I need help ASAP
#1
I need help ASAP
My problem is about my (IAC) Idle Air Control valve. I thought i read that you can figure out if it's bad by disconnecting the plug to it, and see if your idle changes in rpms which it kinda did, but i guess i was wrong what i read. Now my check engine light is on and i disconnected my negative side of the battery, and pluged it back in and put the terminal back on now it is still on. Do you think i hurt anything or i just need to go get a new (IAC) valve.
#2
You should be able to reset the codes on any OBDII equipped vechile by unhooking the battery for a couple minutes. Try re connecting your IAC valve unhooking the battery for 5 min or so, Then hook it back up and start the truck. If the check engine light comes back on get a OBDII tester. Either buy one (about 75.00) or free testing at pep boys (or similar). You may get a code (19) loss of PCM power. Dont worry about it. Chect to see if you have a code (12) Idle Speed Control motor or Air Bypass not controlling idle properly (generally idle too low) - ISC or a code (13)O) ISC did not respond properly (extends to touch throttle then retracts for KOEO) - ISC
(R) Idle Speed Control motor or Air Bypass not controlling idle properly (generally idle too high)
(M) ISC sticking, open ITS circuit or TP sticking
Good luck.
(R) Idle Speed Control motor or Air Bypass not controlling idle properly (generally idle too high)
(M) ISC sticking, open ITS circuit or TP sticking
Good luck.
#3
Originally Posted by planefixer
You may get a code (19) loss of PCM power. Dont worry about it. Chect to see if you have a code (12) Idle Speed Control motor or Air Bypass not controlling idle properly (generally idle too low) - ISC or a code (13)O) ISC did not respond properly
#4
the whole reason i unhooked it was becasue of this. But when i unhooked the plug and drove around the block they droped almost emediately. What is normal for my rmps to drop or stay up for 5 or so seconds then go down.
The first problem, is when i shift around 2800-3000 rpms. While im shifting from 1st to 2nd when i push in the clutch to shift to 2nd. My rpms don't drop until like four seconds pass. Is this normal. Because my Dads F-350 diesel 5sp dully and his F-150 5sp his rpms drop almost emedietly when he pushes in the clutch. Which mine i have to wait 5 seconds or else i get a jerk when i let out the cluch out. Just want to know if this is normal.
Second probelm, Iv'e been having a squell in my front end for about a month. What happened was sometimes when i push in the clutch my rpms will drop to like 200. Then rise up to my idle speed which is 900 rpms. That led to me thinking it was my idler pully so i changed that and still same squell and same drop in rpms when i push in my clutch. So I don't know what it could be.
Please help Thanks
The first problem, is when i shift around 2800-3000 rpms. While im shifting from 1st to 2nd when i push in the clutch to shift to 2nd. My rpms don't drop until like four seconds pass. Is this normal. Because my Dads F-350 diesel 5sp dully and his F-150 5sp his rpms drop almost emedietly when he pushes in the clutch. Which mine i have to wait 5 seconds or else i get a jerk when i let out the cluch out. Just want to know if this is normal.
Second probelm, Iv'e been having a squell in my front end for about a month. What happened was sometimes when i push in the clutch my rpms will drop to like 200. Then rise up to my idle speed which is 900 rpms. That led to me thinking it was my idler pully so i changed that and still same squell and same drop in rpms when i push in my clutch. So I don't know what it could be.
Please help Thanks
#5
Ok Check the connector for debris cracks or broken or bent pins. Also check for wire damage.
1st the 2800 shift. Have you checked you pedal? Some times in the cold they will freeze up a little. or your throttle spring {on the throttle} could have gotten caught on somthing or just worn and snapped {although i have never one broken}.
Also it sounds like it could be the IAC or the EGR.
2 the Squeal. Is it when your turning {power steering}, Defrost / A-C, Subs,Head lights{alternator} But the most important thing to check is the Belt. is it worn or SUPER smooth? If it slips it squeals.
The thing about this is.... You may spend over $100 to replace "random parts" When it costs less for a corect Diag from a dealership. Some times they wont charge you. Then you will know Better of what is realy goin on. The WDS {Fords little and VERRY EXPENSIVE "code reader"} can check what it is. And say what to do. Also it cna program certain aspects of the vehicle to fit your needs. And you can controll certain things with it to test them. Not like a Midas "Snap-on" code reader.
In other words IF you want this to be quick and less painfull try the dealership.
1st the 2800 shift. Have you checked you pedal? Some times in the cold they will freeze up a little. or your throttle spring {on the throttle} could have gotten caught on somthing or just worn and snapped {although i have never one broken}.
Also it sounds like it could be the IAC or the EGR.
2 the Squeal. Is it when your turning {power steering}, Defrost / A-C, Subs,Head lights{alternator} But the most important thing to check is the Belt. is it worn or SUPER smooth? If it slips it squeals.
