wadd3456

My wifes car is wacky sometimes. Randomly (maybe 3x a month) she will pull up to a light, braking hard if it just changed, and the car will idle way down.... sometimes it will just turn off.

She can start it right back up again though. I has new plugs, new wires, a new fuel filter and a new coil pack just incase anyone was wondering. I would guess this problem is related to some sort of senor adjusting the idle.

Any ideas?

'treezy

TPS, Idle screw (tighten), throttle cable adjustment point.

Check all those. What gets me is why it only does it when brakin hard..
Maybe just chance.

wadd3456

<span style="color:#990000">** MOD EDIT: no need to quote here.


^^^</span>

Yup sometimes when there is a rapid deceleration followed by acceleration. Or when your driving along then rapidly decelerate. It seems like its some kind of issue where the computer cant adjust to the rpm change.

Replace the TPS?

Do I just tighten the idle screw, or does it have a certain spot it needs to be at? Sorry for the stupid question. Also, where is the idle screw? Im assuming the throttle body.

What do you mena by cable adjustment point?

thanks!

'treezy

I'm unfamiliar with the stock throttle body idle adjustment screw. I have had an aftermarket TB forever. But what it does is control how much the throttle body butterfly valve close when you completely let go of the acc. pedal. It should be completely closed.

The throttle cable adjustment point is located by the Thottle Body behind the IM. There are two 12mm bolts (maybe 11mm) which control the tension of the throttle cable when you completely let go of the acc. pedal (also affects idle). The two screws should not be at a point where the throttle cable is held taught when there is no one pressing on the acc. pedal. It should have some slack, common sense will let you know what's too much slack.

If you replace the TPS, replace it with the brand name Keifco. You most likely have a Dae Sung currently (gray).

Have you ever removed the TPS from the throttle body? Or unplugged it an unusual number of times?

wadd3456

<span style="color:#CC0000">** MOD EDIT : quote removed

^^^</span>
Oddly enough, one of the screws holding the TPS worked itself LOOSE a couple years ago. Weird huh?

So back to the idle adj. screw... Should I just turn it till the idle gets where it shoudl be. Hmm, now that I think of it, I havent a clue what the idle SHOULD be on this car. Do you?

As far as the throttle cable is concerned, I will take a peek at that as well.

'treezy

wait until the car is WARM until you start to adjust the idle.

Normal idle is 800-1000rpm. 1000rpm+ idle on cold starts is normal.

zoned019

If it was the idle screw it would have trouble idling at all times, not just during a "jerk" (like hard braking?)

I would second the TPS suggestion though, a loose/bad TPS does wacky things..
There's actually a TSB on them if you have an older DAE SUNG one, you can probably go to the dealer and get a brand new KEFICO for free, which should fix the problem.

Otherwise, how many miles on the car? If under 100k and you're the original owner (or a family member of the original owner) you should just drop it off at the dealer and let them do it, if I had warranty left I would take any problem to them. They'll replace anything, majiktib got a BRAND NEW engine + transmission INSTALLED, for nothing. If under 60k and you're the 2nd owner you have the same warranty.

BTW, RD1 = 96~99 tiburons (the kind I have), and RD2 = 00-01 tiburons (the kind you have)

HyundaiKitCoupe

yep yep, check the throttle adjustment to see if it's below idle. i agree with the guys on this one. it happens to my car due to usage of power in the brakes and brake lights.

Double_A

This has been happening on my brothers Audi 100 and grandmothers Chevy Impala. Its so incredibly random that I dont understand why its happening. So you guys think a bad TPS?

majik

I used to own a 1991 Buick Park Avenue Ultra. Near the end of the alternator's battery life, when I would hit the brakes while going downhill (not sure why downhill, maybe coincidence) the radio would shut off, engine would shut off, and it'd just coast. I could start it right back up, but somehow the braking caused all the electronics to cut off (including engine). Worth a shot maybe.

I'd check the battery connection. Maybe downhill while braking is moving the battery around (check if it's loose) and the connection is bad. shrug.gif