Idle Surge, very bad, need help!!!

xhypno · 05-27-2002, 06:42 PM

Ok here is the problem. On May 6, I bought a 1994 ES Talon with the 2.0l 4g63 motor. It has 65k on it, and is in very good condition. About one week ago, the check engine light went on, and when at an idle the rpms jump about 300-700, and when the clutch is in or when not in gear (slowing down) the same surge appears.
I connected an ohm meter to the data port and came up with a code 43. Which is for the egr system. I tested the thermo valve sensors, all working. I test the vacum to it, good. I figured all that is left is the egr valve. I removed the valve, and it was fauled bad, alot of carbon deposits. I used carb cleaner and a wire brush to clean it. I then vacum checked the valve. It seemed to be working.
At this point I thought every thing should be fine. I put the valve back in and started the car. It was fine. But after a 10 min drive later that day, it started again, but this time with no check engine light.
I have checked every sensor under the hood twice with the ohm meter and still can't find another problem.

Does anyone have a suggestion?????

Any help will be appreciated!!!!! Thank you Philip

xhypno · 05-31-2002, 09:18 AM

I just blocked of the egr valve, with the info from the vaq's. I am about to go try it, will let everyone know.

xhypno · 05-31-2002, 11:13 AM

Ok, it worked to a point!!! Does anyone think it could be a problem, with either my fuel system or vacum, or maybe my plugs and wires.

L2RTSiAWD · 05-31-2002, 11:46 AM

You think that's bad. after drving aroung for a while my idle will start fine but eventually it will idle at 1900rpm and stay that way unless I leave the car off overnight. Try stopping at every light and your car idling at 2k. not fun when I stop somewhere and get back in the car I can't even put it in reverse the idle is so high so I have to start the car in reverse.

red91GSX · 05-31-2002, 12:21 PM

Hey XHYPNO, check out this site - www.dsm.org or go to http://www.dsm.org/how-tos/tttt/index.html this is some really good info on what's called IDLE SURGE. It's really indepth and I think I have the same prob. It deals with a part of your car called the ISC - Idle Speed Control connected to your throttle body and the worst part is your ECU won't give a code for it, ergo your dealer 99/100 times won't find it either. Check it out.

HondaHunter2002 · 05-31-2002, 04:36 PM

clean your throttle body and get a new tps(throttle position sensor)
go to vfaq.com to get the procedure to clean the throttle body..
my idle surge was horrible now it only does it for about 20 seconds when i start the car and than it's gone

Think · 06-04-2002, 10:07 PM

Yeah, sounds like the throttle is all screwed up, especially in your case, Mutted. I would do what HondaHunter said, maybe even get a new throttle assembly if cleaning it all out doesn't work.

xhypno · 06-04-2002, 10:13 PM

No cleaning it didn't work. I am gonna go to a junk yard tomorrow and pull a new one (used one). I call them, they have a few dsm with the 4G63 there, so they should have one.

eclipsegs96 · 09-01-2002, 06:12 AM

i would also look into the Idle Speed Control, that may solve the prolem alone, but you never know, worth a shot

DarksideMS · 09-02-2002, 03:01 AM

Hey,
i had the exact same problem with my (non-turbo) DSM, i took it to my local dealer here's what they told me.

O2 sensor no longer functioning properly
Throttle position sensor adjusted out of range
Idle air control motor not working

then they told me it would be about $1200 (canadian funds) to get the problem fixed.

Anyone have any ideas?? it seems like $1200 is pretty steep to get the car running normally... does anyone know of a way to re-adjust these parts?

any help greatly appreciated

-Darkside

xhypno · 09-02-2002, 09:43 AM

go to an autoparts place, and for 80dollars us get a new o2 sensor. Then put it in, and clean the ISC and TPS with carbarator cleaner. It should stop.

DarksideMS · 09-02-2002, 11:22 AM

thanks a lot!!! i'd rather spend $120(cdn) than $1200!!!

Darkside

xhypno · 09-02-2002, 11:53 AM

yeah I know what ya mean!!

91eklipsegs · 09-02-2002, 04:55 PM

On the throttle body there is an idle set screw that has a tendacy to fall out if there isnt a cap on it. The screw is right by where the throttle body bolts to the intake manifold, it is in a little hole towards the front of the car on the tb. Go to the factory and get a new idle set screw and put it in, once you have it in and adjusted how you want it, cover the screw hole woth some silicone and that will keep thescrew from falling out again.

BBoyTSi · 10-04-2002, 07:14 AM

Good morning DSM'ers

I have gotten idle surge for sometime now, and if you are talon digest reader or irc.dsm.org chatter, u've probably seen me yapping about my idle surge.

car started to idle surge with CEL on for about month or two now. with some serious procrastination, and lack of funds.

here's how the car acts;
cold morning, starts up fine, idles fine, 5 min after drive to work, at a stop sign, starts to idle surge from 800rpm to 1300rpm. continue to work, some days the car will kill when clutch is depressed (pretty dangerous because power steering cuts out), but some days it will idle high or really really low (250rpm). it gets quiet annoying.

