedal could stay up. But gravity pushes it down.
#10
Senior Member
Thread Starter
Join Date: Mar 2002
Location: Dallas, TX
Posts: 594
Likes: 0
Received 0 Likes
on
0 Posts
Car: '89 Chevrolet Camaro IROC-Z
Engine: L98
Transmission: TH-700R4
Axle/Gears: B&W 2.77 Posi
Re: Car Applies Throttle on its Own...
Yeah, I'll prob. end up pulling the cable off of the TB.
Are there any tests I can run on the cruise control driving unit (i.e. the thing that actually pulls the throttle) to see where its getting its commands from? This is assuming that it is indeed what is causing the acceleration that coincides with the gas pedal going down without my command. I can't think of anything else that would cause that--the only other thing going to the TB is the TV cable from the tranny. But it pulls in the opposite direction, doesn't it?
I'm actually somewhat pleasantly surprised that the cruise control can do anything at all. I thought it was completely shot. Perhaps it can be revived to come on when I actually WANT it to?
Are there any tests I can run on the cruise control driving unit (i.e. the thing that actually pulls the throttle) to see where its getting its commands from? This is assuming that it is indeed what is causing the acceleration that coincides with the gas pedal going down without my command. I can't think of anything else that would cause that--the only other thing going to the TB is the TV cable from the tranny. But it pulls in the opposite direction, doesn't it?
I'm actually somewhat pleasantly surprised that the cruise control can do anything at all. I thought it was completely shot. Perhaps it can be revived to come on when I actually WANT it to?
#11
Supreme Member
Join Date: Jul 2005
Location: North Central Mass.
Posts: 2,123
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1985 Berlinetta
Engine: Megasquirted TPI
Transmission: Transgo 700R4
Axle/Gears: 3.42
Re: Car Applies Throttle on its Own...
There is a 4 (i think) connection plug on the servo. On terminal is common, the rest are to activate the valves. They you can take off the little cover over the valves, and actuate them with a 9 volt battery. If you have the engine running, it should even move the servo.
#13
Re: Car Applies Throttle on its Own...
I had the same thing in my old 82 grand prix 305 4 barrel a few years back , took it to the shop a few times, they never figured it out. I figured it was the cruise control because it always disengaged when I hit the breaks. I searched for a bad wire that was getting wet since it only happened in the rain but never found one so I just disconnected the cruise control. Mine would go almost full throttle when it would happen and never from a stop or under acceleration but only when I was not pushing the gas or the breaks like when slowing down for traffic or a red light. I disconnected the cruise control and never had it happen again.
Thread
Thread Starter
Forum
Replies
Last Post
Terrell351
Engine/Drivetrain/Suspension Parts for Sale
5
06-13-2021 01:13 PM
9192camaro
Engine/Drivetrain/Suspension Parts for Sale
16
02-03-2019 12:21 AM