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ECMlink Lean AfrEst high CombinedFt

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TupperWare

Probationary Member
26
3
May 6, 2020
Portland, Oregon
Alright I'm pulling my hair out currently.

I'm having an issue where my AfrEst is SUPER lean throughout the whole rev range even driving and throwing off my CombinedFt. The car was bone stock, put V3 on it stock and was fine, I then put a set of Crower stage 2 cams in since I had them laying around and did a full 3" straight pipe. Stock injectors and MAF, car was great.

I then put the car on speed density, HKS BOV, and PTE 880cc injectors. I have the injectors scaled as too what I've found in other forums that work for others. I have stock pump and FPR. This is now where I'm running into this issue.

I can get the combined and AfrEst in the right ball park with adjusting deadtime but it runs poorly and still when revving or driving it wants to be much leaner. You can see in the log of how it wants to be, then in boost it was super lean until I scaled the global a bunch to be around 1000cc injectors but I know that will just be bigger problems an that just doesn't make sense to what the injectors actually are.

I haven't checked for any boost leaks yet but I don't see it being one as it was fine when I was still MAF and I still have all stock piping and side mount besides the piping from where the stock BOV would be to the throttle body has changed.

This is an idle log and a slow rev. I've messed with V3 for a bit now and tuned a couple cars especially on speed density and this is the first time I've ever experienced something like this.
 

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If you're scaled to "1000cc" injectors, they will fire less often, IE you will run leaner. I haven't opened your log or settings etc, which I could do later tonight, but that comment already gives me a red flag. Honestly, who cares if the "global" value doesn't match the injector or what "most" others have used for their tunes? the injectors could be old and tired....you may have a poor batch, etc. If your car is running properly, no boost leaks, timed correctly, etc. get the WOT and global values calibrated so that your existing AFRs match. THEN....get your deadtimes in check.
 
I have done all of that, the injectors are currently scaled as to what I’ve read 880s actually flow and that 790cc. With the current settings the car runs better than it ever has even with stock injectors. I’ve only scaled them to 1000cc once to get the wot afr closer to target but again, to have them scaled that far off of what the injectors are isn’t right. When they were scaled as 790 they were super lean in WOT, and when I scaled them to 1000cc it got richer in WOT which is backwards have set it back to 790cc, check the log. I have dead times set to 420 which is specifically said on ECMLink wiki for these injectors as well.
 
Speed density isn't affected by boost leaks but an exhaust leak will potentially throw off O2 and that will cause an issue. Most culprits I've seen are at the O2-downpipe gasket.
Where did you get the values for the InjBatteryAdj DA table? They're fairly different than stock, which could be fine for those injectors, but they're used in addition to deadtime in global fuel. That will affect idle and cruise more than WOT but we don't have a (near-)WOT log.

Scaling the injectors back to be seen as larger than they are but doing so causes it to run richer.. I don't have an explanation for. Can you throw up a log of that?
 
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If you're talking about pressure loss between two vessels (intake manifold and the cylinders) whilst connected via an intermediary volume (intake tract cross-section taken right at the valve seats), I think I know where you're going. However, intake manifold and the intake ports are considered the same vessel, including all gasket/seal interfaces in the IM. The intake manifold would only be unable to build target pressure due to a leak occuring as it is within the same vessel as the sensor, making the turbo work harder for the same power, but the sensor would not be reading additional volume (ideal gas law) as the vessel is not perfectly sealed. Your VE remains unaffected as the pressure and temperature measured in the intake is absolute with all the leaks occurring. It's just not ideal because you're unable to build that pressure as fast due to a leak. Like trying to pump up a tire with a tiny hole in it -- the pressure in the tire is the pressure in the tire (and volume can be calculated from IGL), but it just takes more work to do it.
Admittedly, with a large enough leak in the "sensored volume" in vacuum, that could cause a problem. You are no longer able to measure true cylinder vacuum as you approach infinite volume, the atmosphere. So your idle and cruise could be thrown off by a large enough leak, I will concede. I would think it would have to be pretty large to cause a noticeable vacuum loss, though, and when in boost it would become probably quite audible.

