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360DakotaPwr
01-18-2012, 12:24 PM
I have a mildly built 360 in my Dakota that I just recently tuned with SCT. I am having trouble keeping it from bogging down on deceleration before the truck eventually stops rolling. Once the truck stops rolling it bounces to the set idle speed and runs fine. I found idle speed in the Advantage software and upped it to 800 on idle and 850 in gear. This has helped a lot, but it still does not decelerate and idle like it should. Does anyone know what area of the Advantage software to play with to smooth out my transisition from driving to idle?

cbra
01-18-2012, 01:15 PM
Put some miles on it. I had the same problem. The new tune resets the IAC and it needs time to learn your engine. I put some miles on mine and it works ok now.

grapejuice1998
01-18-2012, 02:02 PM
You can also crack the t/b blades open just a little more at idle and that will help. Just a little bit though.

98Dak408
01-18-2012, 03:50 PM
Put some miles on it. I had the same problem. The new tune resets the IAC and it needs time to learn your engine. I put some miles on mine and it works ok now.


You can also crack the t/b blades open just a little more at idle and that will help. Just a little bit though.

I'm thinking IAC counts too. Opening the throttle plates allows for more air to pass and the IAC motor will not spend so much time hunting trying to get the idle right.

This procedure has always worked for me, which is along the same lines as what grapejuice1998 is telling you. http://www.bionicdodge.com/Download/Adjusting%20the%20idle%20for%20a%20Magnum.pdf

360DakotaPwr
01-18-2012, 07:03 PM
Thanks, thats a good little write up. The guy who wrote my sct tune bumped the idle up to 800 in the tune file. Should I leave it there or put it back to stock and adjust the throttle plates as described?

98Dak408
01-18-2012, 07:16 PM
I'd try adjusting it with the idle at 800.

grapejuice1998
01-18-2012, 08:30 PM
800 is good, because that will also help to keep the misfire codes from popping up. (hopefully)

360DakotaPwr
01-18-2012, 11:53 PM
Ok, I was getting random injector malfunction codes before the sct tune running on the stock brain box file, but not anymore. No misfire codes so far. I do keep getting a code for the ignotion coil since I put an MSD one on.

grapejuice1998
01-19-2012, 02:15 PM
Ok, I was getting random injector malfunction codes before the sct tune running on the stock brain box file, but not anymore. No misfire codes so far. I do keep getting a code for the ignotion coil since I put an MSD one on.

P0351 no doubt. You will need to add the Tach Adapter to cure that one, but it's no big deal if you don't.

360DakotaPwr
01-19-2012, 03:42 PM
Yep, thats the code. Do you know which tach adapter I would use?

360DakotaPwr
01-19-2012, 03:53 PM
I'm thinking IAC counts too. Opening the throttle plates allows for more air to pass and the IAC motor will not spend so much time hunting trying to get the idle right.

This procedure has always worked for me, which is along the same lines as what grapejuice1998 is telling you. http://www.bionicdodge.com/Download/Adjusting%20the%20idle%20for%20a%20Magnum.pdf

Ok, I used my scanner to look at IAC counts. It was 40-50 before I tried anything and still bogging down on deceleration. I tried the 1st. procedure outlined in the pdf document. It didn't work. The motor idled up to 2000 rpm after I pulled my finger off the IAC hole. I set the throtte screw back to where I started.

I used the scanner to reset the IAC position. The counts went up to 130. I ran a IAC test to be sure it is working properly and everything checked out. I then tried the procedure again and I set my idle at 800 through the throttle body plates. The IAC hardly opens now because most of the air flow is through the throttle plates. It runs at 800 rpm, still boggs a little on deceleration, but returns to 800 quicker now. My IAC counts are still around 90 though, not within the spec of the write up.

Thanks for the help.

grapejuice1998
01-19-2012, 04:04 PM
Ok, I used my scanner to look at IAC counts. It was 40-50 before I tried anything and still bogging down on deceleration. I tried the 1st. procedure outlined in the pdf document. It didn't work. The motor idled up to 2000 rpm after I pulled my finger off the IAC hole. I set the throtte screw back to where I started.

I used the scanner to reset the IAC position. The counts went up to 130. I ran a IAC test to be sure it is working properly and everything checked out. I then tried the procedure again and I set my idle at 800 through the throttle body plates. The IAC hardly opens now because most of the air flow is through the throttle plates. It runs at 800 rpm, still boggs a little on deceleration, but returns to 800 quicker now. My IAC counts are still around 90 though, not within the spec of the write up.

