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DFI and ECMDiscuss all aspects of DFI (Digital Fuel Injection), ECMs (Electronic Control Module), scanners, and diagnostic equipment. Fine tune your Third Gen computer system for top performance.
Hello All. I have a 1991 Trans Am with a 5.7L using a 7730 ECM. I've been having some driveability/timing issues and I'd like to be able to do some data logging in the attempt to see where things are going wonky. I recently purchased a ALDL Scan Cable from Red Devil River. I also just downloaded Tuner Pro RT V5. Now the fun part.....getting it up and running.
Could someone please tell me exactly what files I need and where I can find them to data log? ADX/ADS/BIN? I'm not currently looking to burn my own chip, I just want to see what's going on.
I have searched though the thirdgen forum (awesome source of info on everything so far), but I am getting a little confused. I'll read something and think I know what I need, but then the links are dead and/or I can't find the file I'm looking for.
Once I have the files, can someone also give me a basic step by step to get Tuner Pro RT up and logging?
Thank you very much for the info. I downloaded the suggested files and got Tunerpro RT to start logging. This was just a simple test log done in my garage and lasting about 2 minutes. I rev'd it a couple of times, but nothing above 2500RPM, and that was just blipping the throttle. From the attached pictures, does anyone see anything crazy? Knock Count seems to be pretty high. I'm getting a big time exhaust smell so I'm also wondering if the exhaust doughnut is shot.....maybe causing increased counts?
I have the .csv, but it's easier to watch the data in real time...
You just have to find the directory where the xdl files are being saved and then send me the xdl file.
Any rate, what I"m seeing so far is that your BLM's start dropping dramatically when the engine RPM starts increasing. Not sure what's causing it at the moment...
The engine was rebuilt. Had an issue with the distributor and had that replaced. Engine would bog down really bad at about 2000 RPM....especially when in open loop. It would get better when in closed loop. Took it to another place for diagnosis. They told me the original place installed the new distributor 2 teeth off. They think the original place compensated for it by playing with the distributor cap timing setting. They also did a compression check, fuel pressure check, and smoke test (for vac leaks).
But....once the distributor was set properly and retimed, it ran 99% better. However, the next day, some of the engine bog started coming back, but no where near what it was before. At this point, I'm at a loss as to what the issue could be.
Things that have been done/replaced:
Rebuilt motor (claimed they put in a slightly different cam, but I didn't get any specs.....makes me think they didn't touch it. If they did, I would imagine the stock PROM fuel table setting could be off)
New ECM
New Distributor
New Cap/Wires
New Ignition Module
New EGR Solenoid
I was going to go and take it for a quick drive and log that info. Would you mind looking at that data and let me know what you may think is going on?
Here's the latest .csv data log file. I drove it about 5 miles at different RPMs/Speed/Level of thottle input. I'll try to figure out how to find/save the .xdl file and upload that too. Thanks for helping.....I really appreciate it!
Your BLMs are swinging a little low... down to around 118. Something is causing a slightly rich condition. The thing is too is that I can only see the driver side since that side has the O2 sensor. If there's something else going on with specifically the passenger side on cylinders 2, 4, 6, or 8 (i.e., injectors, ignition wires, plugs, etc), the ECM won't react to it.
Would tweaking the timing back a few degrees change the rich condition? Does the timing affect the BLM? The log file does seem to show timing somewhat advanced.
The only thing I can think of that the O2 sensor could be picking up is an exhaust leak, but it’s most likely not that. The strong exhaust/gas smell makes me wonder though. There are no catalytics on it,so I was thinking that could be causing the smell.
I’ll go and take a picture of the injectors in a few minutes and post.
Without taking them out at the moment, this is what they look like. Not sure if you can tell anything from them, By the way, the tuner place that found the distributor issue checked fuel pressure and it was good, so at least that should mean he fuel pump is good.
Log file won't tell you anything about the timing that was set at the distributor. Only way to check that is to grab a timing light and check the timing.
No cats? Yeah, you'll get a strong exhaust smell from that...
Injectors look like factory multecs. Recommend you grab a multi-meter and measure the resistance across each injector (i.e., touch the probes to the terminals on the injector with the connector removed). See if you have any out of family... they should be around 13 to 15 ohms IIRC. You may have a faulty injector or something.
6 deg yeah. It can affect BLM, but probably in relation to how far off it is. if it's a couple of degrees off, then probably not much effect if at all...
Thinking about this a little more... that cam change is interesting.
