Bad Idle (Video)

[deputy865]

Well my car has been idling terribly and im getting sick of it. Sometimes the idle will surge so low that the car will just stall and i dont really want to be stalling in the middle of the road!

Ill give some info on this...

The car will start and idle fine for a few minutes then it will start to slowly surge.. Then just do it more and more and more until after a long time of idling it will just stall out. Now when im driving.. If im driving at 2000rpms or more and i shift into neutral the RPMs will DROP DRAMATICALLY, sometimes stalling, if it doesnt stall it just sits there and surges so im forced to give the car a little gas to keep the idle up. You can see in the video where i rev the car up then let off..

This is just getting annoying and i want to know WHY its doing this. My car is also running rich. At the end of the video i show my guages and what they are showing when this happens.. I can take video or pictures of anything if needed.

Please help me out. Heres the video::
YouTube - Talon bad idle... why?


Thanks,

Shane

 

[Backinajiffy12]

recurculated BOV? Its really hard to pin-point what it is. my best advice would be to seach seach and more searching.

 

[pcnerd]

as was said above, are you venting your bov to the atmosphere.. that could cause a rich condition and idle issues.. also, you might want to check your IAC (Idle Air Control) valve located on your throttle body.. Try Unpluggin it and see if that changes anything in your idle surge.. I wouldn't run the car with it unplugged, unpluggin it is just for troubleshooting purposes.. Really it could be lots of things.. do you feel any loss of power or is it just at idle that your experiencing issues?

 

[Jeff99GS]

Could be a bad ISC (idle speed control) but usually that will throw a Check engine Light. Do you have a check engine light on?

 

[deputy865]

The Check Engine light is on. But the last time i had the CEL pulled it was due to the vacuum lines being plugged off. The CEL has been on forever for that same reason. I dont ven the BOV to the atmosphere either.

What do i do if i unplug the IAC? plug it right back in or am i looking for something??

Shane

 

[pcnerd]

The Check Engine light is on. But the last time i had the CEL pulled it was due to the vacuum lines being plugged off. The CEL has been on forever for that same reason. I dont ven the BOV to the atmosphere either.

What do i do if i unplug the IAC? plug it right back in or am i looking for something??

Shane

Just unplug it and see if your surging immediately stops.. if it does then you have a bad IAC.. they are known to go out quite often and I believe I have heard of it burning up the IAC drivers on your car's computer from constantly trying to adjust the IAC effectively casuing it to short..

 

[deputy865]

Do i just unplug it while the car is running.. Or unplug it, then start it? Are they expensive to replace?

Shane

 

[turbogst98]

Just unplug it and see if your surging immediately stops.. if it does then you have a bad IAC.. they are known to go out quite often and I believe I have heard of it burning up the IAC drivers on your car's computer from constantly trying to adjust the IAC effectively casuing it to short..

thats what it is most likely is
and yes they are expensive

 

[dsmchiz]

Its has not been suggested but check for boost leaks. I had a very similar problem when my intercooler cracked a weld. Could not for the life of me figure out what was causing the problem and I did stall all the time. So check for leaks.

Chad

 

[deputy865]

Its has not been suggested but check for boost leaks. I had a very similar problem when my intercooler cracked a weld. Could not for the life of me figure out what was causing the problem and I did stall all the time. So check for leaks.

Chad

Ill do that for sure. So far, for ALL the problems i have posted with my DSM, people have said to check for boost leaks.. I sort of ignored them thinking that it didnt make much sense to do, but im gonna do it now


Shane

 

[viprez586]

Just unplug it and see if your surging immediately stops.. if it does then you have a bad IAC.. they are known to go out quite often and I believe I have heard of it burning up the IAC drivers on your car's computer from constantly trying to adjust the IAC effectively casuing it to short..

If you unplug your IAC the car will die, trust me.

Go to the link below to actually test it the right way.
DSMISC FAQS page
If it is bad, this is the cheapest place to buy it from. I've looked around for prices and they're the best IMHO.

Boost leaks and where they occur:
First of all you need to
A. Car up to operating temp.
B. Remove your oil cap so your don't build excessive crankcase pressure
C. Rotate your engine to avoid valve overlap
D. Remove your intake pipe.
E. Only pressurise the system to the max boost level you intend to run (20+)
F. Remove the line that runs to your BCS and cap off the pressure source. This goes for a MBC as well.

Now your ready to grab a spray bottle with soapy water and begin the fun.
The places it can leak from:
Couplers + they're clamps. (these can crack too)
Injector lower seals
Compressor housing seal
J-pipe or compressor outlet
Intercooler
Vacuum lines
Defective PCV valve
Brake booster line
Intake manifold gasket
Throttle body gasket(on 1gs there is 2)
Throttle body shaft seals

I'm sure i forgot some places but that should get you started.
I noticed in the video you have a narrowband air/fuel gauge , neat little light show hey? Well sorry to say but it's totally inaccurate, if you want the best way to monitor those AFRs get a wideband.

 

[deputy865]

I was reading on how to test my IAC... But i dont think i have the stuff to do it. Is there any other way to do it?

Yes i know i need to get a wideband.. I do know im running rich though.. There is a handful of stuff i need to get for the car. Sorry for all the stupid questions.. I just want to do things right the first time. AND i have a hard time trying to understand what all the abbreviations mean. Im still a noob with DSMs..

Shane

 

[viprez586]

Well our FAQ is good, but there is a "big gulp" of information on the net.
Here is some sites to get you started and familiarized with terminology and basic maintenance, mods, etc.

A lot of mods + good info. VFAQ Site - Visual Frequently Answered Questions
Good site for terminology and common questions1000 Already Answered Questions - Index page
Good transmission FAQ TRE TECH TIPS
"RRE's Injector Chooser Assistant"Road Race Engineering's Eclipse Fuel Delivery Upgrades

I'd hunt some more but I'm tired, and this should get you started. Researching on stuff helps a ton!

You need an Ohm meter to test your IAC's coils.
If you don't have one...well they're cheap...you could probably walk into radioshack and ask them to borrow an ohm meter for a second if you really don't want to buy one.

 

[deputy865]

Could i get an auto place to do it possibly? I know Autozone goes out and pulls the CEL.. Ill have it re-pulled to see what it tells me.

Shane