The SAVE MY ENGINE! thread. A SAFE place to post logs and get feedback.

[gmtech16450yz]

There's been a lot of discussion about blown engines lately on here and other forums. One of the common themes, as far as MY opinion goes, is that a lot of guys didn't know they were in danger of major engine damage or complete destruction before it happened. I've been trying to stress logging, and logging often, but not everyone that has the HPTuners hardware is, or wants to be a "tuner". They might just want to have somebody look at what they're logging to make sure it looks "safe". This thread (hopefully) will be for that.

I emphasized "a safe place" because I want everyone from experienced tuners to total rookies that just got their scanners to feel comfortable posting logs, screenshots of logs or even tune files here. This isn't a place for judgement or berating anyone for what their "tunes" may or may not be. This isn't a place for free advice on how to make your dyno numbers higher either. I'm really hoping this is a place that ends up saving a few guys some major cash in engine repairs or replacement.

A lot of the logs I've seen have been super obviously dangerous just by taking a quick look. Those are the ones that I feel really good about seeing and warning the owners to fix BEFORE it's too late. I truly believe at least half of these engine failures can be avoided just by logging and having somebody look at the logs. So many guys leave their tuners or shops and never think about logging or that their tune might "change" over time. Maybe their tuners warned them when they left, but who's actually listening when all they want to do is feel that new found power?! There's also a bunch of people that have PM'd me because for many different reasons, they just want to learn how to keep an eye on their own logs and make minor tune changes even though they know almost nothing about "tuning". That's ok, in fact that's AWESOME! Learning is great, and learning things that are outside of your normal realm or comfort zone are the best! So again, hopefully this can be a place for guys like that to get help. We ALL need help on this stuff, and we ALL can learn from each other, me included.

So if you're that guy that wants to make sure you're not in imminent danger of destroying a very expensive engine, or just wants someone to look over some logs to see what the "experts" think, post away! No judgments. No tuner or shop slamming. No shaming in what your logs look like. Just helpful, constructive criticism and advice. And yes, it's OK if you don't have a wideband! I realize not everyone does, for a myriad of viable reasons. Just try to log everything that's needed, which btw can certainly be included here, Layout files. That's another thing that not everyone knows, and it's TOTALLY understandable. What to log is a question that d@mn near every tuner, new or old has. That advice can hopefully be shared here too. In 3.0 you can basically have it show all the supported parameters of the car you're working on when you connect. If all else fails, log 'em all!

Thanks guys! Hopefully this helps some guys save some money. I must add though, I TOTALLY understand if blowing your engine is the easiest way to get your wife/girlfriend to let you spend a ton of money on a sick new engine build! If you want to post a log to make sure your engine ISN'T safe, I guess that's ok too!

[JBZ]

thank you gmtech for creating this thread, this may be my engine saver thread. hahaha

To those who are curious I own a 2010 CTS-V A6 with 2.4 pulley, ID850's, headers, ZL1 lid and track attack heat exchanger. I did all the install myself of all the parts over Christmas vacation and took it to a shop to tune in early January. when i took it in i was getting some pretty bad fuel pressure drop and ended up replacing the fuel pumps. that did resolve the fueling issue. so that prompted me to start logging on street runs to see when i needed to get out of it (before i had the pumps replaced) and wound up with another issue i have been chasing ever since...some pretty bad KR. of course i have done all the usual things like check spark plugs, swap coil packs to see if the KR moved with the coil pack, checked plug wires and all seemed well until i came across something that i had passed over while doing the injectors. the injector wires were all botched, all i can think is someone (previous owners shop i would guess) put on none USCAR connector set of injectors then went back to stock. well im now in the process of replacing my injector harness on both side. i have not received the driver side yet but got the passenger side one last week and the drive side should be in this afternoon.

so i was getting up to 6 deg of KR and mostly on Cyl 6 previously or i should say Cyl 6 was the highest. after the injector harness install (and the logs are post install) the highest KR has now moved to the other side of he engine. i am hoping that the harness is the main culprit in the KR but honestly don't know tuning enough to be absolutely sure.

another issue that i am having is on idle surge...bucking when i have the brake applied but allowing the car to roll forward. this only happens in 1st gear (when i have the shifter in sport mode) and it did not happen before the tune. keep in mind i have a stock cam so i don't think i should be getting any bucking.

i have attached my logs and tune file and would love to have the experts take a look and let me know their thoughts. And guys bare with my novice-ness, stupidity or questions i may have. i am a novice tuner...well actually not a tuner an owner and someone who just wants to have fun but not at the risk of a blown LSA. i would like to add that i am open to any advice you guys give, if there are tune changes, things i should be logging that im not, things i don't need to log...what ever it is.

