Oscillating Idle

[Blown88GT]

Everything I try seems to make it worse or not noticeable.
Slider = 0 is the most stable which leads me to think something else is wrong.

Searched all forums for something similar, found this.
http://www.msextra.com/forums/viewtopic ... g&start=40

Never stalls & off idle is fine.
Don't understand why it drifts around so much.

ADDITIONAL INFO: No oscillation during ASE & WUE.

[krisr]

Looking at your MSQ you have the PID gains set to "Advanced", IIRC that will use the PID values below the slider. Either try going back to Basic so the slider has full control of your PID control or lower your "P" value to about 15 and lower your "I" value to about 50 and see how the idle responds. Don't be scared of using "D" either, I find it helps prevent overshoot while allowing P and I to react quickly.

[ashford]

ford iac is a pita, there are a lot of physical factors that go into them as well.
for the most part they are designed to flow a certain cfm per duty cycle. engine vacuum pulls them closed so the orfice size is smaller vacuum drops orfice opens, since there is less pressure differential it flows about the same.

this works great when the iac is on the engine it was for. if a bigger cam lowers the vacuum at idle i can change the way it reacts a bit, sometimes the iac flows more as vacuum drops which explains engine surging. in the past i have found that a iac from a smaller engine works way better than the stock one. i have used them from ford 3.0l engines and it works better.

but before you change the hardware make a few checks first

1. flyback diode, most obd1 cars had one built into the harness, some newer iacs have them built into the unit ( this also means polarity needs to be correct). without the diode control is harderto maintain and pwm window becomes much smaller

2. the one you have is not sticky and installed the correct direction( i have put them on backwards before)

3. adjust the idle screw so that desired idle rpm results in a 20-30% pwm.

[Blown88GT]

Changes make no difference. AFR is 17-18?
Been trying to figure this out for a long time.
It's acceptable where it is but doesn't seem right.
Sometimes it will be stable for a few minutes, then back to drifting around.
SC bypass valve is open at idle.
MAF is in long straight section of pipe, signal is clean. Huge power with no boost, ridiculous with.

1. Factory harness is intact, diode is there.
2. IAC is the stock one that came with the engine when I bought car new, 28 years ago. Have cleaned it, tested it against others, all the same.
Engine is stock cam, intake.
3. Adjusted where needed to be with IAC disconnected.

When 1st got MS, had Ford Air Adjuster to get it to idle with EEC-IV. Was able to tune idle with MS & no Air Adjuster, so am still ahead of the game.

[nathanhardy]

how is your timing is it flat and backed off from mbt with a increae below idle to help power up the motor as it drops below idle?

[turbo conversion]

Have you achieved a stable idle with Open-loop (warmup)?

If not that is where you need to start, also set rpm under EGO Control 2-3 hundred above idle target.

Also why is your VE table set to 100 in all the cells, I have never seen this?

David

edit: The afr at idle needs to be 14 to 14.7, 17-18 is way to lean for a steady idle.

[krisr]

Have you achieved a stable idle with Open-loop (warmup)?

If not that is where you need to start, also set rpm under EGO Control 2-3 hundred above idle target.

Also why is your VE table set to 100 in all the cells, I have never seen this?

David

edit: The afr at idle needs to be 14 to 14.7, 17-18 is way to lean for a steady idle.

Looks like he's using maf with ve table to trim it.

[Blown88GT]

how is your timing is it flat and backed off from mbt with a increae below idle to help power up the motor as it drops below idle?

Yes.

...
1. Have you achieved a stable idle with Open-loop (warmup)?
2. If not that is where you need to start, also set rpm under EGO Control 2-3 hundred above idle target.
3. Also why is your VE table set to 100 in all the cells, I have never seen this?
4. The afr at idle needs to be 14 to 14.7, 17-18 is way to lean for a steady idle.

1. About 2 years ago.
2. Had it at 1000, now at 800, no difference.
3. 4.4.4.3 VE trim table (MAF)
http://www.msextra.com/doc/pdf/html/tes ... 2-026.html
4. I know; can't figure out why. AFR Table is set for 14.1 at idle load. EGO is calibrated, etc.

Looks like he's using maf with ve table to trim it.

Will attempt to manually trim those above 100 at the lower left corner to achieve 14.7 at idle. Have previously adjusted the MAF transfer curve below 1.0V to 110%.

Found a setting that might be preventing AFR Table from hitting it's mark.
EGO Control---Controller Auth. +/-(%) is set to 0.
The maximum amount of adjustment performed by the closed-loop algorithm.

[turbo conversion]

I think your main problem is the afr being to lean.

Looking at your log it shows the timing is all over the place, you need to looks into that also.

David

[Blown88GT]

...Looking at your log it shows the timing is all over the place...

Closed loop uses timing to maintain target rpm, thus an effect, not a cause.

No oscillation (hunting) during ASE & WUE.

[turbo conversion]

If you enable Open-loop (warmup) with your current tune do you have a stable idle?

