Car automatically accelerates

[whitesmoke]

My car has been acting weird lately. It starts up good and idels around 1k rpms but after ive been driving or letting it sit and idel, the rpms raise to 2,500-3,500 rpms. Sometimes when I'm driving and at a stoplight the idel will go up and when I put it in gear it will accelerate on it's own. Alsi when this starts to occur is wen im driving and i press my clutch in the rpms shoot up to 3,500 rpms and stay there. Any ideas on what would cause this will help.

I have 95 talon with a 6 bolt swap.

 

[Absit]

My throttle cable becomes super tight when this happens and then it loosens up

Loosen it. The sleeve expands when it gets hot so the cable gets tighter than it should. Loosen as far as you can with the pedal being all the way down still opening the throttle all the way.

 

[whitesmoke]

I have a spare isc laying around so I will just swap it for the hell of it. And I will loosen the throttle cable and see If that helps

 

[PanZero]

I doubt the ISC would do that. As the ISC functions with the ECU. That is why you must unplug things from the ECU to adjust the BISS.

Your ISC basically actuates when it reads a certain RPM from the ECU.

That is why the ISC motor is more likely to not work at idle and under deceleration only.

I'm not totally convinced your issue would be electrical. To me it seems more of a clutch engagement problem. Are you having any problems shifting?

It may also be a ECU problem, but I'm not sure because from what I've read on all the information I've read when fixing my idle did not make the car accelerate on its own in gear. Unless you mean with the clutch pushed in.

The only thing I kind of skimmed over because it wasn't highly relevant to the issue I had, was the CAS but from what I did read I'm not totally sure that could be the issue.

So check your ECU and let us know if you have any issues with certain gears like 5th/reverse or 1st gear.

Well, from what I know the ISC motor adjusts the throttle position even at idle, based on different engine loads (like if you have the air conditioner on/off) and atmospheric air pressure and temperature differences to keep the car idling at the same speed (around 800rpm in our cars). Not only that, it's something that usually fails in our cars, or at least the ones that came to Brazil (ISC motors and alternators are common problems around here, ), and from what I heard (thanksfully my car never had that problem) it causes some weirdness when the car is idling.

But if he tested it and it's not...

 

[Alan11]

Vacuum leak, Tps, and even you o2 sensor can make your car idle higher that normal....
any CEL..!?!?

 

[Absit]

Your ISC basically actuates when it reads a certain RPM from the ECU.

No, it starts working when the idle switch is engaged AND the ECU thinks you're trying to idle.

Well, from what I know the ISC motor adjusts the throttle position even at idle

It doesn't adjust throttle position, it allows more air to bypass the throttle plate based on necessity (accessories spinning, etc) to keep the engine going at the ECU's Target Idle.

Testing the ISC Coil resistance is only one part of testing the ISC, the next step is applying power to the ISC and ensuring it moves freely. I'm still confident the throttle cable being out of adjustment is the issue.

 

[whitesmoke]

No check eninge light. When my car starts doing that I pull over, pop the hood and the throttle
Cable is so tight it seems like it's going to snap

 

[Gysgt Guy]

No check eninge light. When my car starts doing that I pull over, pop the hood and the throttle
Cable is so tight it seems like it's going to snap

Did you loosen it?

 

[whitesmoke]

It's loose right now yes. But when the high rpms
Occur, the cable gets that tight. Then I loosen it

 

[targett27]

Do you have cruise control? my car had similar issues with a high idle and it turned out the cable that goes to the little black box on the firewall just left of the throttle body was kinked a little. I could also feel the resistance in the gas pedal if that helps.

 

[whitesmoke]

I have cruise control but it doesn't work. Everything on it looks good

 

[Inillortep]

As stupid as this may sound, I had the same problem because of a blown "Room" fuse. It was the fuse for all the interior lights and the radio. It blew and was acting like that my whole way home. I replaced it and it went back to running normal right away.

 

[whitesmoke]

I will check that. I put a new isc in and that wasn't it

 

[And_44]

Whitesmoke: I had exact problem in my 1990. I know the CC is mounted differently. But mine turned out that a nut came off the cable going from box to throtle in the CC box and was making the throttle cable stick when ever I pressed the throttle. I put the nut back on readjusted my throttle cables and problem never happened again.
Its diffently a throttle cable problem. If you will never use CC I'd suggest picking up a throttle cable from a car not equiped with it and bypass it entirely.