[Niemer]

Cool, great idea. I have one that actually is a known issue on this board and affects quite a few people. The lean spike 2 seconds after entering PE. This has affected me for a couple of years now and every attempt to rectify it has done exactly nothing, I've been operating under the assumption that since it happens and is over, usually, in ~0.375 seconds that it won't effect cylinder temperatures enough to be a concern.

This log shows the spike 2 seconds after PE is first commanded, you can see boost enrichment kicking in shortly after the initial PE. This also shows a little bit of knock at the same time, but that is not common. The duration of the spike seems to correlate with airflow, greater airflow usually means a shorter duration.

[Niemer]

.

Your injector flow rate doesn't match the data ID provides, all the other injector parameters look right though.

Your MAF and VVE tables are a little choppy, though, not terrible.

You have a lot of timing in the idle areas of the main spark table compared to your idle spark tables, you might try bringing those closer together.

[Earwax]

Hi,as a recent HP purchaser.

[JBZ]

Your MAF and VVE tables are a little choppy, though, not terrible.

You have a lot of timing in the idle areas of the main spark table compared to your idle spark tables, you might try bringing those closer together.

Niemer thanks for taking a look,

I have a few questions regarding the data in the injector flow rate comment you made. first off I assume you are referring to the injector flow rate vs pressure delta? I have attached a few pictures just to be sure these are both the tables that you are referring to. one from my tune file and a highlighted row from the ID spreadsheet (am I looking at the right row in the ID spreadsheet?). if it is, and I change it to match...will this be a problem seeing as how I don't yet own a wideband? should I only change this after I have purchased one, im just worried that could affect my AFR? excuse my question but I really don't know. I also know it doesn't matter because my fuel pressure is limited to about 75 psi but on he upper end of the frames where the ID spreadsheet call for anything over 127 lb/hr (99 PSI) I am limited to 127lb/hr in my tune file.

delta psi.pngUntitled.png

edit, I have also attached a screenshot and log from this mornings drive into work. I did get a little KR (2 deg) no where near as bad as it had been and I replaced th driver side wiring harness last night. I plan on making another log on the way home today and hopefully can have a chance to get on it. these damn Houston streets are busy.
pull this morning.pngstreet log from 4-7-16 morning, KR at fram 40316.hpl

[Niemer]

Yes, that's the table. The pressures listed across the top is the pressure drop across the injector, which takes into account MAP. So, if your fuel pressure is 50psi and your MAP is 60kPa (~5.6psi vacuum) the pressure across the injector is 55.6psi or 404kPa since the vacuum in the manifold is pulling fuel out of the injector. Now when you are in boost the opposite is true, lets say 50psi fuel pressure again, but 190 kPa MAP (~13.3psi boost) the pressure across the injector is only 36.7psi or 253kPa since the positive pressure in the manifold is trying to push the fuel back into the injector.

So, in sort, the only way you'll ever see 99psi across the injector is if your running 75psi fuel pressure and somehow manage to get less than 0kPa MAP.

It could affect AFR since the ID values are all about 5lb/h higher than what you have.

[JBZ]

Yes, that's the table. The pressures listed across the top is the pressure drop across the injector, which takes into account MAP. So, if your fuel pressure is 50psi and your MAP is 60kPa (~5.6psi vacuum) the pressure across the injector is 55.6psi or 404kPa since the vacuum in the manifold is pulling fuel out of the injector. Now when you are in boost the opposite is true, lets say 50psi fuel pressure again, but 190 kPa MAP (~13.3psi boost) the pressure across the injector is only 36.7psi or 253kPa since the positive pressure in the manifold is trying to push the fuel back into the injector.

So, in sort, the only way you'll ever see 99psi across the injector is if your running 75psi fuel pressure and somehow manage to get less than 0kPa MAP.

It could affect AFR since the ID values are all about 5lb/h higher than what you have.

So in your opinion would that raise or lower AFR. that's where im confused as to how that table is used for fueling. my assumption would be that modifying the table to follow what ID has in there table would richen up the mixture. am I right in thinking that?