If so then it has to be something in your Closed-loop settings.

Have you found why afr is not going to target?

When you get afr at idle where it is supposed to be you will see a big difference.



David

[Blown88GT]

...
1. If you enable Open-loop (warmup) with your current tune do you have a stable idle?
2. If so then it has to be something in your Closed-loop settings.
3. Have you found why afr is not going to target?
4. When you get afr at idle where it is supposed to be you will see a big difference.
...

1. No.
2. N/A
3. No.
4. I know. Changed VE Table lower left cells to 115 now hitting target.

Before changes, cold start shot up to 2000 rpm for about 30sec. Air temp has been pretty low for here.

[turbo conversion]

After looking at your log I would suggest turning off EGO correction at idle.

Also the timing at idle is swinging between 13 to 22 degrees, it will never idle stable doing that.

Just try setting all the idle cells at say 14 deg and Open-loop (warmup) EGO correction off and see what happens.

David

[Blown88GT]

After looking at your log
1. I would suggest turning off EGO correction at idle.
2. Also the timing at idle is swinging between 13 to 22 degrees, it will never idle stable doing that.
3. Just try setting all the idle cells at say 14 deg and Open-loop (warmup) EGO correction off and see what happens...

1. Don't see any TS setting for that. Unless you mean, raise "EGO Control--->Active Above rpm"; currently at 800 was at 1000. EGO Control--->"Active Above MAP", currently at 20kPa, can raise to 40.
2. I see that. Nothing tried so far stops it.
3. They're all at 16, now. Where in TS do you find Open-loop EGO correction? It's in closed-loop now.

[turbo conversion]

Set EGO control rpm to 1500, this will disable EGO control at idle (or below 1500 rpm).

Can you post your current msq file so we can have a look?

Maybe we can find out why the timing is not steady.

David

[ashford]

adaptive idle is a bit agressive. i would try out -1 instead of -3 and 1 instead of 3. in most cases an asymmetrical curve works best would replace -8 with -4.

the other thing that catches my eye is right at rpm peak maf lowers, and at low rpm maf increases, then right after low rpm map increases then right before rpm peaks map drops. this suggest to me the iac isnt working right for the combo or either installed backward

[DonMaximo]

<just curious> Did C&L provide you with the MAF Flow Curve -OR- did you build that ?

As a Ford-TFI guy, I'm curious if you ever tried any other Control Algorithms, such as Speed Density ??

I would presume the MAF is calibrated for the injectors.

The timing issue is an odd one. What is the behavior when you set timing fixed under ignition settings ?
Just wondering if you set timing to fixed if something else may seem more conspicuous. <just a thought>

I'm experiencing my own timing issue where I cannot use the Trigger Wizard as my timing is not steady, but haven't had time to scope it.
I can easily switch between my OEM ECU and MS3-Pro, so I can rule out a mechanical issue. I just need time.

I wish you well

[Blown88GT]

adaptive idle is a bit agressive. i would try out -1 instead of -3 and 1 instead of 3. in most cases an asymmetrical curve works best would replace -8 with -4.

the other thing that catches my eye is right at rpm peak maf lowers, and at low rpm maf increases, then right after low rpm map increases then right before rpm peaks map drops. this suggest to me the iac isnt working right for the combo or either installed backward

Got a cold start log 1st. When in WUE all is stable. 2016-01-21_WUE_on.msl

As it nears transition, rpm dips low until it catches itself. 2016-01-21_WUE_on_to_off.msl

IAC is installed correctly, have cleaned, tested many times. Will remove & inspect again.
UPDATE: Removed. inspected, bench tested; all is normal, full stroke on actuator at 12V, no sticking.

...
Did C&L provide you with the MAF Flow Curve -OR- did you build that ?

As a Ford-TFI guy, I'm curious if you ever tried any other Control Algorithms, such as Speed Density ??

I would presume the MAF is calibrated for the injectors.

The timing issue is an odd one. What is the behavior when you set timing fixed under ignition settings ?
Just wondering if you set timing to fixed if something else may seem more conspicuous. <just a thought>

I'm experiencing my own timing issue where I cannot use the Trigger Wizard as my timing is not steady, but haven't had time to scope it.
I can easily switch between my OEM ECU and MS3-Pro, so I can rule out a mechanical issue. I just need time.
...

Flow curve from C&L. Sample tube matched to my configuration
Started with SD, MAF was much better. Raised flow curve 0-1V by 10%.
Will try fixed timing later.

[turbo conversion]

Try turning off Idle Advance (adaptive) and see what happens.

The -4 to +4 deg. it is set to is the timing swing showing up in your logs.

David

[Blown88GT]

Set EGO control rpm to 1500, this will disable EGO control at idle (or below 1500 rpm).

Can you post your current msq file so we can have a look?
..

It's steadier, but rpm dips to 573 (min), 859 (max).
Datalog of this 2016-01-21_EGO_1500rpm.msl