If you have an alternative perspective, please share it -- it's an interesting topic (not sarcasm :) )
 
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A vacuum leak around the injector seals in this situation would help as it would draw in unmetered air.

You are PIG RICH. The ECU is pulling 29% fuel just to get the desired wideband reading. You need to ignore the number scribed on the injectors and whatever you read other people doing and make some serious adjustment to your global fuel.
 
A vacuum leak around the injector seals in this situation would help as it would draw in unmetered air.

You are PIG RICH. The ECU is pulling 29% fuel just to get the desired wideband reading. You need to ignore the number scribed on the injectors and whatever you read other people doing and make some serious adjustment to your global fuel.
So then the injector seals allow enough air to significantly alter AFR but not enough to alter measured vacuum, since the injector seals and the manifold/map sensor share the same vessel (ie. The interior of the manifold and all the intake runners are the same pressure vessel)

I would have thought, if anything, an IM system leak anywhere post TB would drop measurable vacuum because it's now sharing itself with the atmosphere, which wouldn't be indicative of what the cylinders are actually trying to produce. Hence, less vacuum seen outside the combustion chambers which causes the ECU to increase fuel (depends on stated VE of new cell) inappropriately causing a rich condition.

I mean, you can't really have the same vacuum reading in a two identically sized vessels, one having more air in the system than the other, can you? Although with a leaking one, it's interior volume is actually perceived as larger since its sharing it with atmosphere..

Oh dear I think I've gone cross-eyed.
 
Yeah, it's quite a bit. Global deadtime plus DA table ain't helping.
What's wrong with the DA tables?

Ultimately the only way to know if the fuel system is calibrated correctly is to see it at WOT during peak VE using arguably the most accurate sensor in the car paired with the computer we all love controlling everything. I suppose, based on his log, it could be correct and the next move would be a wildly ridiculous deadtime adjustment. But looking at it after looking at datalogs daily for 15 years I'm gonna place my chips on that not being the situation. His 880s seem to be flowing 29% more - which is fine. They're only numbers. The entire game is getting the physical parts to jive with the ECU. Nothing else matters.

If I was OP, I would aggressively adjust global fuel. If more adjustments were needed beyond that to make it all work [deadtime, tip-in, etc] which also seemed rather aggressive, I'd probably jump ship on the injectors. I don't think that'll happen though, I think they just flow way more than scribed on the side of them for reasons unknown and I don't see it as a bad thing in any way.
 
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What's wrong with the DA tables?

Ultimately the only way to know if the fuel system is calibrated correctly is to see it at WOT during peak VE using arguably the most accurate sensor in the car paired with the computer we all love controlling everything. I suppose, based on his log, it could be correct and the next move would be a wildly ridiculous deadtime adjustment. But looking at it after looking at datalogs daily for 15 years I'm gonna place my chips on that not being the situation. His 880s seem to be flowing 29% more - which is fine. They're only numbers. The entire game is getting the physical parts to jive with the ECU. Nothing else matters.

If I was OP, I would aggressively adjust global fuel. If more adjustments were needed beyond that to make it all work [deadtime, tip-in, etc] that also seemed rather aggressive, I'd probably jump ship on the injectors.

Maybe nothing, maybe something -- I'm not sure if 520usec total at 14V was intentional. Seems excessive from what I've read about the PTE 880s but I know every set is different. Some more wild than others.

It's interesting how at 7V it's actually less than stock and by a sizeable difference given how 9V jumps above stock by nearly 200usec. That was kind of surprising, but maybe they work really well at low voltage. I've never dealt with PTE so it's just a first for seeing that for me. You undoubtedly have more experience and knowledge which I'd like to soak up like a sponge.
 
Without even looking at the log you mentioned this happened after the 880 install. I'm assuming you bought these used either on here or facebook. Buying used injectors is always hit or miss especially since not everyone gets them cleaned regularly or there upkeep on their fuel system might be lacking. I've had many customers come with me with used injectors that are nothing but a headache.
 
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