Sam@RRE said:

I can see how a faulty CAS would effect fueling, if the ECU was seeing a lower RPM value than actual RPM, then the Speed part of the Speed-Density calculation would be off.

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Yeah... but it's damn strange how it affected such a narrow pulse width and created that spike. And the logged RPMs were solid and matched the tach; in fact the only symptom I had at all was crazy retarded timing (and the resultant high EGTs) for no apparent reason...but even that didn't show up until later.

Sure looks like that was it though. Every time I run the CombinedFT tool (or work on it manually in open loop), that area at 2500 keeps smoothing out and blending into the 3k column like it should.

I've swapped between the original 1250's and the loaner 1350's from FIC a couple of times, and it was definitely a strange CAS issue and not the injectors. The car runs smoothly now on either set, and the VE table looks much more like it should.

I would like to thank Jens from FIC for the fantastic customer support (as always), and to you guys for the excellent discussion during this strangeness.

I've gotta say. Big ups to FIC for putting their neck out and standing by their product and loaning you a test set. Glad you got it solved Craig.

Glad to see you finally found an issue to put this to bed!!! WEre you able to tell in any other way that there was an issue with the CAS or was it really something where you just had to swap them, do some logging and watch the tune and see if anything changed?

Really a ghost in the machine with this one

I forgot to update this thread a while back, but it turns out that it wasn't the CAS after all. Although the CAS was definitely bad and caused some timing and AFR inconsistencies, it wasn't the source of this crazy lean spike.

After swapping the CAS, I was able to smooth the VE table somewhat but was never able to completely elminate the spike. Soon after that, I had bigger fish to fry with a clogging pump issue...so I switched from E85 to gas which also seemed to mask the spike somewhat.

A few days ago I went back to E85 and started over on the tune with a different set of injectors, and the lean spike is back and bolder than ever. Here is what my VE table looks like when I get everything adjusted for decent drivability:



Is that not crazy? It always happens around 2600 to 2800 rpms, and the pulse width now seems to be around 4.5ms or so at the spike. It's much more noticeable with higher TPS deltas and during shifts, but it's still there even with a slow continuous ramp from 2k through 3k or so. FWIW, the car runs excellent in all other operating areas of the map.

Here is what has changed, with no (or very little) affect on the spike:

Two different pumps (W255hp and a DeatschWerks)
Three different CAS's (although two were bad and caused other issues)
Different PTU
New coils for COP
Two sets of injectors (FIC Blue Max 1250's and Blue Max 1350's)
Two different fuel filters (Golan and Earl's)
Different plugs and gaps
Different fuel base pressure (37 to 45)
Different timing curves
Different AFR targets, both open and closed loop
Tightened cam/valve overlap
Widely varying ambient temperatures, IAT's, humidity, etc.
Different fuels, including WAI (although beyond the operating range of this anomoly)
Voltage is very steady at 14.2 to 14.4, never dropping below 13.8

About the only thing I haven't done is change the air filter or run it without one....but I think that's next.

Just a thought.... Since I dont see a log

What does your Da fuel map look like?

An What are your openloop thresholds set to?

OL thresholds are slightly higher than stock, DA AFR tables are basically stock except leaned out and smoothed a bit more.

But... I see the same spike whether I'm reading AFR targets from the DA tables in open loop, or trying to maintain stoich in closed loop. I've even richened up the AFR targets in that area to increase IPW while locked in OL, and I still see the spike... although it does change somewhat as expected.

I think I have a recent log, but it won't show much since that crazy VE correction is compensating for it.

Calan said:

Two sets of injectors (FIC Blue Max 1250's and Blue Max 1350's)

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This ^. Try a different injector. I'll have a set of 950's you can borrow/test after this emissions crap passes over, they're FIC 950's but not Blue Max's. You changed them but I don't think going from a BM 1250 to 1350 really consitutes a big enough change to move onto the next idea.

Craig is going to have a full set of injectors from 450 to 2150 next thing you know it I offered to pull my 1150's for him as well.

gofer said:

You changed them but I don't think going from a BM 1250 to 1350 really consitutes a big enough change to move onto the next idea.

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Yeah... I'm thinking the same thing. You may have seen in Chris's thread that Brian has a set of 1150's he said he could loan me also. Whatever I drop in, I want to have Tom test them first on the new rig, so I have some solid latency and flow numbers based on the DSM ECU drivers to work with.

EDIT:

Freakin' ninja mod.

snowborder714 said:

Craig is going to have a full set of injectors from 450 to 2150 next thing you know it

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If you'd like to just send me a loaner set of 2150's that I can keep for as long as I want, we can just cut right through the crap and I won't need to collect the whole set.

Calan said:

If you'd like to just send me a loaner set of 2150's that I can keep for as long as I want, we can just cut right through the crap and I won't need to collect the whole set.

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^ HAHAHAHA I have a set of Delphi 950's sitting on the shelf to help with your never ending problems. Let me know if you want to try.

Robert

Calan said:

I want to have Tom test them first on the new rig, so I have some solid latency and flow numbers based on the DSM ECU drivers to work with.

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The offer is still open. Send 'em in and I'll strap 'em down and see what you've got to work with.

Thomas Dorris

Cool deal. I'm thinking we test Brian's 1150's, and then I'll drop them in and send you my 1350's.

Appreciate the help. I'm really curious to see what is up with these things. That spike is pretty bizarre huh?

For future reference....