[gmtech16450yz]

So in your opinion would that raise or lower AFR. that's where im confused as to how that table is used for fueling. my assumption would be that modifying the table to follow what ID has in there table would richen up the mixture. am I right in thinking that?

The easy way I think of it is if you double the flow rate, you're telling the ECM the injector flows twice as much. So to keep the same fueling levels, the ECM would have the injector on half as much. So if you change the flow rate to a higher value, it would lean out the mixtures. (Assuming the tune has already been dialed in for the lower, incorrect values.) It's a table that lets the ECM know how much fuel gets injected for the amount of time it has the injector open for. These values CAN be tweaked away from a suggested value like those from ID, but usually it's best to have them what ID says.

Sorry to not get back in here right away guys. As usual, I'm kind of a hit-or-miss forum poster. If I'm deep in the middle of a project, it might be a few days or weeks until I get back to the forums. I'm SOOOO freakin happy that others have jumped in already!!! I don't have all the answers anyway, h#ll a lot of the time I don't have any! That's what's awesome about this forum, we all have our special pieces of knowledge. So if one guy doesn't have the answer, somebody else probably will. I love it! Thanks guys!

[JBZ]

The easy way I think of it is if you double the flow rate, you're telling the ECM the injector flows twice as much. So to keep the same fueling levels, the ECM would have the injector on half as much. So if you change the flow rate to a higher value, it would lean out the mixtures. (Assuming the tune has already been dialed in for the lower, incorrect values.) It's a table that lets the ECM know how much fuel gets injected for the amount of time it has the injector open for. These values CAN be tweaked away from a suggested value like those from ID, but usually it's best to have them what ID says.

Sorry to not get back in here right away guys. As usual, I'm kind of a hit-or-miss forum poster. If I'm deep in the middle of a project, it might be a few days or weeks until I get back to the forums. I'm SOOOO freakin happy that others have jumped in already!!! I don't have all the answers anyway, h#ll a lot of the time I don't have any! That's what's awesome about this forum, we all have our special pieces of knowledge. So if one guy doesn't have the answer, somebody else probably will. I love it! Thanks guys!

cool thank you sir for letting me know...think for safe sake I will keep them how they are for now and once I have a wideband in place and can monitor AFR will change accordingly. by the sound of if the tune has been dialed in for what it is now there is probably no need to change it.

[gmtech16450yz]

cool thank you sir for letting me know...think for safe sake I will keep them how they are for now and once I have a wideband in place and can monitor AFR will change accordingly. by the sound of if the tune has been dialed in for what it is now there is probably no need to change it.

That sounds like a safe approach. It's ok to not know, there are so many factors that come into play on many of these tables.

One thing to remember when you're experimenting with any tune is to ALWAYS have a safe place to go back to. If you haven't already, do a full read on your car and save the file in a couple places under a name that makes sense to you. I name tune files and logs with descriptors that help me later like "Sky LSA tune 378 raised injector flow rate 5 percent" or something like that. So if I F up, I look for the one that said something like "Sky LSA tune 555 Best tune ever runs awesome". lol. I'll open the tune that's currently in the car and then open that old file as a compare file. Look at the Comparison Log and see what you changed that made it run badly or do something weird. Then I either cut the differences in half or go all the way back to what worked by "Copy over differences". As long as you have a safe place to return to and know how to return to it, it's perfectly ok to experiment. Just be careful by logging and avoiding stuff like long WOT runs until you know it's ok.


BTW- on your KR, do some reading on knock retard decay speed. One thing I noticed is the decay speed looks like it's stock, which is pretty long. You can try shortening that decay up so you can see if the knock is once or continual. As long as the rest of the knock retard settings are stock or safe, shortening the decay won't hurt anything. If it sees more knock, it will just keep spiking up the retard. When the decay is long, it could be one single knock that retards the timing for as much as 10 seconds.

[gmtech16450yz]

Niemer, sorry to ignore you! I do have to actually get some work done this morning but I did have a couple of quick thoughts.

