rough idle HELP!!!

[03CobraCCC]

my car shudders at idle (750RPM) once every 2-2.5 seconds...doesnt stall or die just feel a shudder in the seat and flooring.....this is also without A/C on or any other accessories at almost all operation temps.........

is possible spark blowout?

or what?

Any help is greatly appreciated!!!

 

[Cobra'03]

Are you new to the car? They can have an erratic idle, but it should not shudder. Doubt spark blowout is problem. Is it better with A/C on or at 1000 rpm? Does it run well the rest of the time?

 

[mike79]

I think thats normal.

 

[03 COBRA SB]

Originally posted by 03CobraCCC
my car shudders at idle (750RPM) once every 2-2.5 seconds...doesnt stall or die just feel a shudder in the seat and flooring.....this is also without A/C on or any other accessories at almost all operation temps.........

is possible spark blowout?

or what?

Any help is greatly appreciated!!!

it is called a 4 cams, should be standard for stock 03 Cobra's

 

[KOTH]

With the A/C on idle is smooth at 750 rpms.

With the A/C off the idle is slightly rough at 550-650 rpms.

 

[Twinturbo Ranger]

My car does the same thing. It took me a couple weeks to notice it because the A/C was always on. At first I thought the K&N caused it, but I believe it is just a low idle. If you give it a little throttle to were it idles like the A/C is on it is smooth as silk. I also drove my friends Mach 1 yesterday and it idles a little higher than my Cobra and has no problems. I'm going to reset the idle and see how she does.
Thanks Mike

 

[rskdsk]

That is normal for 2003 cobra ... so is the ticking, stalling, vib etc... Get used to it, you only paid 35k for the car.

 

[Killer Cobra]

Originally posted by rskdsk
That is normal for 2003 cobra ... so is the ticking, stalling, vib etc... Get used to it, you only paid 35k for the car.

Damn!!!

 

[SAcobra427]

My car does the exact same thing. I stopped by the dealer to talk to a tech about it and he told me there is nothing that can be done about it. I have no idea if this guy knew much about the 03's or not, they have sold quite a few Cobras through there though ???

 

[wmccormick]

rough idle

My dealer told me Ford was going to have a new EEC flash that would solve the problem in a couple of weeks.

 

[T's Blk03]

Mines been in 2x's for this and a few other minor things as well as a couple of major things. They have tested everything on the car, flashed the computer (for stalling) and it still idles rough with the A/C off. A/C on and it's perfect, never stalls either. I'm guessing the idle is just too low when the A/C is off and the computer just cannot catch it before it stalls. I've learned to live with it for now but when colder temps roll around and I'm not using the A/C 24/7 then I may have it looked at again or take a stab at adjusting the IAC or TPS my self.

 

[05 Roush]

Same Here

I just took mine in for the same problem. Idles perfectly with the air on at 750RPM. When the air is off, it has a rough idle at 550RPM.

The local dealer called SVT and they told them to replace the spark plugs. Didn't fix the problem (although a free tuneup doesn't hurt). Dealer just said "This is normal". So why then does it idle smooth with the air on????

Hope SVT gets a TSB out soon.

11K and quickly rising.:beer:

 

[pgordon]

Another car with the rough low idle. Smooths out with ac on. No problem as long as it does not stall.

 

[KenCobra03]

My Cobra has a weird idle also.The dealer said
it checks out ok.
How do you get a 13.01et bone stock???
Help me out,here.
Launch or shifting or what?
See my sig. Ken

 

[BLK_03]

KenCobra03,

Work on that 60 foot brother. I was 60 footing 2.2x's over and over and hovering at 13.3 in the 1/4. Finally got a 2.0x 60 foot and into the 12's!!

Oh yeah, lopy idle here too. Unless A/C is on, then she purrs. It has stalled on me 3 times in 4,000 miles. No correlation with the stalling. Once when warm idling in a fast food line, once while cold after backing out of the driveway...

 

[03CobraCCC]

got the 13.01 w/out powershifting either....so i know with my current spare removed and air silencer and maybe a 2.0 60ft and some powershifting, i think high 12's are very very doable...it was a decent track night..only got 2 runs in tho, and first 2 ever on this car....and trust me im a rookie...

try feathering the clutch from 2000-2300RPM...

practice,practice, practice...........plus weather conditions have a huge effect on S/C motors.....id say try again in the fall when humidity get down....