01tibby0702

OK everybody I got my car 2 years ago. No major repairs and it have about 180,000 miles.
I put a filter on my intake and took the air box out. But lately when my car is warmed up
It idles anywhere from 900 to 1100 rpms on start up. Then right after it turns over the car has a rough
Idle and fluxuates from 1100(on start up) and then drops to 500 or 300 or even 800 rpms and just cuts off.

I just replaced the filter (due to it being dirty) and reset my ecu ran it for a while and still the rpms fluxuate.And I notice the some times very few, when I put it in park rpms got up to 1500. One time it went to 2k and Stay there for a few but it rarely does that. Do you guys think its my TPS please help me with this one .and by the way Tiburon's rule my car is still running strong.

Stocker

If you think it might be the TPS, did you test it already?

01tibby0702

No i really dont know how to do that. But i pulled the sensor to the tps out(when it was on) and of course it reved high(my cell came on). I went to my car and floor it and it dropped to 1k and then i quick reved it and it seem to be more smooth in the rpms(of course it reved high due to the sensor).but when i pluged it back in the rpms settled down the cell went off in about 3 mins.
I cut the car off and on in it cranked up great. i even cut it off and on 7 times and it started up nice(no rough idling). i took the car to my uncles house and hook the dianostic up and it throw the tps code.he cleared them out and the car was running rough again.

Regit

have you ever changed the plugs or wires?if not ,180 on the speedo is quite a bit.

01tibby0702

i did change the wires allmost a year ago.spark plugs no and ive had the car for 2 years now still running great except the fluxuating rpms.i do feel the need to change the plugs.you guys have to see it on a bad day.
its pretty rough.when it boggles and i have the hood up i can hear the air sucking in when the rpms drop and when the rpms go up i cant hear any air flow and it keeps on doing that till the rpms levels out to 900 800k or if i floor it.

01tibby0702

oooo and my uncle says the the fillter i have on there now is sucking up the hot air in my engine.
and he says that thats why my ilding is bad and cutting off.im going to put the air box back on and see if it stops the rpm fluxuating if not then its something else.please everybody feel free to list all the things that
it could.

HyundaiKitCoupe

i would replace TPS first. it's easy, just takes 5 mins.

only use NGK iridium properly gapped to the smallest setting (#'s can be found on a sticker on the hood).

change fuel filter because they're supposed to be changed every 60,000 miles. though, the old Hyundai filters have a bypass so when they get clogged up there is still flow. fuel filter is located above the transmission next to the strut tower. you can find the DIY from here or google. it seems impossible at first but once you work your hands in there you can do it.

it might also be a coilpack. i would replace that anyways.

fuel pump could be bad, but that's likely not the case. it's very rare.

DTN

You will have at least two codes to be read on this problem. You need to take the vehicle to a local auto parts store, like advanced auto, or autozone, or canadian tire and they will read codes for free. Any one of those stores can read your code. The engine will fire codes when running that eratically. You will probly see a engine idle too high or too low.

Along with that code you will most likely see a MAF, TPS, Coolant temperature sensor, or random misfire code. If there are no other codes to be read, then the problem is likely the TPS or the spark plugs/wires.

The TPS can be tested with a multimeter. Just hook it up for ohms and test from the center pin to the edges while rotating the throttle body when the vehicle is off and the sensor is disconnected. You should see a smooth movement from start to finish of the throttle body rotation. If there is a dead spot or a jump then your problem is in the TPS. However, the vehicle will still not cause the problems you are experiencing with just the TPS being bad.

My guess is the MAF sensor. Since you just replaced the filter and said it was very dirty, the first thing I'd do is to clean off the MAF sensor using some MAF sensor or Electronics cleaner from the auto parts store. I keep some on hand because when I spray nitrous at a 75 shot, it will dirty up the MAF sensor with fuel and cause a shakey idle on the vehicle. When the MAF sensor is disconnected or installed backwards it will have the same problems you are experiencing. Remember that the arrow on the MAF sensor points in the direction of the air flow.

Check the gap on your plugs and ohm out your plug wires. The plug gap is written on the datasheet under the hood on the radiator support (the place where you set tools). The plug wires should have no more then 10,000 ohms per foot of plug wire.

DTN

HKC, you should never just throw parts at a car when you can easily test the part first. A $10 multimeter costs less then a TPS sensor and will determine weather or not you need a new one.

HyundaiKitCoupe

very true and also efficient.

i thought the mechanism inside of the TPS wears down after a while?

but i think at 180,000, it's good to know you have a new TPS anyways, along with some other cheap parts that will be reassuring to know are installed.