What's the fuel pressure look like when this happens? If you don't have a factory sensor, get an aftermarket sensor and input it into HPT through the MPVI inputs. I'd like to make sure it's not a pressure/regulator issue. Also, have you messed with transient fueling at all? It's almost like the transient fueling is ok but right after it decays the "main" fueling is too lean? Kinda like an accelerator pump making it rich enough, but for too short of a duration of "squirt". (There's nothing worse than having a short squirt duration. haha) Anyway, just a thought. It is kinda weird and shouldn't do that. I'm assuming everything else is telling you that you can trust the PLX readings? Is it a 4.2 or 4.9 sensor?

[Niemer]

cool thank you sir for letting me know...think for safe sake I will keep them how they are for now and once I have a wideband in place and can monitor AFR will change accordingly. by the sound of if the tune has been dialed in for what it is now there is probably no need to change it.

That would be the safe bet, gmtech is right, it would lean the mix out, but by how much is hard to say. I really wouldn't touch a whole lot without a wideband.

[cc-rider]

Cool, great idea. I have one that actually is a known issue on this board and affects quite a few people. The lean spike 2 seconds after entering PE. This has affected me for a couple of years now and every attempt to rectify it has done exactly nothing, I've been operating under the assumption that since it happens and is over, usually, in ~0.375 seconds that it won't effect cylinder temperatures enough to be a concern.

This log shows the spike 2 seconds after PE is first commanded, you can see boost enrichment kicking in shortly after the initial PE. This also shows a little bit of knock at the same time, but that is not common. The duration of the spike seems to correlate with airflow, greater airflow usually means a shorter duration.

Niemer,
Do you have your dynamic prediction coefficients zeroed out? From what I could gather reading other threads...these prediction coefficients were wreaking havoc in various different ways on modified cars. Many people have gotten rid of weird issues like you are seeing by zeroing out these. Mine are zeroed out...I get no weird PE afr changes during a pull.

[Niemer]

Niemer, sorry to ignore you! I do have to actually get some work done this morning but I did have a couple of quick thoughts.

What's the fuel pressure look like when this happens? If you don't have a factory sensor, get an aftermarket sensor and input it into HPT through the MPVI inputs. I'd like to make sure it's not a pressure/regulator issue. Also, have you messed with transient fueling at all? It's almost like the transient fueling is ok but right after it decays the "main" fueling is too lean? Kinda like an accelerator pump making it rich enough, but for too short of a duration of "squirt". (There's nothing worse than having a short squirt duration. haha) Anyway, just a thought. It is kinda weird and shouldn't do that. I'm assuming everything else is telling you that you can trust the PLX readings? Is it a 4.2 or 4.9 sensor?

Fuel pressure drops right when this happens, for a split second, actually kind of hard to catch in a log. Narrowbands confirm that this is real, IPW stays constant. There has been a ton of effort put into solving this issue by myself and others, it shows up on a bunch of e38s with a bunch of different mods, even stock. There is something that we don't have access to that is causing it that is triggered by entering PE, it doesn't happen if PE is disabled and enrichment is built into the tune.

http://www.hptuners.com/forum/showth...pot-during-WOT

[Svh19044]

What else should I be logging? And why can I not get LTFT's to log?
CTS-V A6 with 2.4/headers/high flow cats/id850 injectors/CAI/heat ex/on 93 octane plus boostane

[Niemer]

LTFTs are disabled in that tune.

[Svh19044]

It was set to 284 min ECT (I guess obviously why it wasn't recording). What is the correct temp setting or is this done for a reason? I guess different tuners disable them, and my tuner is one. The car runs great, but this is a thread about saving engines, so it's worth asking.

[Niemer]

Mine stock are 131 min 284 max

[Kmeadows]

This is my first time doing a major overhaul tune, i have done some basics before but nothing to this extent.

2007 Yukon Denali E38 controller
6.2 L 80 lb injectors, twin S366's, LJMS Stage 1 Camshaft 222/227 .602"/.598" 113+3

So far seems to be dialed in OKAY its not safe and it seems that no matter what im doing its not helping.

I had it set to 4PSI while i dialed everything in in the lower portions of the VE, recently turned it up and after using the AFR Error im really not able to get the table to smooth out at all, its very spikey and if i go through and manually smooth it out the AFR's are way off.

Also torque management was pulling timing down to 0 sometimes -2 so i set the min timing to 10* in the last flash, but now im registering a LOT of KR.

Here are a couple logs from today and also the latest tune file.

Please tell me how jacked this tune is and if possible point me in the right direction. Cold start also sucks and Ive tried adding airflow into the start up tables and it does not seem to help much if at all.