Lots Of Problems, Plz Help..

GTpowerwithin

Member
Jul 10, 2012
50
2
18
Hey guys new to the mustang era, an love it so far sorry if I posted in the wrong area.. Anyways I have even having problems with my car.. 97' mustang GT 4.6, I had to replace the coolant sensor; didn't know it would run so bad.. I fixed that, anyways.. I've changed the IAC valve, from oreillys, I've changed the TPS, and also cleaned off the MAF, which I was really really careful with on the wires
When I'm driving down the highway at cruising speeds, my Rpms will jump twice and my foot will just be barely on the gas.. It weird, or when I'm at a stop light it wants to jump on me and wanna go, and it does it in park but just revs up..

Mods: 3:73 gears, I guess shift kit, (automatic) flow master exhaust, straight pipe, and SCT tuner, which I'm still learning to use, I can only use a strategy tune.. But Idont have the USB part with it to hook up to a computer..
 
  • Sponsors (?)


FWIIW, almost all cars have two throttle return springs. Sometimes one is a traditional coil spring that's easily seen. The 2nd spring maybe a "coil" spring wrapped around the butterfly shaft.

Other times there are two coil spring units one inside the other.

Regardless, the throttle MUST close fully when the driver takes his/her foot off of the gas. The throttle return spring has to have enough force to do this.

While you are at it, check for vacuum leaks. Change the PVC valve.

Here's some more information on how to trouble shoot idle issues.

http://www.allfordmustangs.com/foru...-dieing-idle-idling-rough-14.html#post2260649
 
Wmburns I checked my throttle cables I found the one that is on top, and found a black plastic one that is on the bottom that hooks to the butterfly, but when I did so, it made the butterfly open up extremely almost open throttle.. What Can I do?

ImageUploadedByTapatalk1344796979.899607.jpg


And also i can't find the PCV valve I mean there is one on the valve cover but the oil cap, but that sucker wouldn't come off
 
Wmburns I checked my throttle cables I found the one that is on top, and found a black plastic one that is on the bottom that hooks to the butterfly, but when I did so, it made the butterfly open up extremely almost open throttle.. What Can I do?

ImageUploadedByTapatalk1344796979.899607.jpg


And also i can't find the PCV valve I mean there is one on the valve cover but the oil cap, but that sucker wouldn't come off

The spring is return spring #1, check where the butterfly shaft goes through the throttle body. There should be one on the side coiled around the butterfly shaft. The thing with the black clip is the cruise control cable. That shouldn't have any effect, but you can leave it disconnected and see if that helps the problem.

The PCV is on the valve cover and should be grey. They are twist lock. If you use an adjustable wrench, or large pair of pliers, grab the base (it should be cut so that you can grip it) and untwist it....then it will just pop out.

EDIT

I just looked back at the picture, and return spring #2 is in the picture. It is the blue spring right below the throttle set screw.
 
This is why I always come to SN first with any questions, Burns is always a great help along with Trinity GT and others.
 
  • Like
Reactions: 1 user
Did you read through the information regarding how to trouble shoot idle/IAC issues? If so, what were the results of the test called out?

Did you confirm the fuses?

Have you replaced the PVC valve?

You know the ODDS still favor a vacuum leak.

Thanks everyone for the kind words. Sometimes a vote of confidence is nice to hear.
 
  • Like
Reactions: 1 user
I checked all fuses under hood, and under dash.. All were good? Which ones should I really look at? I could replace them just to say I did..

and which one is the PVC valve? There is one on the driver side valve cover, that is next to the oil cap, and then there is one on the other valve cover passenger side that pops right off..
 
Just wondering why you would replace a fuse instead of "test" it? Or how about taking it out and looking at it? A simple VOM can determine if a fuse is good or not. Much cheaper to test than replace.

For the SOHC 4.6 the PVC valve is on the right (passenger) side.

There is no valve on the left hand side. It's a crank case vent intake line. The air supply comes from the upper intake so that all air entering the motor is metered.
 
Ok so what fuses do I check? My coolant gauge doesn't work, but barely does..

And my TB is humming as well sorry for all the questions this is all new to me..

And thanks for all your help WMburns I just need u on speed dial lol