Idle Surge weird version

[tsi_turboawd]

When i start the car w/ engine cold 1st time of the day. My idle goes to 2k for about 10-20 secs. then my idle would just start to surge, bouncing up and down by -300 then back up(2k) over and over as it warms up. it gets really annoying and embarrasing to my neighbors

But when the engine temp is about warm and idle is normal it doesnt surge anymore, but my idle isnt rock steady all the time either.

CHECK THIS! 'sometimes' when i come up to a stop sign/light my car would just stall out

-intake hoses/connections OK
-ISC (reading ~38-39ohms on all) OK
-02 sensor should be OK
-ECU cap just replaced 8 months ago
-replaced 1G BOV crushed

wtf is going on

 

[91 NT Eclipse]

Check your TPS.

 

[tsi_turboawd]

thats the electrical thing on the side of the TB facing the front of the car right? ..how do i actually check the TPS?

..i might aswell replace it

 

[eXploitedGST]

is your bov vented or recirculated? this usually happens when its vented.. also check your BISS valve on your intake manifold.

 

[tsi_turboawd]

vented and BISS looks fine

 

[tsi_turboawd]

it didnt matter if its vented or recirculated, but now its recirculated.

I tested the TPS and its checks GOOD. Now should i go ahead and replace the Throttle Body? could be the FIAV.

 

[Blitzed95Eclips]

Clean the throttle body. You could have a boost leak anywhere causing this. Check all the intercooler pipes and whatnot.

 

[tsi_turboawd]

I already cleaned the TB a few months ago and didnt seem to help, 'maybe' worse since i may have gotten carb cleaner fluid in the TB hole slits. The I/C piping connections are tight btw.

remember:
*Idle surges when engine is 1st started until warm
*idle isnt steady sometimes
*car stall outs coming to a stop sometimes

 

[Blitzed95Eclips]

hmmm are you sure its surging and not cutting out on fuel. Im sure you know if its surge or not im just checking.

 

[tsi_turboawd]

Originally posted by Blitzed95Eclips
hmmm are you sure its surging and not cutting out on fuel. Im sure you know if its surge or not im just checking.

hmm.. i never really thought about 'cutting out on fuel.' Well when i floor it to redline the A/F gauge reads green rich and car doesnt miss.

If its a possibilty could it be my fuel pump?(i think not)

 

[mitsuspeed]

my car had the exact same problem until i did the EGR blockoff and got rid of some lines. i also had to pull and replace intercooler pipes at the same time so who knows, but my guess is you have a leak somewhere.......

 

[RuBiCaNT5X]

I had the same problem. My idle would jerk from 2k down to 1.5k and so forth. When I would get to an interesection and be stopped, the car felt like it was going to die. THe radio would cut in and out. What resolved it was unplugging my batter for 20 minutes and putting it back on. Don't ask me, I thought my idle speed control motor was shot.

 

[95IndyTSi]

I've got this strange situation too. First off, ever since I've had my car it's surged to 2k or above upon starting it up, and then gradually goes down to 800, but then jumps between that and 1500 or 2000 randomly from normal. I checked all of my hoses and lines for leaks and can't seem to locate any. But recently I killed my battery overnight by leaving a domelight on and when I jumped it, the idle was fluctuating between 200 and 800, nearly dying. And it did die on me at a stopsign. A day has gone by (I haven't fully recharged the battery, I know I should) and it doesn't do it that drasticly anymore. It hovers around 700-800 or so, but I still get the surge as always. Sorry for all of this mumbo jumbo but I just want to be specific. I'm going to check all of those other things suggested here first and hopefully that will fix my surge. But could a weak battery really cause that diving idle?

Aaron

 

[tsi_turboawd]

Use a volt meter/multimeter to test your battery.

Could a bad IAC cause idle surge? or it not sitting properly and needs to be adjusted?

 

[92TALONAWD]

My car did the same thing for a while and the wire for the air temp (I think) on the throttle body came loose. The single wire on the back by the firewall. Fixed this and no more surge when cold.

Good luck Matt

 

[Gooberlog]

Originally posted by tsi_turboawd
Use a volt meter/multimeter to test your battery.

Could a bad IAC cause idle surge? or it not sitting properly and needs to be adjusted?

This is where i would have picked up after checking for leaks , tps, intercooler hoses etc. The IAC is your Idle Air Control, if basicly controls your idle, chances of it not being installed right are slim, and i don't think that there are any adjustments, but i would check the voltage to the IAC, but you could have an intermitent problem. Good luck. I would determine that that's what's wrong before buying a new sensor, i'm sure its expensive.
Gooberlog

 

[ModInProgress]

my freind has an auto tsi, 92 his would surge after he would pull up to my house when it was in park. i just tightened, turned down the idle screw and it went away, it only did it when the fan kicked on cus the fan automatically makes the motor idle higher but then it was idleing so high and it was gettin too much air and not enuf fuel at like 2100 rpms, try turning the idle down. hope it works, jason