Rough, loping idle...

K

Kilgore Trout

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#1

• Nov 29, 2006

• #1

My Cobra idles rough.

So far I have tried:
-seafoam
-changed plugs
-cleaned MAF
-reset PCM

Is it normal for there to be a bit of roughness in the idle?

Other things I am planning to try are:
-new fuel filter
-new x-pipe because I think my cats are clogged

But maybe the lope is just normal for the engine???

 

timeless2

Vi Veri Veni Versum Vicus Vici

Admin Dude

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Nov 29, 2006

#2

• Nov 29, 2006

• #2

It's not throwing any codes, right?

Why would your cats be clogged with the low mileage you have?

 

U

Uncle Meat

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Nov 29, 2006

#3

• Nov 29, 2006

• #3

These engines do not lope with the stock cams. Should purr like a kitten. Haven't heard of problems with the stock cats getting clogged. This rough idle happens warm or cold at idle (approximately 750RPM's)?

U.M.

 

K

Kilgore Trout

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#4

• Nov 29, 2006

• #4

Clogged cats seems to be a pretty common issue people post about for 03s...

The check engine light is not on.

It does it when warm.

 

U

Uncle Meat

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Nov 29, 2006

#5

• Nov 29, 2006

• #5

Kilgore Trout said:

Clogged cats seems to be a pretty common issue people post about for 03s...

The check engine light is not on.

It does it when warm.

Click to expand...

I've rarely read about clogged stock cats on a STOCK '03. Seems if they were clogged though the down stream O2's would be throwing a code.

U.M.

 

K

Kilgore Trout

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#6

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What do you think is causing my idle issue?

 

68torinogt

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Mar 21, 2006

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Welcome my son, welcome to the machine

Nov 29, 2006

#7

• Nov 29, 2006

• #7

View attachment 420652

 

S

STRTRENEGADE354

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#8

• Nov 29, 2006

• #8

What did you use to clean the maf?
And what plugs and what gap do you have them at.

 

K

Kilgore Trout

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#9

• Nov 29, 2006

• #9

I used quick drying electrical contact cleaner spray to clean MAF.

I installed Motorcraft AGSF-12FM1 gapped at .035

 

K

Kilgore Trout

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#10

• Nov 29, 2006

• #10

68torinogt said:

View attachment 420634

Click to expand...

You know this is a tech forum right? Keep that kind of "crap" in talk...

 

K

Kilgore Trout

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#11

• Nov 29, 2006

• #11

Well, I just recleaned the MAF and also cleaned the IAC plus I again reset the PCM.

The idle still sucks

Next up is a fuel filter, if that does not correct it I have a feeling it is gonna be something expensive to fix... $$$

 

U

Uncle Meat

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Nov 30, 2006

#12

• Nov 30, 2006

• #12

If you just recet the PCM, make sure you give the car at least a half-dozen drive cycles and see if it clears up. Did it idle rough prior to repacing the plugs?

U.M.

 

K

Kilgore Trout

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#13

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• #13

Yes, the idle is exactly the same as it was before I started doing things to attempt to correct it. Nothing I have done has had any effect on the rough idle.

However, driving in to work this morning in the cold rain with the a/c on the idle was much smoother. Perhaps the fuel trims are re-learning to smooth it out. I will keep a close eye on it for the next few days.

 

U

Uncle Meat

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#14

• Nov 30, 2006

• #14

I say give it a few more drive cycles before taking it in for professional help.

U.M.

 

K

Kilgore Trout

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#15

• Nov 30, 2006

• #15

Yeah, until I get my tax return professional help is not really an option... Christmas is killing me this year

Thanks for the advice sir

 

68torinogt

Hey guys, guess what--I have a bi-pass!!!

Mar 21, 2006

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Welcome my son, welcome to the machine

Nov 30, 2006

#16

• Nov 30, 2006

• #16

im sorry,


i suggest putting a scanner on it and pull off sensor info,

we have a snap-on scanner and it gives tons of good helpful info.

 

M

midlifecrisis99cobra

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Nov 30, 2006

#17

• Nov 30, 2006

• #17

My 99 has done the same thing since day 1. Slightly rough idle at about 750-800 rpm when warm. Idles smoothly about 850-900 when cold. Gets better for about 15 minutes after changing plugs then goes back to same old deal.

I occasionally wonder about an injector/coil issue. Doesn't seem to be generating any codes.