Hanging idle
#21
03-18-2017, 11:57 PM
It shows true rpm (1240-1280 normally) with the target of 752. I need to look at info again because it is hanging longer since I added the headers. I also noticed that the wideband was fluctuating more while it was idled up.
If you can think of a list of stats to watch that might help, please let me know. I'll write down what it's showing to make sure my memory isn't fixing numbers for me.
If you can think of a list of stats to watch that might help, please let me know. I'll write down what it's showing to make sure my memory isn't fixing numbers for me.
#22
03-19-2017, 09:05 AM
#23
03-19-2017, 11:00 PM
Slacker, 8 am (6 here) and your just starting your coffee 
.
Here are the PIDS from when it's not acting up:
Normal idle, not moving...
Coolant volts-1.1, temp 194° F
. Here are the PIDS from when it's not acting up:
Normal idle, not moving...
Coolant volts-1.1, temp 194° F
TPS volts- .76, position- 0%
Min TPS- .76, Spark advance- 4 to 6
Upstream O2- .1 to .8, downstream- .6 to .75
Short term trim- -5.7 to -9.6, long term- -13.9
Target IAC- 20, actual- 20
Desired idle (this never changes)- 752, actual- 736
Load value %- 6 to 7
Notes from normal operation; Sitting still, rev up to 3200ish rpms and hold for a few moments. IAC settled in at 90 steps. Let off throttle, idle falls smooth to 736, IAC falls smooth with idle to 20.
Notes when acting up (moving only tonight, won't act up sitting still); After holding steady throttle at 3200 rpms, all info within expected ranges (IAC 90, increased timing, slower O2 response but in same range as idle ECT...) Take out of gear and release throttle. IAC jump 10 to 20 steps higher (100 to 110) then falls to 60 to 68 (target and actual) as idle falls to 1280. At this point the IAC adjusts to maintain 1280 rpms, to the point of going wide open (190 steps) if I put the truck back into gear and apply brake to pull the idle down. This carries on for anywhere from 5 to 45 seconds, then it falls smoothly to normal idle.
Just like taking an intermittent problem to a shop, it won't act up when it's suppose to. The idle will normally hang when sitting still in the same fashion as it did moving today.
I'm thinking about setting up the neutral safety on a switch to see if that makes any difference. It is just grounded out since I did the manual swap. I'm not sure why it would make a difference now when it ran fine like that for a few years before the 408, but I'm out of ideas. I also need to switch back to the stock tune (if the it will run on it still) and see if that changes anything since I'm not sure how Hemifever sets up his trans delete tune. Guess I should try Ryan's last tune too since he hasn't done the trans delete. They were all acting the same the last time I tried them.
Min TPS- .76, Spark advance- 4 to 6
Upstream O2- .1 to .8, downstream- .6 to .75
Short term trim- -5.7 to -9.6, long term- -13.9
Target IAC- 20, actual- 20
Desired idle (this never changes)- 752, actual- 736
Load value %- 6 to 7
Notes from normal operation; Sitting still, rev up to 3200ish rpms and hold for a few moments. IAC settled in at 90 steps. Let off throttle, idle falls smooth to 736, IAC falls smooth with idle to 20.
Notes when acting up (moving only tonight, won't act up sitting still); After holding steady throttle at 3200 rpms, all info within expected ranges (IAC 90, increased timing, slower O2 response but in same range as idle ECT...) Take out of gear and release throttle. IAC jump 10 to 20 steps higher (100 to 110) then falls to 60 to 68 (target and actual) as idle falls to 1280. At this point the IAC adjusts to maintain 1280 rpms, to the point of going wide open (190 steps) if I put the truck back into gear and apply brake to pull the idle down. This carries on for anywhere from 5 to 45 seconds, then it falls smoothly to normal idle.
Just like taking an intermittent problem to a shop, it won't act up when it's suppose to. The idle will normally hang when sitting still in the same fashion as it did moving today.
I'm thinking about setting up the neutral safety on a switch to see if that makes any difference. It is just grounded out since I did the manual swap. I'm not sure why it would make a difference now when it ran fine like that for a few years before the 408, but I'm out of ideas. I also need to switch back to the stock tune (if the it will run on it still) and see if that changes anything since I'm not sure how Hemifever sets up his trans delete tune. Guess I should try Ryan's last tune too since he hasn't done the trans delete. They were all acting the same the last time I tried them.
#24
03-20-2017, 08:06 AM
There are certain advantages to being retired. 
Although, I do got to my part time job today..... Hours there are real intermittent.
I wonder if there is some code in there, that holds the RPM higher, while the truck is moving, with a manual trans..... The tune without the trans delete doing the same thing though.... kinda indicates it is something with one of the sensors.... And they all seem to be doing what they are supposed to. That's just strange....
