Not knowing exactly how TT set you up - but assuming they have a operational base flash in your UTEC - the solution is easy - just unplug the utec and run directly into the ecu to run your flash till they can return. It should run perfect on just the flash.

 

Given your hyoptechical - the Utech would be "reading" the ecu map off the factory code in the stock ecu. Seems very doubtful.

 

I don't think its reading the ECU's code, but it may be reading the desired injector duty on its "ECU Side" of the harness, interpolating it, and sending it back out with what it sees as a correction.

Since the UTEC has a OLF (Open loop fueling) Crossover point, if its below that point I think it still offsets the MAF signal which means I have to assume it shouldn't matter... With that said, the UTEC is aware of when the ECU drops out of closed loop fueling into open loop (I can see it in the digital logging and on its built-in dashboard) which means if the car swings into open loop at idle, it might just take over.

Ok.. after all that ramble, I agree with you, and also knowing how flashes and the UTEC works, I don't see any reasonable explanation for why the flash would be troublesome at all, in fact I don't see how it would have any affect other than the "Transition hiccup" which is really just altering the low load cells for the fuel and timing to match the flashed ECU's different values more closely.

What I was saying earlier about the injector scaling seems reasonable (adjusting an already adjusted value) However it doesnt make sense that it would cause any trouble anyway, plus after discussing it with him, he didn't have those injectors at the time of the reflash so it didn't apply anyway. I think at this point there's some level of adjustment to the injector size, and idle fuel/timing to help things...

I just think the UTEC's OLF features is new ground, and nobody's seen all the glitches yet with different combinations of hardware including reflashed ECU's I know I wouldn't have come across this at all, and likely none of the other beta testers wouldn't have because the others, like myself, likely weren't testing with an already reflashed ECU.

 

In Bog Al's defense. I already discussed my problems with him and he offered the options discussed above. I just wanted to find out if anybodu else was having issues with flash/Utec.
I suspect my problems are elsewhere. I'm starting with injectors, (I've suspected a bad #2 for a while), then on to vac leaks, (I've already found 3 boost leaks and fixed them). I also have a VERY noisy valvetrain which could be affecting the knock sensor, (I consistantly get high knock countsaround 3500rpms).
I also started getting that P0300 and P0171 codes. Maybe a bad stock O2 sensor? Al said others have got the P0300 code after installing dual plate clutches (harmonics/knock).
So I have alot to check out before I start dumping my Dynoflash (which has been great).

 

I am going to wait for Jermaine at TXS to get back and take a look at some of my runs that VTECH8TR helped me with. Hey Malibu, Still intereted on your thoughts to. I am holding off going back to the stock injectors until I can see if we can hammer this out or I will stick with the flash for now.

 

Yeah I think its going to end up being a matter of adjusting your injector size slightly in the UTEC config..

 

Whatever we try to do will be fine with me. I will have to base my AFR on the EGT for now if we change the injector values since I dont have the tuner.

 

I may have an idea on what is causing this problem.

I will need to know the following info to determine if my diangosis is accurate

HOW DOES the UTEC reference between closed loop and open loop operation of the ecu

is it TPS based, load based - or based on some other refernce - if so what is it ?

Is the transition area adjustable ?

Thanks

 

Yes, there is a crossover point (By default set at 35% and it can be adjusted) and its referred by TPS, this is generally how it works.

Also, the UTEC also can tell if the car is in open loop when at idle and when its cold and not yet closed loop. The ECU apparently has an output that signals whether or not its in open loop or closed loop operation, not sure what signal it is, but when my MAF sensor was malfunctioning, I saw it swing between open loop and closed loop at idle in the UTEC built-in dash.

 

There's definitely no signal coming out of the stock ECU that indicates whether it's running in open or closed loop mode. One really hokey way would be to look at the front O2 voltage - if it's cycling between high and low voltages, then the stock ECU is in closed loop mode. Can you explain why the UTEC would care what the stock ECU is doing?

Tom

 

I sent a PM to you Malibu. I have the stalling stabilized. I had to take out the 36 degrees of timing out of the 0% column for the rpms between 500-1000. I guess the ECU became erratic trying to compensate between the ECU timing and jump in UTEC timing. I had to start over on the fuel side but that helped with the ideling a bit to. I understand why the timing was advanced so the motor could get a smoother idel, but I am fine with the lope as long as it doent stall.

