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  • SN95 4.6L Mustang Tech

IAC valve didn.t helped. Help!!!

  • Thread starter Thread starter MexStanger
  • Start date Start date Sep 29, 2005
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MexStanger

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Jul 7, 2005
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Monterrey,Mexico
Sep 29, 2005
#1
  • Sep 29, 2005
  • #1
After reading a month ago or so about other Mustang owners having the idle problem and supposedly fixing it changing the IAC valve I made the same thing and replaced the valve. For my surprise the problem wasn't solved and I already spended a couple hundreds trying to fix this problem.

Any suggestions on how to fix this problem.

The car starts rumbling mopst of times when you make sudden brake and the car stops.
And also frequently when you are halted like on a red light.


I will appreciate any help
Thanks
Heriberto Lopez O.
 

ultrashock2112

New Member
Jul 13, 2005
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Vancouver, Canada
Sep 29, 2005
#2
  • Sep 29, 2005
  • #2
MexStanger said:
After reading a month ago or so about other Mustang owners having the idle problem and supposedly fixing it changing the IAC valve I made the same thing and replaced the valve. For my surprise the problem wasn't solved and I already spended a couple hundreds trying to fix this problem.

Any suggestions on how to fix this problem.

The car starts rumbling mopst of times when you make sudden brake and the car stops.
And also frequently when you are halted like on a red light.


I will appreciate any help
Thanks
Heriberto Lopez O.
Click to expand...

Is your check engine light on? Did you get codes pulled? I'd check all the usual things like fuel filter, plugs, wires (if applicable), air filter, vacuum leaks, battery (old one might not hold much charge).
 

53BigDog

Active Member
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Sep 29, 2005
#3
  • Sep 29, 2005
  • #3
ultrashock2112 said:
Is your check engine light on? Did you get codes pulled? I'd check all the usual things like fuel filter, plugs, wires (if applicable), air filter, vacuum leaks, battery (old one might not hold much charge).
Click to expand...

I would start there a loose spark plug or brittle wire can screw everything up. In addition you could alsway check your TPS (Throttle Position Sensor)
 
M

MexStanger

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Sep 30, 2005
#4
  • Sep 30, 2005
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Tps

where can I find a picture of the TPS

Thanks
 

RandyStinchcomb

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#5
  • Sep 30, 2005
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we allmost NEVER see problems out of the TPS, so don't even bother wth it. my ? is where did you get the IAC from, a Ford dealer or a parts store?
 
M

MexStanger

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Oct 1, 2005
#6
  • Oct 1, 2005
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answer

the mechanic bought it from a parts store.


Thanks
 

mrvax

Stay thirsty my friends
Founding Member
Nov 29, 1999
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Oct 1, 2005
#7
  • Oct 1, 2005
  • #7
Can't you have the shop diagnose the problem? I'd hate to see you keep trying things and costing you $ and not solving the problem.

Do you have a K&N air filter? Did you clean it recently? For a last shot here, list all the info about your car and any mods made. See my sig for example.
 
M

MexStanger

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Oct 4, 2005
#8
  • Oct 4, 2005
  • #8
thanks

i'll have the guy at the shop check the info from the computer. I didn't do it yet since when I took it out from the shop the check engine was off. Until today the check engine appeared again.

My stang is completely stock.
I have done some repairs on it:
Alternator (repaired)
Radiator (new)
Rear axle shaft (new)

I'll appreciate any help you can provide me, since it's very frustating to spend money on it and the problem still being there.
Today after parking the car and instantly trying to restart it to park it elsewhere, the car didn't started, and after 20 minutes aprox. I tried it again and the car started normally as if nothing happened. Is the second time that does this, the first was about 2 months ago.

Do you have an email address where I can contact you more often?

Best Regards
Heriberto
 

RandyStinchcomb

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Oct 5, 2005
#9
  • Oct 5, 2005
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MexStanger said:
the mechanic bought it from a parts store.


Thanks
Click to expand...


thers your first problem, Never by Electronics for Fords from parts stores. always go-to the dealer for these parts. the factory stuff might be more $$ but there designed to work on your model, make and year car/truck, where the aftermarket makes a part work for a much broader range of vehicles.
 

mity2

I like Pro3 and all I got was this crappy CT.
Jul 24, 2003
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Oct 5, 2005
#10
  • Oct 5, 2005
  • #10
have u pulled any code out???
 

todd4566

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#11
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Top this: Monday went outside to start the Mach. Starts up, then dies. Start it again.. starts and dies. Start a 3rd time & hold the gas down.. stays alive only if given gas. In this condition, I was able to back the car out, and drive to the rear of my work parking lot (the car stalls between shifts since I don't have a third foot to hold the gas down a bit ) By the time I drive the car in 1st gear to the back of the parking lot, it's now idling fine. WTF. I immediately drove the car to Ford and dumped it. They can't duplicate the problem, and think it was a stuck IAC or something. OK... it's getting fixed for 2nd gear grind and a few other things, but looks like I'm SOL on the stalling for the moment. Emailed the service mgr this morning demanding a second look, but we'll see.
 
