Wandering Idle mixtures and FIDLE issues

[daniel505gti]

I have 2 issues that I am trying to figure out. The car is running well with 2 exceptions.

1. wandering mixtures at idle. I have all corrections turned off and I am trying to get the base ve right, I have a wide band o2 (Techedge).
I have the Injector opening times drilled down to 0.8 and ms/v adjust to .10 and injection delay set to 30 degrees (best idle characteristics)
My engine is a 4cyl Turbo firing order 1/3/4/2 running 37 lb Siemens 9267 injectors 15 ohm (pwm disabled). Running 2 squirts alternating.

I was told that the batching of injectors should be following the crank for best results (i.e 1,4 and 2,3 together) I would have thought that following the firing order would be best as those 2 valves open close to each other. Could this wiring cause any weird issues? I assume due to the 2 squirts that all cylinders would get fuel and since the ECU does not know when cyl 1 event is it is random as to where / when injection events occur (which stroke / ignition is the first event) so the paring would have little effect so long as you cover the basic requirement of events needed to cover all ports for 720 degrees.

2. I wired up a LPG solenoid as a fast idle valve (Spare I had around) and now it always stays ON. I read later that the fiddle control is only rated to run a relay not a solenoid and also should have a diode for flyback. Having overloaded the fiddle circuit is the failure of that circuit likely to stay always grounded? (I have mega tune set to solenoid and 60c / 140f )

Cheers Guys in advance.

[devastator]

Is your WBO2 giving you the idle issues you refer to, or is the VE table "hunting" between values? For what it's worth, I switched to Simultaneous injection and my idle smoothed out immediately. I tried several pairing combinations, (my firing order is 1-4-3-2), and finally gave up on alternating.

[daniel505gti]

I have the ve table set up so the values are stable around idle, the duration and pulse widths are the same in both 15.5 to 13.5 swings in mixtures. The car runs differently suggesting the o2 readings are correct. And under load the readings are always the same.
I have tried varying injector batching my self. I can only really conclude that maybe the fuel reg is not quite healthy or maybe a bubble is getting stuck changing the mixtures. I will be fitting a one way valve soon.

Thanks for the thoughts, Daniel.

[drholl]

I have a TBI setup,350 Chevy. I have not yet solved my rolling idle yet but tomorrow Ill try again. Like you I set up all the VEs, AFRs and spark around idle to remove variables from the idle settings. That's probably the way to go. Please let us know how to solve an unsteady idle if you find out. I will if I solve it.

Mine rolls from 700 to 1100 RPM and it is very rich, 12:1 AFR.

Previously I tried to lean it out a bit, but that didn't work at that time.
Holl

[devastator]

Is your idle moving from 1 VE bin to another during idle? Is it moving from 1 Ignition Advance bin to another during idle, (if MS controls your advance)?

[daniel505gti]

I have set up the tables so the load points encapsulate the idle area.
I,e. 800 rpm and 1100 rpm points, and 20 and 50 kPa. Map at idle is pretty stable around 45 kPa and advance is steady. Pulse widths are fairly stable to. The problem I have Is best described this way. Say you tuned for 14.7 @ idle but did so during warm up. After a drive idle is now lean. I never tune until warm up is off. Also I can stop the engine and start in 30 secs and after ase enrichment has finished it can also be leaner. I have not set any x-tau settings. As for idle mixtures I have tried both 13.5 @ 8 degrees advance and 14.7 @ 10 degrees advance and similar behaviour happens,

Cheers.

[devastator]

Change your VE table so the idle, after warmup, is at the AFR you want.

[daniel505gti]

Yes it is. Above was an example.

[66fb]

daniel505gti,

My engine is doing this same thing -going lean in idle bins after reaching operating temp (around 200*F). I have those bins set so they can only be manually tuned.

A log shows gammaE in the low 90s (%) at this time which means some factor is pulling fuel. To stop this "enleanment" until I can figure it out I'm using the "Non linear IAT fuel correction" table (I'm using GM sensors) and giving it +10% at 200*. I've reviewed all the MS setting several times and so far can't see what I'm missing.

My IAT sensor is located in a 3" steel pipe between the throttle body and the air filter -it's temp seldom gets to 150*.

[drholl]

Check your AFR, only after the engine is fully warmed up.

And, if you can not find out what is causing it, heres what I did, mine is fixed. (It was the engine code changing).

I set all my bins similar to these "basic tables" VE, AFR and Spark; and datalogged, then went through each setting in the log until I found something that happened at the same time as the anomaly. Mine was accel enrich caused by TPSDot threshold being too low. Thanks to Lance and devastator.

