Stoplight Surgeing??????????

[BluThnder99]

I have notice in the last couple of days my car surges at stoplights, does anybody have any idea what is causing this?

 

[sgramer]

Ideas

How long have you had the plenum, K&N, and the cold air kit. You may need to clean your MAF, because of the K&N oil. You may need to reset the computer because, of the plenum. Do you have a bend in front of the MAF, because of the CAI, if so you may need to change that.


Scott

 

[BluThnder99]

How long have you had the plenum, K&N, and the cold air kit. You may need to clean your MAF, because of the K&N oil. You may need to reset the computer because, of the plenum. Do you have a bend in front of the MAF, because of the CAI, if so you may need to change that.


Scott

The MAF is stock and I haven't cleaned the K&N yet.

 

[daver01]

my car did something similar to this earlier in the year. it would kinda 'hunt' for idle when i was stopped at a light, but sounded more like it does when the a/c is running. (idle going up & down)

may not be exactly the problem u are having; but after i cleaned the iac with carb cleaner, the prob. went away. worth a shot; only takes a min.

 

[jrc_03_gt]

do you have underdrive pulleys?

 

[BluThnder99]

do you have underdrive pulleys?

No underdrive pulleys but I'll try cleaning my IAC though thanks fo rthe tip.

 

[SRMobile]

Try disconnecting the battery for 15 mins and let the computer relearn everything.

 

[big o car 4.6]

What is the IAC

 

[big o car 4.6]

do you have underdrive pulleys?

and what would that have to do with it

 

[SRMobile]

Idle Air Control... Apparently its a comon problem on the stangs and usualy needs cleaning replacing after a good amount of millage.

Symptoms include stalling and having to give a little gas in order to keep the engine going while idling.

 

[JonJon]

I don't know if it would be the IAC... but if yours starts to idle fine, well I'll go check mine out.

 

[StangIt #1]

Idle Air Control... Apparently its a comon problem on the stangs and usualy needs cleaning replacing after a good amount of millage.

Symptoms include stalling and having to give a little gas in order to keep the engine going while idling.

...and, if your '97 GT still has the factory-issue IAC, it's probably time for it to go bad. The one on my '98 went last year, so be prepared to drop around $70-$80 (can't remember for sure) for a new one from Ford. The IAC on our GT's ('96-'98) is a little aluminum piece with at least 1 vacuum hose stuck into it and some type of black plastic "valve" looking piece on the side of it. You can find it bolted just in front of your upper plenum. BTW, cleaning the IAC is only a temporary fix, because the valve spring inside of the unit is probably worn out.

 

[SRMobile]

and what would that have to do with it

Under drive pulleys do exacly as the name states. It underdrives the accesories on the engine in order to free up some power. I did this with my last car and when at a stop light, my lights would dim, AC would slow down and the idle would be quite low.

 

[JonJon]

Under drive pulleys do exacly as the name states. It underdrives the accesories on the engine in order to free up some power. I did this with my last car and when at a stop light, my lights would dim, AC would slow down and the idle would be quite low.

But did you idle surge a lot?
Mine will go from 1000 to 500 to 700, and repeat. I assume the thread starter has the same problem.

 

[SRMobile]

My regular idle in my other car before I put in the UDP was just under 1000 and would work its way down slowly to 900ish. After I did the change it would idle around 900 and go as low as 700. It wouldnt idle as smooth as it did before but it never stalled.

 

[SRMobile]

Come to think of it, is it possible that its just the compressor cycling ?

 

[ForPointSex]

Clear or replace your IAC. Here's a picture if you don't know where it's at. http://www.geocities.com/joop1987/iac.jpg