Aug 7, 2015, 02:31 PM
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- Dodge Dodge Ram 2nd Gen How to Replace Idle Air Control (IAC) Valve
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DIY How to clean the IAC
Record Breaker
Joined: May 2008
Posts: 1,174
Likes: 1
From: North TX
Could be the brushes in the alternator are going bad.
When you left the key in and disconnected the battery for the 10 minutes did you leave the key on as you reconnected or had you turned the key off before reconnection?
When you left the key in and disconnected the battery for the 10 minutes did you leave the key on as you reconnected or had you turned the key off before reconnection?
Professional
Joined: Jan 2012
Posts: 146
Likes: 0
I believe I left the ignition key in the on position when I reconnected the negative cable of the battery. If that is the incorrect thing to do then I can certainly disconnect the battery again and do the 10 min drain with the ignition in the on position and then make sure it is in the off position when I reconnect the negative cable of the battery.
Let me know,
Jason
Let me know,
Jason
Professional
Joined: Jan 2012
Posts: 146
Likes: 0
Ok, I did as you suggested. It was raining today in IL. I let the Van sit for about 3 hours with the battery disconnected and the Key on . Its 6:21Pm now and I just finished reconnecting the negative cable of the battery.
As I went to start the Van the engine did not want to start with out me stepping on the gas pedal. When it did start it was running rough and would not stay running without me staying on the gas pedal.
All lights were out on the dash except for the check gauges light. As I increased the RPM on the engine I noticed that the light on the odometer when out. What was interesting as I turned the blower switch on and off it turned on and off with it. Also the gas gauge was not showing the proper reading for the amount of fuel in the tank. It was showing full instead of 1/2 tank like it did yesterday.
So unless you have some other ideas. All I have left is recheck all the ground straps, remove and clean the PCM mounts and use contact clearner on the PCM plugs. Check the complete alternator cable for any bare wire or possible ground, and then all that will be left is the PCM which is where I suspect the problem really is.
Jason
As I went to start the Van the engine did not want to start with out me stepping on the gas pedal. When it did start it was running rough and would not stay running without me staying on the gas pedal.
All lights were out on the dash except for the check gauges light. As I increased the RPM on the engine I noticed that the light on the odometer when out. What was interesting as I turned the blower switch on and off it turned on and off with it. Also the gas gauge was not showing the proper reading for the amount of fuel in the tank. It was showing full instead of 1/2 tank like it did yesterday.
So unless you have some other ideas. All I have left is recheck all the ground straps, remove and clean the PCM mounts and use contact clearner on the PCM plugs. Check the complete alternator cable for any bare wire or possible ground, and then all that will be left is the PCM which is where I suspect the problem really is.
Jason
Record Breaker
Joined: May 2008
Posts: 1,174
Likes: 1
From: North TX
Sorry that it did not help. Your diagnosis is on the right track. I would add to double check the connection on the insturment clustor as well before you replace the PCM. May or maynot help but worth a try first.
Professional
Joined: Jan 2012
Posts: 146
Likes: 0
One last thing to add to the list is the battery temp sensor. Its located in the battery tray and communicates with the PCM Voltage Regulator and will step up or down the charging circuit based on battery temp.
Jason
Jason
Registered User
Joined: Aug 2010
Posts: 8
Likes: 0
From: California
I replaced my IAC today after getting some idle speed problems in park or drive at stop lights. I did not find this thread till after (dang it).
The IAC we got from Autozone had the pintal all the way 'in' the housing.
I turned it clockwise to 'somewhat' match the length of the removed IAC.
Should I have left it in the 'in' position? Or did I do the right thing in matching the removed one.
The reason I'm asking, is that the idle is now around 500 rpm's and it does not want to start unless I give it some push on the gas pedal. It will stall out until it gets near warm up.
I did drive it at 40 mph for 20 minutes after warm up per the instructions that came with the new IAC.
Should I do the reset with the neg battery cable removed?
(the truck drives fine once warmed up, it does go to about 600 rpm with A/C on.)
Thanks for any help and appreciate that this thread is still kicking some butts.
The IAC we got from Autozone had the pintal all the way 'in' the housing.
I turned it clockwise to 'somewhat' match the length of the removed IAC.
Should I have left it in the 'in' position? Or did I do the right thing in matching the removed one.
The reason I'm asking, is that the idle is now around 500 rpm's and it does not want to start unless I give it some push on the gas pedal. It will stall out until it gets near warm up.
I did drive it at 40 mph for 20 minutes after warm up per the instructions that came with the new IAC.
Should I do the reset with the neg battery cable removed?
(the truck drives fine once warmed up, it does go to about 600 rpm with A/C on.)
Thanks for any help and appreciate that this thread is still kicking some butts.
Record Breaker
Joined: May 2008
Posts: 1,174
Likes: 1
From: North TX
This is from the same member whom started this thread.
Originally Posted by Stev
Per the advise of another Dodge forum on the internet, a DCX service tech, to me to give the TB the finger. After that all the problems went away. Well, this is a finger treatment you give to the IAC with the engine running at idle. Placing your index finger over the air-inlet port to the IAC on the TB, carefully and slowly choke off the air going into the port until the engine nearly stalls out. I did this several times since the IAC was pulsating. At the last time, I totally choked off the IAC until the engine stalled. This made the IAC to draw all the way back within it’s sensor housing. (NOTE: this is done only with the IAC mounted on the TB.)
The next step is critical. Take the negative battery terminal off for 2 mins. DO NOT touch the key until the 2 mins have passed.!!!! Now, turn the key off and reconnect the negative battery cable. This resets not only the PCM, but the other sensors for the TB.
Now, the final step was to turn the key back on for 5 seconds prior to a full start crank over. The IAC when it had stalled the engine from running drew all the way back in travel. Upon restarting, and waiting for the five seconds, I heard two distinct cracking noises from the IAC in movement as it went into it's position.
The next step is critical. Take the negative battery terminal off for 2 mins. DO NOT touch the key until the 2 mins have passed.!!!! Now, turn the key off and reconnect the negative battery cable. This resets not only the PCM, but the other sensors for the TB.
Now, the final step was to turn the key back on for 5 seconds prior to a full start crank over. The IAC when it had stalled the engine from running drew all the way back in travel. Upon restarting, and waiting for the five seconds, I heard two distinct cracking noises from the IAC in movement as it went into it's position.