Idle Surge FIX

[seskyrabart]

as the rules say , we should post if we fix a problem and how we fixed it, im doing that here. I dont recommend it but it worked for me.

I read alot about IDLE surge problems, when your RPM is jumping back and forth 600-2000 and so on..
I read it usually is the IAC/ ISC motor that goes bad. Well that was true for me. What i did , start the car and as soon as it was somewhere near the regular RPM range , 800-900
i took the wiring off the IAC motor.
The engine light is still on but there is no IDLE problem. This is a temporary thing iv done till i get money to buy a new motor or till i find a used one. Its been about 3-4 weeks and the car hasnt given any problems. Starts fine. Runs Fine. Doesnt stall.
hope this helps


if i am wrong please correct me
thanks.

btw, i have a 96 spyder GS. 46g4 motor that has a Different IAC motor.

 

[BK85]

My 97 Spyder GS has the same TB as yours and the same problem, (the ISC connector is a flat one not square). That has to be one they use on the 2.4L 4G64 motors. I also have the same idle surge. I saw your other post and tried the trick of disconnection the ISC when it was idling right. It works. Now my question is have you had any problems running with the connector disconnected?

BK85

 

[logans dad]

I put a 1g TB on my 98 GSX and you can see mods in profile but any way it ran fine when I first put it on. I did have to adjust the biss a little. Then I unhooked battery to work on it and when I put it back together I had the dreaded idle surge. checked iac and it checked OK. Took off TB and rechecked tps setting it was just a little off so set it and put it back on and same thing, surge. I'm 49 and went to what I call my shade tree mechanical skills and got a 1/4 inch socket wrench and a 9mm socket and got the hard to see screw and other out side screw just loose enough to turn tps and moved it a little and a nice high idle came back. Had to loosen the throttle stop in back of TB and adjusted idle down to 900 as I like it a little high for more oil pressure when clutch is in. I don't know what tps is set at now but been driving car for 2 days and its still fine. Just thought this information might be helpful if every thing checks OK Play with the tps, and you don't have to take off TB to set it. Use a 1/4 inch rachet and you can get to the inside screw.

 

[UNDER_PRESSURE]

Try messin with the idle screw make just a minor adjustment to it while it's on and that should fix the problem in most cases, or else take a closer look at the Idle Air Control Valve (IACV).

 

[logans dad]

I tried that and it didnt help, My problem was the tps setting.

 

[sobutter]

i have a 96 rs, i tried cleaning out the throttle body and that didn't work.. do you guys suggest i buy the ohmeter(or however you spell it) and check to see if my TPS is the problem?

i'm idling at 1100-1200 right now, occasionally it will drop to the 700-800 range.. one time, in the 2 months i've been driving this car, when i stopped at a light, my car was idling at 3000!! so i turned off and restarted, and it went back down... not only do i idle high, but I also have that bucking problem, which makes it tougher to drive in traffic it's embarassing idling slowly past cars in bumper to bumper traffic, then all of a sudden it looks like you jammed on your breaks for no reason.

 

[logans dad]

Sobutter, Yes, buy a ohmmeter and check every thing and read my post how I just got a 1/4 ratchet and loosened bolts a little and turned Tps just a hair and it idles fine now. this might not fix you up but worth a try. I should go out and check my tps setting and see what it reads now. I know its off from the book but with mods I think it needs to be set different.

Just do an idle search or idle serge also, Lots of good info here. A year ago I didnt know what a bov was .

 

[kevint427]

Have you thrown a check engine light? If so, do you know what code it is? I am having somewhat more of a dramatic problem on my 2g GST. I threw a code and it was a TPS Malfunction. If it is a malfunction there is no adjustment that can fix it. Something internally took a crap. A new TPS is really not that much. I got one from dealer for $95. A little pricey but they promised me a life time warranty on the part. Autozone wanted $93 for a 3 year warranty. Along with Pep - Boys (Cars hate them, people do to!), and Kragen. The TPS was also special order from all three of these places. Paying the 2 extra dollars for same day equipment and a lifetime warranty is pretty much worth it in my book.

Also, you may have a daisy chain of problems. For example, my car at idle will surge. Here is why: At idle the Idle Switch is depressed. The TB is allowing too much air to enter the motor due to Idle Speed Control being opened completly during start up and stuck there. The O2 sensor will then detect too much air and the ECU will send more fuel to compensate. With more air & fuel entering the motor the RPM's will increase and at 1500 the ECU cuts the fuel untill reaching 1200 rpm where the whole loop will start over again. Now in my situation, the TPS went bad before it threw a code. With a malfunctioning TPS the car may not idle at all in some circumstances. The Idle Speed Control tried to componsate for it and after not helping the ECU does not know what is going on. AFter too much working for a period of time the ISC died. In the mist of these two problems the car was running extremely rich due to added fuel. The EGR Valve had no idea what was going on and also died. After not running right for a week, the first week I have owned the car mind you, the ECU threw another CE light, cylindar 3 misfire. Which after looking at the brand new plugs with blackened tips I checked the injectors. All fine O-rings and all untill reaching cylindar three. O-ring rotted and almost non-existant, and the injector did not look to be working. Which it was not. Double checked the cylindar 3 plug compared to the #2 plug and came to the realization that #2 was A LOT darker than 3. After replacing all injectors and O-rings, an ISC, a TPS, and an EGR Valve, not to mention the little things (fuel filter, spark plugs and wires, OBD2 scanner). The car now runs perfect. Not a problem. So I hope I provided you with some idea's. A big help for me was this link:

http://www.dsm.org/how-tos/tttt/tttt3.html

Hope this helps in some way!