I installed Brian's 1150's and used Tom's numbers for them, and sent my 1350's off for testing. The lean spike issue pretty much went away; I was still a bit leaner in that area than I would expect, but not by much and it was smooth.

Using the numbers I got back from Tom on my 1350's, I got about the same results as with Brian's 1150's. The injectors required from -60 to +40 on individual DT, and the DA voltages were very different than those published by FIC. Using Tom's values, the car runs MUCH better and idles like a purring kitten with no misfires whatsoever. As of the last few tuning sessions, the lean spike is gone and the VE table looks much more like it should.

I HIGHLY recommend that people contact Tom about possibly testing their injectors on his new rig.

That's a lot of deadtime to have inbetween injectors so much for being "matched"...
But doesn't really surprise me with as many issues people have dialing them in(That know what their doing)

Do you happen to have the original latency values that can with the injectors? VS what Tom's results were? I know a lot of people have to run more deadtime they they list them as (myself included) probably has alot to do with our old injector drivers with their FIC BM's. I picked mine up Used so IDK what the should have flowed or the latency values Just dialed them in myself.

MY1GDSM said:

That's a lot of deadtime to have inbetween injectors so much for being "matched"...

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Yeah; I was quite surprised.

I have nothing but good things to say about Jens and FIC, but there is a lot to be said for characterizing DSM injectors using DSM drivers and Tom's custom software. The difference in performance once the individual DT and correct voltage latency values were plugged into Link is nothing short of amazing, at least in my case. He also found one injector that doesn't flow the same as the others, so with a better flow-matched set the performance may even be better than what I'm seeing now.

While the 1350's were out, Brian's 1150's with Tom's numbers just dropped in and felt like stock 450's.

MY1GDSM said:

Do you happen to have the original latency values that can with the injectors? VS what Tom's results were?

Click to expand...

I'll see what I can dig up. Tom has been posting numbers for several tested sets in this ECMTuning thread, but those are still just starting points. Nothing beats having the actual set tested and sent back to you with the injectors labeled and matching numbers to plug in.

MY1GDSM said:

I picked mine up Used so IDK what the should have flowed or the latency values Just dialed them in myself.

Click to expand...

I thought I had tried every DT and voltage combination known to man on my 1350's, but I was never even close.

I'm still looking for the original FIC data, but here are the values that Tom recommended for my BM 1350's:


I'm using these exact values, except for global fuel which has been changed to compensate for different fuels and my base pressure.

It's all in the individual DT adjustments and voltage values. It's just impossible to hit on the right combination unless you have a setup like Tom does to actually see what is going on with pulse width and injector events, and can accurately measure them under stable conditions.

I should be able to look up my original values FIC recommended and post them up along with the values from Tom in the next couple days if you'd like.

I'm pleasantly surprised at the reports so far. It seems like this stand might actually be doing some good after all.

If anyone is wanting a good read on what we're learning and trying to do here, this page is a good starting point.

injdata-overview [ECMTuning - wiki]

Although I appreciate Craig's suggestion that people get their injectors tested, we're not quite ready for that yet. We've been doing a few sets "by request" for a while now just looking to get the bugs and process worked out first.

To share another similar data point, we had a customer stop by a couple weeks ago with his FIC 1150s in hand. Brand new, in box, unused. He wanted to test them out and swap them in while he was here. It provided a great chance for us to get some hands on before/after on an actual customer car.

The results were surprisingly good. We did our normal full-sweep test and got him his individual deadtime numbers, flow rate and battery tables all setup then fired the car up. It really did idle like stock. We were all pretty surprised to be honest.

But we weren't sure if the injectors were just nice or if the individual deadtimes were working. So we decided to remove the individual adjustment and just run a fixed base like one would normally do. The engine was DEFINITELY not running as smoothly as before. So we grabbed a couple logs to illustrate.

One was done with individual deadtime adjustments and the other was without. The O2 sensor is a good indication of how well the engine was running. All those little ragged edges are misfires that you could also hear and feel. It wasn't like it was shaking the car apart or anything. It just clearly wasn't the smooth idle he had with the individual deadtimes dialed in.

Thanks for jumping in and posting Tom. Those log captures are an excellent example.

twdorris said:

Although I appreciate Craig's suggestion that people get their injectors tested, we're not quite ready for that yet. We've been doing a few sets "by request" for a while now just looking to get the bugs and process worked out first.

Click to expand...

Well, in my defense I did say:

Calan said:

I HIGHLY recommend that people contact Tom about possibly testing their injectors on his new rig.

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Nice, that looks like some really good logger proven results right there. This should definitely have a big hand in the longevity of a motor at higher HP levels. Just think about what all that spikey junk would be doing at 9k rpms.

Hopefully Craig doesn't consider this littering up his thread

Here's my data from FIC and from Tom on my 1150 injectors.

FIC Data Flow Sheet







Numbers and Graphs from Tom


Single deadtime applied



Numbers above applied



Numbers above applied, full flow range shown

Brian, did you cut off the injector voltage offset table on the bottom of the data sheet from FIC? I was interested to see what their recommendations were compared to the InjBatteryAdj settings ECMLink sent you.

With high-Z injectors, as you know, you eliminate the resistor box so the FIC injector voltage offset values are a good place to start.

That's all that was on the sheet I was given

Maybe back when I purchased them they weren't supplying that info? I'm not sure if they have that data on hand for past sold injectors that I could contact them and get it, or if all of this stuff is just made up before injectors are shipped and that's it.