Idle Surge problem! Can't figure it out and I've searched!!!!!

[1997_GST]

Okay, so i have a 97 GST that i did a 5-speed swap on. The car runs, I drove it from Mansfield, TX to Electra, TX, about a 2.5 hour drive,. The car has a idle surge. And it's annoying and makes me mad!!! It had a SAFC hooked up to it but i removed it to see if that would change anything and it didn't. I've tried different ecus and still does it.

The surge is like between 1100 rpm and 1800 rpm... and if i give it gas it revs fine but after i let off the throttle it sticks at like 2500 rpms for a split second then goes back to the surging...

If i drive the car and like barley hold it in 1st gear it like changes the throttle on it's own...but does fine while normal driving at highway speeds...

ANY HELP WOULD BE APPRECIATED AND REMEMBER I DID SEARCH ON THIS AND COULDN'T FIND ANYTHING THAT MATCHED EXACTLY MY PROBLEM....

THANKS!!!!!

 

[agentorange313]

here you go:

DSMISC Automotive (New ISC Supplier)

DSM THrottle Bodys

EXTREME PSI : Your #1 Source for In Stock Performance Parts - OEM Idle Speed Controller (ISC): Mitsubishi Eclipse 06/90 - 99

as you can tell the cheapest is TB.com but new for 136 cant be beat.

Extremem sells oem but they are 300....its an easy choice.

goodluck

 

[liquidz28]

a moving isc does not mean the valve is functioning. which is why i re described what you already mentioned. and a good/bad isc will always have carbon deposits on it.

ps. biss asjutment will not drop engine speed on a surging motor

yes, but a "good" isc can be hindered by chunks of carbon build-up...

 

[AG 305]

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

+ (insert random exagerated number here!!!) this helped my idle surge issue ALOT!

 

[empie1]

Do your self a favor and ditch the FIAV and emmissions all together. Best thing i ever did to my car.

 

[Absit]

+ (insert random exagerated number here!!!) this helped my idle surge issue ALOT!

The only thing that link doesn't cover, that ended up being half the answer to my surge, was the throttle cable adjustment. Everyone overlooks that..

 

[AG 305]

The only thing that link doesn't cover, that ended up being half the answer to my surge, was the throttle cable adjustment. Everyone overlooks that..

hell yeah. it should cover that... but i know to check that if somethings up with my idle

 

[Toyboxx]

My car is doing the same thing, I assume it's something I touched while doing my EVO III 16G Swap (Intercooler Piping) ### it wasn't doing it before. Or it could just be a coincident that my ISC went out at the same time. I'll report back soon what it was.

 

[Absit]

hell yeah. it should cover that... but i know to check that if somethings up with my idle

Oh it's not a matter of HOW to check it, that's easy. It's the simple fact that you NEED to check it, and the reason behind it.

 

[AG 305]

Oh it's not a matter of HOW to check it, that's easy. It's the simple fact that you NEED to check it, and the reason behind it.

thats what im saying i know TO check my throttle if somethings up

 

[blueboost68]

If you go to the local pull a part.Look on the 95 to 99 Nissan Maxima same iac
just has the plug on the side

 

[1997_GST]

Ya so when i took my old isc apart i found the whole inside was like glued together from carbon build up and crap from sitting so long i guess... But i have 2 extra to try out and see if it fixes my idle surge!!

 

[1997_GST]

Sorry for the late late delay... but my problem did turn out to be my isc... thank all of you for your help!!!

 

[zanderson]

I had a similar problem. IAC. or MAF are common problems. Try cleaning the MAF but make sure to get the right cleaner some say DO NOT USE MITSUBISHI. otherwise if those dont work I noticed that if you have you TPS down too low it will cause an idle surge.

 

[Wobet]

Alright this is something noone has considered which is a good sign in the 2g world(since it's biggest downfall was the infamous crankwalk)

Now, my 2g nt spyder had an idle surge. And I checked everything you guys mentioned previous to my response. But one day. I cold started and BAM! Belt pops off the harmonic balancer. And it hits me. My "idle surge" was actualy my crank walking drastically.

 

[1997_GST]

Well replacing the isc worked and solved the problem for me.

 

[Wobet]

Good stuff. I'm the unlucky 2g 4g64 guy

 

[1997_GST]

my motor did crankwalk but on the previous owner that is a buddy of mine and he had the motor completly rebuilt and it was automatic and something was wrong with it so i converted it to 5 spd and now it runs good!

 

[Wobet]

my motor did crankwalk but on the previous owner that is a buddy of mine and he had the motor completly rebuilt and it was automatic and something was wrong with it so i converted it to 5 spd and now it runs good!

Nice . Stick is the way to go