When i have the car in drive and i'm stopped at light etc..the steering wheel gives alot of feed back...they told me at the dealer that its because of the intake. they said that the engine idles alittle rough because of it. i don't belive them, so how can i adjust it...? and when i rev in nuetral...the rpms go up, but when they come down they go below idle and then kick back up...it almost sounds like it could stall when i do this but, its not that bad...kinda hard to explain...

thax

 

Two things. 1st, you may need to adjust your idle adjustment screw. Its on the throttle body and changes how "open" the plate is at idle. At the minimum, turn on the ac and defroster (to load the engine), and fiddle with the screw until you get a smooth idle. You can also completely clamp off the IAC feed tube (black tube that goes to a little motor-looking-thing on the back of the intake manifold). This will almost kill the engine. Adjust the screw until you get a barely smooth idle. Remove the blocking clamp. The revs will shoot up and then come back down to around 800-900 and your idle should be much better. This should all be done when the engine is warm.

The other possibility is that your TPS sensor is crapping out. It registers the throttle position and gives that to the engine. You can check the resistance with a Multimeter (they have specs on Webtech), or have your dealer look at it.

Try the idle adjustment first and see if that helps, though.

good luck,
ac

 

That is a side effect of a CAI.

The Idle is "rougher" with a CAI than with the stock airbox. The RPM rise/then drop is also a side effect of the CAI.

If you feel it is rather severe, you might want to try to adjust your idle up to 900 rpm vs the normal 800 rpm, and see if that makes any difference.

 

Good look, Curtas and Random!!

 

What adjusts the air flow at idle is the IAC(Idle Air Control), this is how the car adjust the idle to condictions. Its usually not best to adjust the factory set idle screw, its better just to adjust the TPS. When at idle the car actually doesn't draw the air through the throttle blade, but from the throttle bypass. In relative terms the bosch IAC that Hyundai uses is rather large for the application.

 

Random, would this also happen if I took the resonator off as well?
I find mine idleing kinda rough and low, even when the car is warmed up,...

Thanks

 

Try to reset the battery. It greatly reduced idles to my car after some mods that I did (header, exhaust, and cai).

 

I have the same problem with my idle droping and then kicking back up. . . but only in REALLY cold weather like below 32 degrees celcius. Sometimes i get a CEL but as soon as it warms up, it goes away. I took it to a Hyundai dealer and they said it's the timing due to the Air Temp sensor that i have dangling under really cold conditions. My CAI tube doesn't have a fitting for it so it kinda 'dangles'. No harm done, but i only feel the awkward idle when it's really cold and when the bay heats up, it naturally disappears. It runs pretty crappy in the morning but it's like that only in the winter. Maybe i should extend the Air temp. sensor to my interior and mount that sucker in there for the winter!
Hope this brings some light.

 

RICH-

FIX YOUR IAT SENSOR RIGHT AWAY!!!!!!

The MAF calculates air flow based on the IAT reading. If the IAT sensor is dangling in your engine compartment, it is reading HOT engine temp air, while your intake is sucking in COLD air.

This means that the MAF has to work VERY hard to keep the MAF element at a constant temp. So the MAF thinks that UNGODLY amount of air at engine compartment temps is flowing by rather than a normal amount of cold air is flowing by.

THAT is why you are getting the CEL errors. The engine is running HORRIBLY rich, and the O2 sensors tell the ECU that you are running rich, but the ECU overides the O2 sensor with the MAF reading.

If nothing else, just loosen up a hose clamp, and tuck the sensor and wire in there, and retighten the clamp.

Your car will run 100% better.

 

I have also had some problems with the idle dropping and being generally kinna rough. I have a cai but I noticed it after i took off a turbo flow, flow tech muffler i had on it. Im running without any muffler now, and I think that my car seems slower! Is that right? The exhaust system is factory, without the muffler. Shouldnt it be flowing easier and helping? Also can this be a contribuence to the ruff idle?