Replaced L03 with an L31 in my Firebird and it has been a tuning nightmare ever since

Ok, so the bias is what had me confused when I look at other calibrations that use a different mask. I only see knock counts after the startup test (sometimes not) and in the higher RPM range say around 4000 and above. I know that the knock system operated well before the swap, but I don't trust it now. I would say the new sensor is probably just fine, but since they are for a 305 and not a 350 they just aren't accurate. I believe that the bias is only added in TP when the .xdf is set up that way. The .xdf I use is supposed to have the bias already added into the spark table. And thanks for clearing up the difference in in where the code is stored in c3 ecm's vs. p4 ecm's. If I don't figure out a multi port intake solution soon I am just gonna go ahead and upgrade to a 7427 pcm. I have been holding off because I really want to run a pcm capable of properly running multi port and controlling an electronic trans such as a 4l60e. Well, I need to head to bed, but thanks again for the help. I still have a few questions regarding some of the tables in the calibration and how to modify them properly to make the ecm do what I want.

Phil

Sorry Mark, I just now read your last post. You must have posted it while I was typing my last post last night. But, to answer your questions, the base timing is at 0 with the EST/Bypass connector disconnected. With the engine idling at ~650 RPM's in park at operating temp and the EST plugged in the timing was ~27 degrees and that is correct for the bin you are looking at given that the ecm takes the average of 4 cells. So, yes I guess I am running a buttload of advance and didn't realize it due to the reasons listed in my last post. What is wierd is that the engine seems to run better with that spark table vs. the stock ANTT table. More to say, but gotta put the baby to bed for now.

Phil

Well yeah it may seem to run better, but for how long? You had mentioned blistered plugs!!! Your a tech so I'm very intrested what happens with this and in the end we get a correct $61 XDF or at least a *Read Me* note on the timing paremeter since there 2 I know of floating around.

But as you said 27 degrees advance at idle? That's pretty high, have you seen anything comparable ever run that much? I haven't... would have to drop at least 10 degrees when accelerating to start the climb back up right?

You are absolutely correct on the knock sensor, they are specific to cubic inch, then there are also some differences in the ESC. I never mix and match so have no knowledge of differences, there was a good write up from Grumpy on Thirdgen from many years ago when he did some testing. I just stuck with matched sets from like cubic inch engines.

Well Mark, there are just so many oddities with this setup that it has me all mixed up at this point. I am going to attach my xdf and latest tune to this post for your reference and address a few of your questions, but I gotta get running for the day so the rest of what I have to say will have to wait. The xdf that I am using is straight from the TP website and was made by Jon Prevost. I have made the necessary modifications to the xdf to allow for maptrace to function and that was very recently after I stumbled across the "how to" in the help tab for TP (who would've ever thought to look there for instructions? lol). As I previously stated, until I performed this engine swap I had barely tapped into the potential of TP since I was only tuning basically stock engines to run on E85. (And on that note, I haven't even considered running this engine on E85 until I can make some sense of what's going on, so we are strictly talking about tuning for gas.) I really have learned volumes since my original post and you will see in my latest tune that, while the timing values are similar, I actually used a vortec based tune that I downloaded and altered it to better fit what I know works for this setup. Back to the quite odd issues I am having, though, the timing at idle was ~27 degrees, but the RPM's could have been as high as 800. But, yes it did run fine with that much advance at idle, and no I haven't seen anything run that much that I can think of. I am going to have to definitely go back to the basics on this one starting with using a different timing light to ensure that mine is accurate. Technically it should be accurate as it is only a couple years old and has seen VERY limited use, but I am not willing to rule out anything at this point. I only look at knock counts as sort of a reference because I am positive that the 305 setup currently on the car is unreliable at best. The correct parts are in the plans to be installed asap, but money is an issue right now so it's just gonna have to wait.

Didn't see any attachments but Jon Prevost is a good name for tuning, now is his the XDF with or without the 20.04 degree bias? And yes I would not trust a 305 Knock sensor and ESC in a 350, not at all!

But yes if you post your XDF, bin and possibly a data log in XDL I would like to look and see what is going on?

Then when you have time can you start a thread on E85? I don't think we've touched the subject and something I am intrested in.

Sorry, I got in such a hurry that I forgot to attach the files yesterday. The xdf on the TP website is $61v3 and when opened in notepad it says that the 20.04 degree bias is calculated into the spark table. I will copy my last log and change the extension to xdl and see if that works, but if not I will just have to log a drive using TPv5 and upload it. As soon as I can I will start a thread on E85. I started experimenting with it 4 years ago after doing tons of reading on it. I will say that even today there are still myths and conflicting information surrounding ethanol when used as a fuel. But, after using it in 3 different vehicles and racking up around 100k miles, I feel that I can confidently speak on the matter of what is true about it and what is just plain lies. I do have a lot to say about some of the quirks the car has and a lot of questions about some of the tables and whatnot that affect how the car runs. But, as always, I don't have time at the moment so I will have to wait until another time.