here's what i've done;
1. checked the vacuum of the intake with vfaq's homemaid vacuum tester.
2. went to ahpproduct.com's owner Chris to get it diagnosed, but his OBD2 diagnostic computer was broken, but he thought it was the map sensor (many peeps at talon digest disagreed on this), he also checked the idle speed screw but that was fine.
3. i know my o2's good because my a/f gauge is bouncing back and forth normally, and at WOT, it reads nice green rich.
4. i also know my ISC is working (maybe partially) since when i pop on the air conditioner, the idle jumps to 1200rpm and stays there.
5. my exhaust don't smell rich at all.

here are my questions:
1. any dsm'er in my area have a pocket logger or any cheap way to pull engine codes?
2. how would cleaning the isc and throttle with the carb cleaner help? i'd like to try this probably today, but probably wont' get time.
3. would bad battery terminal cause this?
4. would MAP sensor (manifold air pressure only on 2Gs) cause this since ECU is reading wrong manifold pressure?
5. a person told me that he had same problem but his throttle cable was too tight, how can i check for this?
6. maybe spart plugs? (mine are all new NGK's properly gapped and have magnecore 8.5mm something wires maybe 5k miles on these)
7. maybe there's a leak i cannot detect with the homemaid vacuum tester?

any help would be greatly appreciated!
thanks guys.

dsmtuners ROCK!

xhypno · 10-04-2002, 07:55 AM

Ok, either the ISC is working, or it isn't.

Does the Idle Surge right after the car has started, or after it has been run?

Did it come on all of a sudden, or gradually?

If it surges right after you turn the car on, you most likely need a new TPS, if it surges only after it has run for a while, your ISC is either Fouled of going.

To clean the Throttle Body and ISC, you should remove the Throttle body and ISC, then spray them with carb cleaner untill all deposits are off of them (about 2 hours of work).

Your car is listed as a TSI. TSI equals Turbo, which means you have a Mass Air Flow Sensor (MAF or MAS). Only the 2g NT's have the MAP sensor, because they don't use a MAS. There ecu's adjust the fuel according to throttle position, manifold pressure, and the voltage coming from the o2 sensor. While 1g's and All Turbos adjust fuel by the amount of air entering the engine through the MAS, and the voltage coming from the o2 sensor.

If you have removed all of the honeycombs, or opened flow around the upper honeycomb (through the bottom) too much, it will cause this idle surge, because the engine is running lean (more air is getting in then the engine accounts for), and then the voltage at the o2 sensor is wrong and the ecu is scrambling to fix it. Giving you an eratic idle.

Let me know how things go.

xhypno

BBoyTSi · 10-04-2002, 08:04 AM

car idles perfectly fine when car's started. So you think its the ISC? There is a map sensor on the 2g turbos. i have looked up the part on partznet.com and it names it MAP sensor..... i dunno if this could cause idle surge b/c of the ecu not being able to read correct pressure?
i did remove the lower section of the honey comb (i was stupid), but car an perfectly fine for months, i'm talking like 10 months here.
I have never had eratic idle with the small piece of the honey comb removed. so i highly doubt its that.
I have a friend with a code reader (i found this out today, i'm gonna beat that kid), so i'll keep you guys in touch on what happens with the car.

keep these suggestions comming and enlighten the newbie please

thanks guys.

dsmtuners rock!

BBoyTSi · 10-04-2002, 08:05 AM

also, if ISC is dead dead, u gotta buy a new one right? from what i understand, these things are major dough.

:/

gst_cruisr · 11-05-2002, 10:00 AM

okay...so i was reading the info above and i don't know what exactly everyone is talking about, but i think i have the same problem. so... what happens is that when my car has been sitting (or after everytime i turn it off), i go to start it up and my idle skys to about 2500 or 3000. then as i start to drive it, the idle lowers, but everytime i have my foot on the clutch or when i have it in neutral, the idle surges restlessly. also, when i have the car in gear, i can feel the car jump back and forth, parallel to the "idle surge". oh yea.. and once the car has warmed up... the surging quits... another weird thing is that my heat gauge is extremely high... i have no idea what it is... so if anyone can suggest something..please.. it'd be greatly appreciated...thanks..

xhypno · 11-05-2002, 05:19 PM

New info, The idle surge can be 3 things.... The TPS, O2 sensor, or a bad exhuast leak.

I change my TPS and it went away, then it came back about 3months later, and I checked my TPS and it was fine. I looked at my exhuast manifold and found 3 hugh cracks that weren't there before, Those cracks cause the same surge. I put headers on and the problem stoped.

xhypno

drewstealth94 · 11-05-2002, 10:59 PM

Well i also got idle problems on my 93 tsi. But mine are a little different. I had bad idle surge but i adjusted my idle screw and now it doen't really surge anymore. But the problem is that my idle is never the same. I set it to be around 900. Then sometimes it will be like 1100 or 750. It is never what i set it to. But it doesn't really surge much. The problem is when it sets it self to low(around 750 and lower)and then when i turn the lights on and press the clutch it dies because it goes to around 500 or a little lower. I checked the o ring on the idle screw and it is dead even with the top of the screw. Is it supposed to be out further so no air can pass or is it supposed to be even.

DamionGST · 11-05-2002, 11:23 PM

Ok I also have an idle problem, but my problem is all the time. From the time I start my car it idles at 2k until after about 10 minutes of driving then it starts to surge from 2500 to 1500 until I turn it off.

gst_cruisr · 11-07-2002, 09:23 AM

So i don't know what an ISC or TPS is. please explain... i have to fix this problem before winter comes around... my heat gauge is still kinda weird... :o