 

Specifically if the UTEC is aware of open loop and closed loop operation, it can allow injector scaling to work in the 0% column when closed loop operation is not functioning since injector scaling is only useful in open loop operation, fuel trims and O2 sensor readings are what allow closed loop to do its job.

And I know for certain that there is some indicator of openloop operation because the UTEC does indicate it when it switches in and out when the TPS is below the crossover threshold... I just don't know what that signal is, but its probably some output signal that energizes a solenoid or relay that is only active in open loop operation (or closed loop)

 

I don't see the relationship here. The stock ECU wants the O2 sensor readings to switch between slightly rich and slightly lean (and thus, high and low voltage) when the engine isn't under heavy load in order to get an average of exactly stoich. To do this, it gooses up the injector pulse width a bit to make the engine run rich, and then gooses it down a bit to make it run lean. When you see the O2 voltage changing, that's the ECU alternately goosing the pulse width in "closed loop" mode - closed loop meaning that the stock ECU is looking at the O2 sensor as it does its goosing.

From the factory, the stock ECU expects some baseline injector pulse width around which it'll goose. As an example, let's say that's 2 ms at idle. The fuel trims adapt for clogged injectors and the like by changing that 2 ms to, say, 2.5 ms. Then at idle, the pulse width will be set to 2.5 ms, +/- some goosing.

If you plug in larger injectors, the stock ECU will try to compensate for them by changing the fuel trims. When it runs out of adjustment room on the fuel trims, the stock ECU will always run in open loop mode, since it won't be able to goose the injector pulse width down enough to get the motor to run slightly lean. To fix this,
you need to do one of two things: 1. drop the MAS frequency (to the stock ECU) down to compensate for the larger injectors, or 2. ignore the stock ECU's injector pulse width and output a different pulse width to the injectors directly.

I maintain that "injector scaling" is useful in both open and closed loop operation of the stock ECU, but for different reasons.

Seems like we're solidly in disagreement here - I'm confident that there is no signal, and that the UTEC can only infer that indirectly from the front O2 voltage. You could semi-prove this if you had a log of this behaviour, and the change of modes trailed when the O2 voltage went solid by a half or 1 second.

Tom

 

I concur 100%

My position is that the "issues" with the flash can be attributed to the need for fine tuning with the UTEC.

Getting something to idle like stock with a quasi stand alone such as utec may take some time when dealing with larger injectors and other mods such as cams

It seems the UTEC has taken the leap to full injector and fueling control and as such it may require additional tweaking to smooth out the idle

I have not had a chance to play with the new updated UTEC softwear version which has injector drivers so I don't have any suggestions about what to adjust to improve the idle

 

We'll have to wait for someone from TurboXS to chime in to clarify this.. I'm not certain if you've mentioned if you had a UTEC or not, but when you run the dashboard, it very clearly indicates whether its running in open or closed loop, there is a log level that does record some alternate digital signals and some bit signals (on or off) I honestly can't tell you if they indicate open/closed loop in that log simply because I don't recall. There's definitely an indicator of whether or not its running open loop or closed, how it determines that is irrelevant, but how the UTEC acts when its aware of each state is what we're trying to figure out right? (Regardless of whether there's a real signal or not we do know its something calculated or indicated by the ECU since a scan tool does indicate it, and the UTEC is certainly aware of its state)

I do agree with most of what you said about how the closed loop fuel operates, and when your dealing with very large injectors, it makes perfect sense since you run out of adjustment in the trims.. Thats not really the debate here.

However what I am trying to establish (and figure out to some extent) is if the open loop functionality (the UTEC OLF feature) ceases to function below the crossover point, and if below that it alters MAF value only, or if it intercepts the signal from the ECU and scales the injector signal accordingly regardless, or it only acts when in open loop and directly controls the injectors from a background map.. (I tend to think that its operating on MAF frequency below the crossover threshold)

This is obviously a technical detail that none of us has any real info on so we'll have to wait and see.

With all of that said, I have to agree that it really seems to be mostly a "Tweaking" issue and for the most part, is just a learning curve since the background "Map" in the OLF feature is designed around a stock ECU, therefore if a reflash makes alterations that alter the duty cycles, then the background map would be out of sync and cause a jump on transition (Therefore a hiccup) At that point its really just a bit of tweaking.