Phil

OMG not much in the $61... I'd upgrade to the 7427 now and save some headaches.

That log will not open in TP V5... but comparing the spark table to a stock ANTS F body you have between 8 and 17 additional degrees advance in areas that count.

I also noticed stock ANTS had max spark allowed of 40.08, I think this is a large cap EFI distributor as small cap is usually 41.84. So spark latency table could be off as much as 11 degrees to...

Fueling VE was overall less and BPW was lowered so I'm guessing you have an increase of fuel pressure.

I noticed on my other laptop that the log wouldn't open in TPv5 which means that I will just need to log a drive with TPv5 in order to have a log that you can see. The tune that I have originated from an ANTT image that I copied from another nearly identical firebird that I used to own. The spark latency table has not been touched and both used small cap distributors. I did, however, limit max advance to 36 degrees. The fuel pressure is still at around 30psi (constant 30psi now as I disconnected the vacuum reference) so even with the 305 injectors the BPW and VE tables will be lower. I have adjusted the VE tables to keep the BLM from jumping around a lot, but they are still not perfect. You may notice that the main VE table is a little choppy, but I have only altered the cells based on logs and a lot of the cells just don't get used. I know that the timing still looks aggressive, but there are a few things to factor in here. First, the engine only sees a max of 4500 rpm and mostly stays under 4k so I am looking for max advance around 4k as that's where peak power is. During highway cruising the RPM's range between 1800-2200 RPM with 2200 RPM equaling about 80mph I think. Second, the car runs like a dog with less advance than this. I believe that before at the beginning of this thread that the timing at WOT was where I was encountering issues with detonation. And lastly, I know that when comparing the spark to a stock calibration it looks pretty aggressive, but when compared to many custom tunes for similar engines it falls right in the middle with some being more aggressive than mine. I think that there are a few reasons for requiring so much timing. The car has the "power bulge" hood that is essentiallly a cowl induction style hood and it has a removable plug that I leave removed that does supply a lot of cool air right to the throttle body. Also, the intake has no EGR or hot water passages save for the front crossover so it stays significantly cooler than an OE setup especially given that I am running a 160 degree thermostat. And as long as the car is moving the temp stays right at 160 too. Those factors along will allow for more timing, but I also believe that there may be something fishy in the electronics somewhere because it seems that even the old LO3 liked more timing than stock. I have a few theories about what's going on and there are a LOT of components that could be causing these little gremlins. At this point, I am going to try to nurse the car along without ruining the engine and slowly gather what I need to replace the ecm with a '427 unit and also install a new distributor and some upgraded plug wires and a hotter coil. (the better ignition components are for E85, but aren't a bad idea on anything imho). I still would like to upload a log that you can view and give your opinion on and will get to that asap. I haven't accomplished anything the last couplee of days as I have been laid up in bed with bronchitis, but hopefully it'll be gone before long.

Phil

Okay, so after all of the heartache I have found that at least part of my problem or actually problems are the ecu is crapping out on me. So, the reason that I was having inconsistencies all around was because the ecu is probably just doing whatever it wants. Bad news is that I also appear to be experiencing a mechanical malfunction in the engine as well. I know for sure I have a few bad lifters that are causing issues, I just don't know how many issues at this point. Right now that leaves me with a couple of repairs to make and also a little research. Right now would be a perfect opportunity to swap to a 427 pcm, but I need to find out if they can operate a tcc solenoid on a th700r4 or not.
Well, it's off to bed for now, but I'll post my findings as I progress.

There's info in the $0D XDF for running 700R4.

Quote:

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Originally Posted by EagleMark

There's info in the $0D XDF for running 700R4.

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Excellent, I figured that there would be some way to make it work. I just had never looked into it as I have had a 4L60E upgrade in the plans for a long time now and was just going to do the PCM and tranny at the same time. I'll be acquiring a PCM asap and already have a memcal adapter I just need to find a memcal with the correct knock filter. I still have to investigate the root of my mechanical issue, but I'm going to inspect the short block that I have on my stand now to see what it needs. I don't feel that the one in the car is worth investing too much time or money into attempting to repair when it already has that many miles on it. If the bottom end of the engine on the stand is in decent enough shape then I'll just re-ring it and install new bearings. If it needs a crank kit and the piston to cylinder wall clearance is too sloppy then I will re-evaluate the situation then. Somewhere along the line I am just dying to find an opportunity to slip in this LT4 hot cam that has been taunting me ever since I bought it 2 summers ago. But, back to the main topic, I will still post what my ultimate findings were once I have solved all of the puzzles. Also, I finally hit on a really good tune with the timing and VE tables right as I started finding my problems too. I'm on the wrong laptop again so I don't have the latest bin, but I reworked the timing table a little and pulled as much as 6 degrees in some areas. I don't know how or why, but I believe that the only reason that the engine didn't sound like someone ringing the dinner bell under the hood with that much advance has something to do with the bad ecm. Anywho, since I am feeling in the mood, I am going to go ahead and start that ethanol thread that we discussed since I believe we have beaten this dead horse long enough :mad1: