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Fired the Mustang up idle problem


SLOWLX

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Cant figure why its idleing like this I cleaned the Mass Sensor and Idle control valve and checked No vacum Leaks Rpm keep jumpin up and down and its seems when its warmed up it runs fine(at the end of the video) Any ideas? Only way i could post a video

http://mail.aol.com/35412-111/aol-6/en-us/mail/get-attachment.aspx?uid=73460&folder=Inbox&partId=1&saveAs=IMG_0058.MOV

Mods include

 

gt40 motor

DSS Stroker kit

crane roller rockers

b303 cam

underdrive pullies

bbk cold air intake

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Can't play the video but I'm guessing bad MAF or hard to find leak. What MAF is on the car?

 

Stock But i did notice it sounds like the air filter is trying to suck in air but it always stalls out out when you first start it up

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Stock But i did notice it sounds like the air filter is trying to suck in air but it always stalls out out when you first start it up

 

The only spare MAF I have is calibrated for 24 pound injectors. Maybe someone has a stock one laying around you could swap in. May not be the issue but its super easy to rule out that way. A replacement IAC is pretty cheap if you want to start throwing parts at it.

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Correct me if I'm wrong but why would a throttle bodied vehicle ever need the idle adjusted? Wouldn't that be a band aid of sorts? I was under the impression you never have to adjust idle on a throttle body. Idle issues would be something else, sensor, etc.
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Correct me if I'm wrong but why would a throttle bodied vehicle ever need the idle adjusted? Wouldn't that be a band aid of sorts? I was under the impression you never have to adjust idle on a throttle body. Idle issues would be something else, sensor, etc.

 

Agreeg-IMHO

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Correct me if I'm wrong but why would a throttle bodied vehicle ever need the idle adjusted? Wouldn't that be a band aid of sorts? I was under the impression you never have to adjust idle on a throttle body. Idle issues would be something else, sensor, etc.

Larger cams often dictate a higher idle speed just as they would in a carbureted application. In the case of an EFI car, or specifically this type where it's still a mechanical adjustment, not controlled by the ECU. You simply turn the stop screw in to set it to the desired RPM but you need to then readjust the TPS (people seem to forget the latter).

 

A B303 isn't really that big of a cam but it does have a pretty narrow lobe separation causing enough overlap that I find the engine to be more drivable with a bump to about 850 RPM idle speed.

 

That said, I doubt the idle speed itself is his issue in this case, just that the TPS may have been improperly set along the line somewhere.

Edited by twistedfocus
phrasing
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i adjusted the idle speed and it seems it worked but it only acts up when the engine is cold so Ill have to see Tomorrow

B303 cam is decent one i mean you can hear it at idle and it lopes pretty good Im happy with it

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i adjusted the idle speed and it seems it worked but it only acts up when the engine is cold so Ill have to see Tomorrow

B303 cam is decent one i mean you can hear it at idle and it lopes pretty good Im happy with it

 

But all of the other guys said that wouldn't work...........

How many of you guys giving advice have ever owned a Fox body Mustang? Just curious.

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Correct me if I'm wrong but why would a throttle bodied vehicle ever need the idle adjusted? Wouldn't that be a band aid of sorts? I was under the impression you never have to adjust idle on a throttle body. Idle issues would be something else, sensor, etc.

 

I wonder why they come with the ability to adjust them then?

How is it a band aid if you adjust idle speed slightly and it keeps it from stalling?

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But all of the other guys said that wouldn't work...........

How many of you guys giving advice have ever owned a Fox body Mustang? Just curious.

 

I wonder why they come with the ability to adjust them then?

How is it a band aid if you adjust idle speed slightly and it keeps it from stalling?

can't provide actual answers, retorts to assuming we don't know what we're doing.

 

I'm not looking to argue. I asked a question. It's a band aid considering it shouldn't need messed with and there's an underlying problem, obviously.

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How many of you guys giving advice have ever owned a Fox body Mustang? Just curious.

I have had a couple. They only ran on jack stands and unicorn pee, so I may not be a good technical resource.

:gabe:

 

Seriously though. It's hard to diagnose a car via Internet so the more people brainstorming the merrier I say. Wrong or right it gets you thinking critically.

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