This is for testing only, don't drive it...... many of the other values are probably wrong. Nuts, some I haven't even looked at in awhile becausae I knew this was only an idle test.

26 154 12 Spark no drive chg PWM 10-25.msq

"Look at the basic tables". This eliminates many variables. Set the values to what you need to start and idle your engine.

Let the forum know what your outcome was. This will help others.

P.S. do you have any good values to put in the acceleration wizard?
I'm trying to get mine dialed in tomorrow.

Have fun with the test.

[daniel505gti]

Sorry for the no reply, I have just returned from a long drive to and back home from my brothers wedding, My issues changed priority from this weird mixture issue to miss firing. Input was sorted after purchasing a cro however the misfires persist but at least I know the signal to processor is clean almost feels like 1 cylinder is rev limiting and triggered by map moving in to boost to quickly :S. I have ran out of time and my patience is also not right for debugging as I am snowed down with return from holiday work. So I persist driving with the issue. I have seen 2 code revisions in the last month but unsure exactly what the fixes are per revision as the revisions page only separates on major revisions not minor. Some day soon I will get the patience to try again or I will bite the bullet and get an autronic setup, It’s not my peered direction as they are costly but I know a few people that have extensive experience with there ecu’s and they can do the advanced features I would benefit from.

My issue with wandering mixtures was not a warm up issue. But might be heat soak in to the inlet air and map dot. That has given me something to look at, I will have a look some time son at the msq you have posted.
I can't get a grip on the acceleration wizard, Unfortunately my brain works backwards to what most of the documentation try's to tell me. It's the sort of thing that 2 min with an experienced person would have everything understood. Also because the values do not relate to others i can't corolate to easily. If anyone knows of any vids explaining how basic acceleration is tuned that would be helpful? maybe someone has a few min and a YouTube account ;)

Cheers guys, thanks for all the pointers and advice.

Dan.

[devastator]

Input was sorted after purchasing a cro however the misfires persist but at least I know the signal to processor is clean almost feels like 1 cylinder is rev limiting and triggered by map moving in to boost to quickly :S.

I hate to be picky but could you clarify this please? What is a cro? When it the misfire happening, (under boost, all the time, when accelerating, etc.)?

I have seen 2 code revisions in the last month but unsure exactly what the fixes are per revision as the revisions page only separates on major revisions not minor.

I think you can get a good tune with the code version you have so I would not recommend updating as it could open a whole new set of issues for you.

My issue with wandering mixtures was not a warm up issue. But might be heat soak in to the inlet air and map dot.

Look for the ACCEL light to blink on in your datalog, without your moving the pedal, (TPS reading). If this is happening it is likely the MAPdot or TPSdot triggering the Accel on it's own.

I can't get a grip on the acceleration wizard, Unfortunately my brain works backwards to what most of the documentation try's to tell me.

Accel wizard is tricky and hard to diagnose without being in the driver's seat. I run 100% TPS as I discovered that my turbo would trigger the ACCEL with MAP accel active. Try setting the top 3 accel/% to 100% and just tune the lowest one as you tap the pedal lightly enough to trigger. After you have this one set, max it out at 100% and move up to the next higher accel/% "box" and repeat the previous throttle action, only a little faster, until this works well. Continue this procedure as until you have all 4 "boxes" set to where you want them, and return the % values that worked for you in each.
I've also found the ACCEL wizard in MS Tuner Studio to be helpful in that you can "grab" the graph and drag it back and forth, (for pedal speed), and up and down, ( for "squirt" amount). This removes the need to enter numbers manually.

[daniel505gti]

Hi devastator thanks for the reply, I will check again the accel for map, the turbo does boost very quickly. There is virtually no lag and seems to be rapid boost related. The cro I got is a usb one for a pc, 40mhz dual trace, and was only 450 aussie dollars, cro is the generic name for it since all were based on cathode ray tubes. I should have said usb oscilloscope, sorry for that, old habits. I am using code version 2.886 with no x-tau and most other fine tuning options disabled. I will check map accel and update firmware soon. If the issue still persists I will make a log of it and also post a msq.
Update, I checked and accel is 100% TPS.

Cheers again, Dan.

[devastator]

Try setting the top 3 accel/% to 100% and just tune the lowest one as you tap the pedal lightly enough to trigger. After you have this one set, max it out at 100% and move up to the next higher accel/% "box" and repeat the previous throttle action, only a little faster, until this works well. Continue this procedure as until you have all 4 "boxes" set to where you want them, and return the % values that worked for you in each.

Did you try this procedure?