Thanks for the help.

Have you tried cleaning the IAC sensor and/or the passages in the t/b?

As for the tach adapter, I don't know the p/n.

360DakotaPwr
01-19-2012, 04:08 PM
Have you tried cleaning the IAC sensor and/or the passages in the t/b?

Yea, its all super clean.

98Dak408
01-19-2012, 08:14 PM
I believe this is the tach adapter: http://www.msdignition.com/Products/Accessories/Tach_Adapters/8910_-_Tach_Adapter.aspx

98Dak408
01-19-2012, 08:19 PM
Ok, I used my scanner to look at IAC counts. It was 40-50 before I tried anything and still bogging down on deceleration. I tried the 1st. procedure outlined in the pdf document. It didn't work. The motor idled up to 2000 rpm after I pulled my finger off the IAC hole. I set the throtte screw back to where I started.

I used the scanner to reset the IAC position. The counts went up to 130. I ran a IAC test to be sure it is working properly and everything checked out. I then tried the procedure again and I set my idle at 800 through the throttle body plates. The IAC hardly opens now because most of the air flow is through the throttle plates. It runs at 800 rpm, still boggs a little on deceleration, but returns to 800 quicker now. My IAC counts are still around 90 though, not within the spec of the write up.

Thanks for the help.
The engine will flare up when you remove your finger and then settle back down. If it doesn't settle back down, turn the engine off and then restart it. It should be fine.

The further the throttle plates are open, the smaller your IAC counts will be. You can't set the IAC counts with the scanner. You can only read what they are. Sometimes it takes a few attempts setting them to get it right. But as Alan stated, and as the procedure states, opening the throttle plates should help, and will lower you IAC counts.

360DakotaPwr
01-20-2012, 12:51 AM
Thanks for all the info. I got it pretty close now. IAC counts are still around 90 but it is not bogging so bad anymore. RPM's are set at 800, it will fall to 600 ish worst case right before the truck comes to a stop and then bounces right back to 800.

98Dak408
01-20-2012, 01:04 AM
Thanks for all the info. I got it pretty close now. IAC counts are still around 90 but it is not bogging so bad anymore. RPM's are set at 800, it will fall to 600 ish worst case right before the truck comes to a stop and then bounces right back to 800. I'd give it another shot opening the throttle plates a little more. You can always more it back if needed.

360DakotaPwr
02-04-2012, 03:01 PM
In the Adavntage software for playing with Idle Speed, there is a column labeled steps. The guy who tuned my truck changed values in this column. Does anyone know how it works?

Filthy Filbert
02-04-2012, 06:16 PM
for the P0351, I would only worry about it if you have to pass an 'OBD-II scan" for emissions testing. the code is soft code and will not trip your CEL. no need to go spend more money just to stop the computer from freaking out by not seeing the resistance of the stock coil. it does not change how the truck will drive at all, the adapter only stops the code from getting stored into your PCM.

again, not an issue at all unless you have to pass an emissions test where they plug into your OBD-II port and read any codes.

Five9Dak
02-04-2012, 07:10 PM
p0351 will pass plug in emissions. It is a waste of money to bother correcting it.

White Turbo
02-04-2012, 07:27 PM
p0351 will pass plug in emissions. It is a waste of money to bother correcting it.

Same here...
I passed OBDII emissions in WA. state with the P0351 code.

Filthy Filbert
02-04-2012, 08:58 PM
Well, there you go!

I don't know what they look for in emissions tests. never had to do it myself, thank god I live in a state that's not totally communist yet!

I just figured that if you had ANY trouble codes, they would require you to fix them to pass inspection.

360DakotaPwr
02-07-2012, 02:15 AM
Thanks everyone. Luckily no emission test here yet.

I put in a MSD Tach Adapter that 98Dak408 posted earlier and it took care of the coil code. No big deal like you guys said, but its fixed :)

Now what about this question I posted earlier: In the Adavntage software for playing with Idle Speed, there is a column labeled steps. The guy who tuned my truck changed values in this column. Does anyone know how it works?

AngryTaco
03-28-2012, 07:42 PM
Now what about this question I posted earlier: In the Adavntage software for playing with Idle Speed, there is a column labeled steps. The guy who tuned my truck changed values in this column. Does anyone know how it works?


I too am interested in this. I havent touched my values but it does idle right 650rpm where I want it, for now