The thing about this is.... You may spend over $100 to replace "random parts" When it costs less for a corect Diag from a dealership. Some times they wont charge you. Then you will know Better of what is realy goin on. The WDS {Fords little and VERRY EXPENSIVE "code reader"} can check what it is. And say what to do. Also it cna program certain aspects of the vehicle to fit your needs. And you can controll certain things with it to test them. Not like a Midas "Snap-on" code reader.
In other words IF you want this to be quick and less painfull try the dealership.
#6
Originally Posted by htvfd460stx
Ok Check the connector for debris cracks or broken or bent pins. Also check for wire damage.
1st the 2800 shift. Have you checked you pedal? Some times in the cold they will freeze up a little. or your throttle spring {on the throttle} could have gotten caught on somthing or just worn and snapped {although i have never one broken}.
Also it sounds like it could be the IAC or the EGR.
2 the Squeal. Is it when your turning {power steering}, Defrost / A-C, Subs,Head lights{alternator} But the most important thing to check is the Belt. is it worn or SUPER smooth? If it slips it squeals.
The thing about this is.... You may spend over $100 to replace "random parts" When it costs less for a corect Diag from a dealership. Some times they wont charge you. Then you will know Better of what is realy goin on. The WDS {Fords little and VERRY EXPENSIVE "code reader"} can check what it is. And say what to do. Also it cna program certain aspects of the vehicle to fit your needs. And you can controll certain things with it to test them. Not like a Midas "Snap-on" code reader.
In other words IF you want this to be quick and less painfull try the dealership.
1st the 2800 shift. Have you checked you pedal? Some times in the cold they will freeze up a little. or your throttle spring {on the throttle} could have gotten caught on somthing or just worn and snapped {although i have never one broken}.
Also it sounds like it could be the IAC or the EGR.
2 the Squeal. Is it when your turning {power steering}, Defrost / A-C, Subs,Head lights{alternator} But the most important thing to check is the Belt. is it worn or SUPER smooth? If it slips it squeals.
The thing about this is.... You may spend over $100 to replace "random parts" When it costs less for a corect Diag from a dealership. Some times they wont charge you. Then you will know Better of what is realy goin on. The WDS {Fords little and VERRY EXPENSIVE "code reader"} can check what it is. And say what to do. Also it cna program certain aspects of the vehicle to fit your needs. And you can controll certain things with it to test them. Not like a Midas "Snap-on" code reader.
In other words IF you want this to be quick and less painfull try the dealership.
#7
Originally Posted by lilk67
What is normal for my rmps to drop or stay up for 5 or so seconds then go down.
Dashpot prevents the engine vacuum from increasing too rapidly during shifting and decels. Sharp vacuum spikes can cause corresponding hydrocarbon spikes on the emission test.
So, yes, it can be "normal" to see your RPM hang up somewhat during shifts and during deceleration with the clutch disengaged. The question really is, "How much is normal?"
How much and how long the RPM is sustained will vary with different years and different engines. If you're seeing something that hangs at 1000~1500, roughly speaking, I wouldn't worry about it. If it is hanging for more than a second at 2000 or higher, then you probably have a malfunction of some kind.
Of course, you will need to be sure that the engine is up to operating temperature (off of high idle) before checking the above.
Last edited by V8 Level II; 03-19-2007 at 07:12 AM.
#8
Originally Posted by rwenzing
The IAC is commanded to be partially open during part throttle conditions - this is called "pre-position" mode. When you let off the throttle, the IAC continues to bleed air past the throttle plate and this holds the RPM up for a short time. Then the additional RPM should decay over a few seconds and allow the engine to drop slowly down closer to idle speed. This RPM decay over time is called the "dashpot function".
Dashpot prevents the engine vacuum from increasing too rapidly during shifting and decels. Sharp vacuum spikes can cause corresponding hydrocarbon spikes on the emission test.
So, yes, it can be "normal" to see your RPM hang up somewhat during shifts. The question really is, "How much is normal?"
How much and how long the RPM is sustained will vary with different years and different engines. If you're seeing something that hangs at 1000~1500, roughly speaking, I wouldn't worry about it. If it is hanging for more than a second at 2000 or higher, then you probably have a malfunction of some kind.
Of course, you will need to be sure that the engine is up to operating temperature (off of high idle) before checking the above.
Dashpot prevents the engine vacuum from increasing too rapidly during shifting and decels. Sharp vacuum spikes can cause corresponding hydrocarbon spikes on the emission test.
So, yes, it can be "normal" to see your RPM hang up somewhat during shifts. The question really is, "How much is normal?"
How much and how long the RPM is sustained will vary with different years and different engines. If you're seeing something that hangs at 1000~1500, roughly speaking, I wouldn't worry about it. If it is hanging for more than a second at 2000 or higher, then you probably have a malfunction of some kind.
Of course, you will need to be sure that the engine is up to operating temperature (off of high idle) before checking the above.
#9
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