Another weird idle!

[KCz Eclipse]

Alright so I have read through some other threads and I can't find one that sounds like my problem. While my car is idling, it goes from about 1k to maybe 1400 rpms. While the rpms are bouncing, the boost gauge bounces as well. When its cold, it does this at about 2k, and when its warm, a little over 1k. I assume its a boost leak, but I'm not sure. I know it has a boost leak, due to the fact that 50% of the time I give it full thottle, the car about rattles my teeth out at full boost. This thread will probably get bumped, but let me know what you guys think.

Thanks in advance

Heres a couple videos.
[ame]http://www.youtube.com/watch?v=Bq7xy0aESEA[/ame]
[ame]http://www.youtube.com/watch?v=k1i2C279NDk[/ame]

Nobody?

 

[dsmer1]

why dont you fix your boost/vacuum leak first.

 

[tektic]

Fast idle air valve.
Get a new throttle body ov fiav block off plate.

 

[KCz Eclipse]

I would fix my boost leak, except it is something I can't really do myself. I have tried to make a tester but when I hooked it up and pressurized it, it never seemed to pressurize. For me to fix the leak, I would have to pay someone to do it. I have put $1200 into the car in the past 2 weeks, which bought me a new radiator, power steering pump, alternator, and labor. The car is a money pit, but it's fun. And what exactly does that valve do?

 

[Kod]

Dude if it wont pressurize thats because of the leak! Use the soapy water method, pressurize listen for where its leaking, and spray water with soap over the areas it can possibly leak from then watch for bubbles when you pressure it.

 

[KCz Eclipse]

But I have also heard that when doing a proper boost leak test, you are supossed to do something with the cams. I was able to find some little leaks aroun the bov valve and stuff, but nothing too major. Again the test I did was half ass, so I wasn't able to find much.

 

[kddrosos]

You have idle surge. Basically your engine is receiving too much air that's most likely unregistered, compensates with fuel, RPMs hit a peak cut-off point for fuel, process starts all over. Fix all boost leaks before throwing parts at it. Honestly, when I boost leak test, I just unhook the pipe at the TB elbow and plug it with a $0.60 Lowes 2" PVC end piece. Then I hook up my rigged tester to the pipe right after my turbo. It's not a complete test by any means, considering how prone the TB is to leaking, but it's fool proof for the IC piping. The TB is definitely the next thing to check for leaks. I ended up ditching my FIAV and ISC.

 

[Abe'sGST]

If you're not sure on how to do a BLT, search it on google. Fix that and go from there. Simple.

 

[dsmer1]

okay. phew, here we go. aanother way to detect a boost leak is with smoke. if you grab a cigar or a hukkah and blow into a vacuumline you can detect your leak. as for idle surge, there are 5 components that may be the culprit. base idle set screw(BISS), fast idle air valve(FIAV), a vacuum/boost leak, idle air control(IAC), or a dirty throttle body. i dont have the time to go into complete depth, but nere you go.

Terry's Talon Troubleshooting Tips #3 - Fast Idle (aka. Idle Surge)

its a great read for a man in your situation

 

[kddrosos]

Don't forget the Coolant Temp Sensor! That has stumped many a DSMers in the past with idle surge. Like DSMer1 is saying, IAC/FIAV and BISS play a big role also. This guy posts several helpful vids: [ame=http://www.youtube.com/watch?v=fdjadhUP1u4]Boost Leak Testing 201: Using the tool. - YouTube[/ame]

 

[tektic]

Check this out.

http://www.dsmtuners.com/forums/newbie-forum/177292-fiav-blockoff.html

You don't need the plate. I filled the holes with JB weld, covered it with masking tape and turned it over to let it dry.When I ripped it off it was a perfect solid blockage. No more fast idle when cold. no ill side effects. If you can't do this your self you should probably sell this car. Not trying to be mean, but if your going to pay for retail parts and labor your going to go broke quick. I fixed this on my car for under $10. I bought a new gasket for my throttle body and some jb weld.
Good Luck

 

[KCz Eclipse]

Okay, I say that I can't do any of it on my own, but I only say that because I'm affraid I will mess something up. The car is my daily driver and I work while being a full time college student. With some instructions I'm sure I could do anything on the car, I just don't want to screw anything up.

 

[dsmer1]

kdrosos- ive never heard of such a thing. ive got to check that out. thanks for the thought.

tektic- i did the same way. if you dont have money and want to go fast...

and to OP- an idle surge is a very miniscule task to fix. you shoulnt mess anything up as long as you make shure your intake has no vaccum leaks. go to my orginal post and go through his dignosis. its fairly straigh foward and helps you understand what is going on so that you may dignose your problem. you can fix everything for vurtally free.(with the exception on buying a new IAC or ISC which is 40 bucks or if you go to a local pull-a-part) but that idle surge will just get more annoying, trust me. heres a link to bloacking you FIAV for free

http://www.dsmtuners.com/forums/articles-intake-exhaust/391977-free-fiav-block.html

also, the FIAV and the IAC airways are connected through the FIAV itself. so blocking all will elimate FIAV and IAC. but BYPASSING you IAC can still be used. give both my articles a good read. ive been through this situation before so feel free to ask any questions

 

[KCz Eclipse]

Does this just block the FIAV. If so, I will probably just buy this and just do it right.

JM Fab FIAV Bypass Plate (DSM) - Modern Automotive Performance

 

[dsmer1]

yes that is is a BYPASS plate, which allows the IAC to still be used. but, that might not fix your problem. did you perform a boost/vacuum leak test yet??

 

[KCz Eclipse]

No, not yet. I haven't had the time between work and school.

 

[Bojangles465]

Coolant temp sensor or the o2 sensor is my guess

 

[dsmer1]

Conduct a blt first and then get back to us

 

[KCz Eclipse]

I will.

 

[KCz Eclipse]

Okay, no I havn't done a BLT yet, but I did take my car to an exhaust shop today. I just went there to get a quote on my mani back exhaust ($650 ) and the guy commented on my weird idle. He thinks that the idle problem is from cuttng my air can and installing a k&n filter. He told me that the car is gettin abnormal a readings and causing the idle. To me this does not seem like a possibility, but what do you guys think?

 

[Twinturbo120]

Okay, no I havn't done a BLT yet, but I did take my car to an exhaust shop today. I just went there to get a quote on my mani back exhaust ($650 ) and the guy commented on my weird idle. He thinks that the idle problem is from cuttng my air can and installing a k&n filter. He told me that the car is gettin abnormal a readings and causing the idle. To me this does not seem like a possibility, but what do you guys think?

Dude obviously doesn't know a thing about dsm's

 

[KCz Eclipse]

Thats what I was thinking. I thought that cutting the can and putting in a K&N filter was a pretty common/cheap upgrade. If it caused idle problems people probably wouldn't do it as often.