K

Kilgore Trout

Fried or Broiled ?
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#12
  • Oct 5, 2005
  • #12
todd4566 said:
Top this: Monday went outside to start the Mach. Starts up, then dies. Start it again.. starts and dies. Start a 3rd time & hold the gas down.. stays alive only if given gas. In this condition, I was able to back the car out, and drive to the rear of my work parking lot (the car stalls between shifts since I don't have a third foot to hold the gas down a bit ) By the time I drive the car in 1st gear to the back of the parking lot, it's now idling fine. WTF. I immediately drove the car to Ford and dumped it. They can't duplicate the problem, and think it was a stuck IAC or something. OK... it's getting fixed for 2nd gear grind and a few other things, but looks like I'm SOL on the stalling for the moment. Emailed the service mgr this morning demanding a second look, but we'll see.
Click to expand...
What you describe is 99% likely to be stuck IAC valve... It is intermittent. Make them f'n replace it under warranty...
 

todd4566

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Kilgore Trout said:
What you describe is 99% likely to be stuck IAC valve... It is intermittent. Make them f'n replace it under warranty...
Click to expand...

I agree the IAC seems to be responsible, but since they can't duplicate it they haven't offered to replace anything in regards to that. Any recommendations on how to demand a new IAC? Sux.. I hear the Mach's IAC in within the manifold, so it's not as simple as me buying a $40 part and removing two bolts like the Gt.
 

timeless2

Vi Veri Veni Versum Vicus Vici
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Oct 5, 2005
#14
  • Oct 5, 2005
  • #14
todd4566 said:
I agree the IAC seems to be responsible, but since they can't duplicate it they haven't offered to replace anything in regards to that. Any recommendations on how to demand a new IAC? Sux.. I hear the Mach's IAC in within the manifold, so it's not as simple as me buying a $40 part and removing two bolts like the Gt.
Click to expand...

The IAC is a VERY tempermental part that has plagued these cars for some time. It's no doubt they will have a tough time duplicating it. It's almost as if the car senses it's guts are going to be poked and it acts fine while getting serviced/repaired.
 

todd4566

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#15
  • Oct 5, 2005
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git-it-83 said:
The IAC is a VERY tempermental part that has plagued these cars for some time. It's no doubt they will have a tough time duplicating it. It's almost as if the car senses it's guts are going to be poked and it acts fine while getting serviced/repaired.
Click to expand...

Yeah.. sux. I just left a message on the svc mgr's cell that I want the IAC looked at again, but I'm sure it'll check out ok.
 

RandyStinchcomb

New Member
May 25, 2005
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Oct 5, 2005
#16
  • Oct 5, 2005
  • #16
todd4566 said:
Top this: Monday went outside to start the Mach. Starts up, then dies. Start it again.. starts and dies. Start a 3rd time & hold the gas down.. stays alive only if given gas. In this condition, I was able to back the car out, and drive to the rear of my work parking lot (the car stalls between shifts since I don't have a third foot to hold the gas down a bit ) By the time I drive the car in 1st gear to the back of the parking lot, it's now idling fine. WTF. I immediately drove the car to Ford and dumped it. They can't duplicate the problem, and think it was a stuck IAC or something. OK... it's getting fixed for 2nd gear grind and a few other things, but looks like I'm SOL on the stalling for the moment. Emailed the service mgr this morning demanding a second look, but we'll see.
Click to expand...



depending on the build date, it could also be a problem wth the FPR sensor as there was a design change effective 12/6/02 the old problematic ones have a stamp # of f8cf-pf972-bh and were replaced by the new (improved) designed part # 3R3Z-9F972-AA
 

todd4566

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#17
  • Oct 5, 2005
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RandyStinchcomb said:
depending on the build date, it could also be a problem wth the FPR sensor as there was a design change effective 12/6/02 the old problematic ones have a stamp # of f8cf-pf972-bh and were replaced by the new (improved) designed part # 3R3Z-9F972-AA
Click to expand...

Build date for me was 11/22/02, so I have the crapper part. Forgive me.. what does FPR sensor, and can is it easily replaced? I have a feeling I'll be nickel and diming some parts myself.
 

RandyStinchcomb

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todd4566 said:
Build date for me was 11/22/02, so I have the crapper part. Forgive me.. what does FPR sensor, and can is it easily replaced? I have a feeling I'll be nickel and diming some parts myself.
Click to expand...



FPR = Fuel Pressure Rail sensor, its a little square black sensor bolted down on the fuel rail, we sell the hell outta' them. price is @$50.00
 

todd4566

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#19
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RandyStinchcomb said:
FPR = Fuel Pressure Rail sensor, its a little square black sensor bolted down on the fuel rail, we sell the hell outta' them. price is @$50.00
Click to expand...

Is the part easily accessible without removing much? I'll replace it myself if I'm unsuccessful in getting Ford to do more work.

*It's not my intention to hijack your thread MexStanger - hopefully this info is of value to you as well.
 

RandyStinchcomb

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#20
  • Oct 5, 2005
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todd4566 said:
Is the part easily accessible without removing much? I'll replace it myself if I'm unsuccessful in getting Ford to do more work.

*It's not my intention to hijack your thread MexStanger - hopefully this info is of value to you as well.
Click to expand...


yeah, I dont think it's to bad. might have to re-move the shaker asbly but that should be all
 
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