[daniel505gti]

Sorry for the delay, I have been rolling out a hyper-v conversion of servers at work and have been concentrating on that migration.
I have today updated to 2.888a firmware and have taken a data log. I have not tried the accel changes as the default setting go past 100% on the first box to 1540 in the last and I was looking for more info. From you last post I assumed that setting to 100% was effectively removing that bin from being effective However I am confused as to why larger % would enrich. I know default mega squirt settings are literally just place holder settings for most compatibility and also for the stimulator to work well for building.

Attached is my msq and log file. I tried to surround the misfires with a manual mark however there is a few seconds delay as I was driving and also in the steady cruse state there is a random miss, not related to my main massive misfire during acceleration / boost. I have tried to remove most other factors from the equation such as x-tau and iac corrections.

Any ideas will be greatly appreciated. This one has me beat and exhausted, even tho i expect it to be a stupid mistake on my behalf.
FYI My triggers are 2, 5mm slits in the flywheel 180 degrees apart.
Cheers.

[devastator]

I have not tried the accel changes as the default setting go past 100% on the first box to 1540 in the last and I was looking for more info.

I don't understand where you are putting 1540.

From you last post I assumed that setting to 100% was effectively removing that bin from being effective However I am confused as to why larger % would enrich.

The settings are based on how fast you press the pedal. I forget that my fastest accel value is 100%, while most are much more than that. Sorry. Try setting the PW increase to 0 in each bin, (instead of maxing out at 100%), in order to tune each individually. I think you are understanding me better than I am explaining myself.

[drholl]

I think that the 1540 is from a screenprint from an older web-page. I think that was from when the values were off because of a misplaced decimal point in the coding (I'm not sure). But I'm pretty sure, what we now use would equate to a 154.0 but we leave the ".0" off. And I think that would be equal to 154% of the TPS reading in 1 second, not 154% fuel. the 1540 could probably be met by just tromping on the "go" pedal, like a brick falling off a building when it hits the ground. That 1540 had me a little confused at first also, so don't feel like you were alone in your confusion. See if the screen print is what you were basing your 1540 on. If so I used the second one.
154 is about equivalent to going from an idle to WOT (wide open throttle) in about 0.7 seconds and an increase of 3ms in pulse length. Pretty easy to do.

The Analog to Digital signal used In the old days was in "Volts per second", and it was a 0 (IDLE) to 5 (WOT) Volt signal. But percent is more easily understood so they went to %/sec. From idle to WOT is about a 0 to 5 Volt signal, and about 5 V/sec = ~100%, therefore 100% per second would be equal to flooring it in about 1 second.

I'm not experienced with EDIS or anything like that, Heck, I still use points to control my MS II, which does the advance.

And I don't do boost. But check with others about boost, as I think your VE tables should go all the way up to the boost ranges, maybe 200 or better. Yours only go to 100KPa, but you reached 150KPa. In MegaTune use Tools/review mode and it's in there somewhere.

Your Accel enrichment is almost never coming on, check that part out. If your TPS and MAP dot thresholds jump around too much you can mellow them out with the lagging factors (under "Fuel setup/general"), set them to ~50, That worked for me.

I'll look at the DL and MSQ in detail tonight.

I hope this helps.
Holl

[daniel505gti]

I tend to confuse my self faster than understand lol.
Attached is the default settings for the accell wizzard. I will try changing the value (ms) to zero and see what happens.

Edit # I changed the values to zero and also map dot threshold to 200 and it's a lot better, However it still will misfire at idle and occasionally on accell, however values of zero were much better, the defaults are to aggressive for 4cyl engines I imagine.

[drholl]

My mistake, I was looking at "MY" VE kPa not yours. Oops. I forgot to change the msq to yours.

I'm just not the person to know what's going on with a "booster". Maybe someone who boosts can help.

Sorry
Holl

[daniel505gti]

Drholl, Thanks, we posted the same time ,

The explanation of accell values makes sense now, 1540 was a pretty high % and is what was throwing me, the change to % opening I thought was a good move.
I think the random misfires are ignition related as when I run the dizzy to control advance everything is fine, I pretty much need to set up the trigger settings similar to a VR dissy pulse, My trigger produces a very short pulse. I can see with a timing light that the advance jumps around a bit to, especially at idle.

I do rarely hit accell, and this is because of boost, it just pulls away with very little throttle and when it's going you just don't need to push the peddle hard. It's very weird, I can't see the misfire in the logs, but it's chronic, even durations during the miss and o2's don't change that much. It feels like rev limiting and the weird thing is when i do rev high there is none. so I tried turning it off and no change. It has me scratching my head a lot.
I will try to get a better log for analysis, It will take me a little while to do as I am busy again.

Thanks guys all good pointers to check.