Although, I do got to my part time job today..... Hours there are real intermittent.I wonder if there is some code in there, that holds the RPM higher, while the truck is moving, with a manual trans..... The tune without the trans delete doing the same thing though.... kinda indicates it is something with one of the sensors.... And they all seem to be doing what they are supposed to. That's just strange....
#25
03-20-2017, 10:30 AM
Champion
Just saw your thread here and giving a "you look at this?" kind of comment. lol
Not likely, but heck...
Check the silly gasket at the throttle body?
Brake booster fitting at the booster?
On a manual tranny, what is the sensor input for relationship to idle? I think you're onto something with the N switch. Other than that, it's the readings for speed and load.
Not likely, but heck...
Check the silly gasket at the throttle body?
Brake booster fitting at the booster?
On a manual tranny, what is the sensor input for relationship to idle? I think you're onto something with the N switch. Other than that, it's the readings for speed and load.
#26
03-20-2017, 08:54 PM
Just saw your thread here and giving a "you look at this?" kind of comment. lol
Not likely, but heck...
Check the silly gasket at the throttle body?
Yes, it's good.
Brake booster fitting at the booster?
Yes, it's good. Did you know the booster can hold vacuum for a week or more? I didn't until the other day. Lol
On a manual tranny, what is the sensor input for relationship to idle? I think you're onto something with the N switch. Other than that, it's the readings for speed and load.
Not likely, but heck...
Check the silly gasket at the throttle body?
Yes, it's good.
Brake booster fitting at the booster?
Yes, it's good. Did you know the booster can hold vacuum for a week or more? I didn't until the other day. Lol
On a manual tranny, what is the sensor input for relationship to idle? I think you're onto something with the N switch. Other than that, it's the readings for speed and load.
This also made me think of something... I can't find my notes for when I installed the magic black box for the speedo, but it was fairly recent (in relation to the 408 install, I'm terrible with time). I hadn't had a speed reading between the time of doing the body/ trans swap and adding that box. I wonder if it it was programmed in there the whole time, and I just didn't notice for lack of a speedo.
This still doesn't explain why it's doing it with all of the tunes though. I'll go change tunes after dinner to make certain and report back.
#27
03-20-2017, 11:09 PM
Ok, all other info is close to the same as previously posted for PIDS. Little cooler tonight so temps were slightly lower. The only drastic change was in IAC counts.
Stock tune (360, auto trans, AC) :
Idle; IAC steps (target and actual) 0 to 1
@3200 rpm; 44 to 46
Moving; 90 to 130. Very aggressive about holding 1280 rpms until stopped.
Ryan tune (for wide open logging, not ready for driving yet):
Idle; IAC steps 4
@3200; 60
Moving; 120+- until stopped. Still wants to hold 1280 rpms.
Fever Tune (this is the tune I've been driving on since installing the 408. Trans delete, 91 canned tune for a 360) :
Idle; IAC steps 20
@3200; 90
Rolling; 90 to 110 until stopped... Sometimes :bonk
This tune still wants to hold 1280 rpms, but only for a few seconds sometimes, and until I'm completely stopped at others. It wasn't as aggressive as it has been tonight. I could apply brake when it was trying to hold the rpms up and it would let me come back down to idle.
The only thing these tunes have in common at this point is they all want to hold 1280 rpms when moving. For awhile it was doing it when stopped too, but now it's not.
If breaking the neutral safety circuit doesn't change something then I'll be after Ryan on the tuning side of it. I'm hoping it's not the PCM, but I don't know what else would cause this glitch. I'll try to get to the neutral wire in the next couple of days and see what happens.
Stock tune (360, auto trans, AC) :
Idle; IAC steps (target and actual) 0 to 1
@3200 rpm; 44 to 46
Moving; 90 to 130. Very aggressive about holding 1280 rpms until stopped.
Ryan tune (for wide open logging, not ready for driving yet):
Idle; IAC steps 4
@3200; 60
Moving; 120+- until stopped. Still wants to hold 1280 rpms.
Fever Tune (this is the tune I've been driving on since installing the 408. Trans delete, 91 canned tune for a 360) :
Idle; IAC steps 20
@3200; 90
Rolling; 90 to 110 until stopped... Sometimes :bonk
This tune still wants to hold 1280 rpms, but only for a few seconds sometimes, and until I'm completely stopped at others. It wasn't as aggressive as it has been tonight. I could apply brake when it was trying to hold the rpms up and it would let me come back down to idle.
The only thing these tunes have in common at this point is they all want to hold 1280 rpms when moving. For awhile it was doing it when stopped too, but now it's not.
If breaking the neutral safety circuit doesn't change something then I'll be after Ryan on the tuning side of it. I'm hoping it's not the PCM, but I don't know what else would cause this glitch. I'll try to get to the neutral wire in the next couple of days and see what happens.
#28
04-13-2017, 10:29 AM