Injector Tip Temp

[DontCallMeSurley]

Heads up I'm a complete newbie at tuning. I have a GTO that I am playing with the tune. I had it dyno tuned after headers were installed and it's been running well for a couple years. I wanted to learn to tune before I put in a new cam so if I screwed it up I could reflash the old tune. So I am currently working on calibrating the MAF. I have it in open loop, DFCO off, it's forced into only MAF, etc. I reflashed on a cold engine and then went for a 30 minute drive to do some data logging and everything went smooth. I then pulled into a parking spot and let it idle while I reviewed my logs. Over about 15-20 minutes of idling my Injector Tip Temp began climbing from 149 to 180+ and at the same time my car began to run richer and richer at idle all the way to 0.8 lambda. This seems to correspond with the offset injector temp table. I've read several of the threads pertaining to injector tip temp but from my understanding a lot of the issues were when reflashing on a hot engine where the ECM grabs ECT to populate tip temp which causes a rich after flash. This was not my issue as I flashed a cold engine and it was not running rich until 40 minutes later when I parked and let it idle. I have stock injectors so I'm assuming this I would not need to recalibrate the offset vs injector tip temp.

My question is, how is my ecm calculating injector tip temp. After the reflash did it lose data where now it is calculating the tip temp inaccurately? Also, could this have always been the case but my STFTs were correcting the rich condition at idle. I just installed the wideband so I do not know if my car kept running richer and richer at idle on the original tune from the shop. My ECT and IAT were all fairly normal and nothing else was running hot. For what it's worth I live in S. Florida and it was 90+ out. Once I started driving again my ITT started coming back down and my car started to run closer to stoic again.

[smokeshow]

It is a model. Inputs are airflow, IAT, ECT, EGR, and a couple other things. If its stock injectors, best leave it alone.

[blindsquirrel]

I have it in open loop, DFCO off,

Why? Is it a race car, like the kind that gets trailered somewhere, the tune adjusted to that day's specific weather conditions, then run and put back on the trailer to go home?

[DontCallMeSurley]

It is a model. Inputs are airflow, IAT, ECT, EGR, and a couple other things. If its stock injectors, best leave it alone.

So should I be concerned about it running so rich at idle?
Once I enable fuel trims will it continue to idle so rich or will the STFTs try and bring it back to stoic?

[DontCallMeSurley]

Why? Is it a race car, like the kind that gets trailered somewhere, the tune adjusted to that day's specific weather conditions, then run and put back on the trailer to go home?

It's only disabled when logging EQ ER ratio for MAF tuning.

[blindsquirrel]

It's only disabled when logging EQ ER ratio for MAF tuning.

That is... suboptimal. Yes, I know that's the way all the youtoob celebs tell you to do it. They are wrong.

[smokeshow]

That is... suboptimal. Yes, I know that's the way all the youtoob celebs tell you to do it. They are wrong.

Comment of the year.

[DontCallMeSurley]

That is... suboptimal. Yes, I know that's the way all the youtoob celebs tell you to do it. They are wrong.

I was following the SD tuning stickie on the READ ME section of the forums too that lead you down that path.
What would me a more optimal way to do the MAF tuning then which might be a loaded question I'm sure. Is there a better right up in the threads?

[smokeshow]

I was following the SD tuning stickie on the READ ME section of the forums too that lead you down that path.
What would me a more optimal way to do the MAF tuning then which might be a loaded question I'm sure. Is there a better right up in the threads?

Yes, don't invite additional variables by taking MAF data while heat soaking during an idle for 20 minutes.

[blindsquirrel]

Use fuel trims to tune the closed loop regions, using data from the actual narrowbands that will be controlling it after you are 'done' (whatever 'done' means, to us weirdos who never stop tinkering with things).

And since you're tuning it based on what the NBs say, replace them before you start. If you have any unknowns about the upstream sensors that are in it, like their age, condition, brand, etc., just replace them. Start fresh. GM/Delco, NTK, or Denso only.

Use filters to exclude any data you don't want - like exclude everything that's open loop/PE, or when DFCO is active, or when it's in particular Fuel Trim Cells where it's doing things you don't want data from...

[DontCallMeSurley]

Yes, don't invite additional variables by taking MAF data while heat soaking during an idle for 20 minutes.

I wasn't collecting any data logs while idling. I had my scanner hooked up but had already saved my log from driving around earlier. Nothing from that time idling was used to make any adjustments. I think I understand how the temps rising were causing some of the multipliers to drive the A/F ratio down. I guess my question is, is this normal for such a rich condition from getting heat soaked at idle or did it only continue to get so rich because it was only on the MAF and fuel trims were disabled not allowing it to try and come back to stoich. If everything was enabled like normal, closed loop etc, would it corrected itself from getting so rich?

[DontCallMeSurley]

Use fuel trims to tune the closed loop regions, using data from the actual narrowbands that will be controlling it after you are 'done' (whatever 'done' means, to us weirdos who never stop tinkering with things).

And since you're tuning it based on what the NBs say, replace them before you start. If you have any unknowns about the upstream sensors that are in it, like their age, condition, brand, etc., just replace them. Start fresh. GM/Delco, NTK, or Denso only.

Use filters to exclude any data you don't want - like exclude everything that's open loop/PE, or when DFCO is active, or when it's in particular Fuel Trim Cells where it's doing things you don't want data from...

This does make sense to my little peanut brain. I appreciate the help, like I said I am extremely new to this so I appreciate you taking the time. So tuning off Fuel Trims for closed loop regions would be preferable then EQ Error from a wideband. And then the wideband would become a more useful tool for open loop areas, PE etc?

[blindsquirrel]

You can log/graph both fuel trims and wideband at the same time (in separate graphs, of course), without disabling anything in the tune, and use filters to clean up unwanted stuff. Only graph trims data when EQ = 1 and throttle is > 0 and whatever else, and only chart wideband stuff when OL/PE = yes, or EQ > 1.

Filters and the PIDs they map to are kinda vehicle-specific, it's about impossible to have a list of filters you can just copy/paste and go with. You pretty much have to build them as needed.

[DontCallMeSurley]

You can log/graph both fuel trims and wideband at the same time (in separate graphs, of course), without disabling anything in the tune, and use filters to clean up unwanted stuff. Only graph trims data when EQ = 1 and throttle is > 0 and whatever else, and only chart wideband stuff when OL/PE = yes, or EQ > 1.

Filters and the PIDs they map to are kinda vehicle-specific, it's about impossible to have a list of filters you can just copy/paste and go with. You pretty much have to build them as needed.

This makes a lot of sense. Was disabling multiple things within the tune to not influence the data collected just an old way of doing it that the filtering function has now made it obsolete? Once again I appreciate the help. Half of the learning curve seems to be filtering out good from bad techniques and advice. The internet (YouTube specifically) is a blessing and a curse.

[smokeshow]

This makes a lot of sense. Was disabling multiple things within the tune to not influence the data collected just an old way of doing it that the filtering function has now made it obsolete? Once again I appreciate the help. Half of the learning curve seems to be filtering out good from bad techniques and advice. The internet (YouTube specifically) is a blessing and a curse.

Probably just due to improvements in the scanner over time. The ECM itself utilizes clever filtering to extract signals from the noise...so it makes sense to use that as far as it will take you.