Has the car ever run properly since the engine rebuild? Or has it been problematic ever since the engine rebuild?
Speed density cars are going to be pretty sensitive to significant engine changes like a cam. Depending on how different it is, it could be a significant part of (if not entirely responsible for) your symptoms.
On the xdl file, when you stop the data recording and the pop up window appears to save the file, simply take note of what directory TP is attempting to save it to. Then go back and navigate to that directory to grab the file and e-mail it out.
I definitely agree that a cam swap could have significant impact on driveability. The problem is I have zero way of knowing what the specs of the supposed new cam are. There is nothing spelled out on the receipt and the engine place has no record of the specifics......plus they farmed out the rebuild to another shop.....total mess. But instead of me getting all P.O'd again thinking about it, I just have to move forward with what I have and try to get it all fixed.
'Has it ever run properly'.......good question. When I first bought the car at 103K, it was in pretty good shape. The only reason I ended up playing with the engine is because there was a little bit of blue smoke, so time for new rings....and a rebuild. The engine was pulled from the car and rebuilt almost 2 years ago now . The car then immediately went to a paint/body shop and was redone. This took almost a year. So my first actual drive was about 6 months ago. From that point, I've had a lot of issues. First with it stalling while driving (that was supposedly due to a bad distributor....which took over a month to diagnose), then I had some front end work done. Then back to then engine place for what turned out to be a mis-installed distributor which lead to really bad engine bog since the timing was so far off.
Now I'm trying to nail down the last bit of the engine bog issue in the 2000 RPM range. This is why I'm data logging it in hopes of finding something that is still out of whack. Once I get home tonight, I'm going to make sure I'm set at 6 degrees BTDC and also make sure the PROM in the ECM is the correct one for the car (4307 ANJF / 4314 ANJA / 1350 AUJP). I'm also going to check the injector resistance like you mentioned in your previous post.
Data Logging - when I stop data logging and go to export/save the file, at the very top of the screen it shows the location and the file name ending with the .xdl extension. But at the bottom of the same screen, it only allows me to save a .csv or a .txt version. It makes zero sense to me. I'll keep playing with it and try to save/find a good .xdl file and post it (once I adjust all the stuff in the previous paragraph).
Last but not least.....lets say everything checks out okay, but the BLM is off, or something else in the data log file is off.......can I get a new PROM chip burned that corrects the issue(s)? At this point in time, I don't have near the knowledge I'd need to edit/burn my own PROM files, so I'd need to get one from someone.
From your description, it sounds like it’s never fully run “properly” after the rebuild. Your frame of reference appears to be the amount of time you drove it before the rebuild, in which case I’ll assume that you believe it was running properly during that pre-rebuild time. In which case, it sounds like the cam may be the issue. One clue may be the amount of manifold vacuum being observed at idle. I have some datalogs from other people with known factory-stock engines, so I’ll go back and compare your idle vacuum to theirs. If it’s significantly lower, that would tell me you have a little more radical cam than stock (although it may be still delivering a smooth stock-like idle… as even my cam with ~20° more duration @.050 delivers a very smooth idle, albeit with a lot less manifold vacuum). I think if your injectors check out, you’re getting adequate fuel pressure, and the ignition is all known good, then yeah, it may come down to a tune. There are several members on this board who do that kind of thing, so it shouldn’t be too bad.
Interesting about the cam. I wish I knew the specs on it. Big lesson learned......
Here is the latest info:
Tested all the injectors - all were between 16.2-16.3 ohms
MEMCAL is ANJF 4307 using the 7730 ECM - match a stock 1991 350 TPI
Timing was way advanced; I pulled it back to 8ish. I say 8ish because the Harbor Freight timing light with an advance setting is garbage. The line kept moving on the balancer, so I got as close as I could. Idle did seem to smooth out a little; no real change in driveability. One strange thing when I was setting the initial timing and disconnected the timing advance wire.....no SES light came on. I was under the assumption it would when I did that. Any insight?
I'll upload the .csv in a second. For some reason, when I go to upload the .xdl file into the 3rdgen forum, it disallows it. Any ideas on that one??
Hold off on checking the 091718.csv file I just loaded. For some reason it's the same data from yesterday. I just deleted all of the .csv and .xdl files from my computer and am going to go do another data log. Be back in about 10 min. Still have no clue why thirdgen won't let me upload the .xdl file.
One strange thing when I was setting the initial timing and disconnected the timing advance wire.....no SES light came on. I was under the assumption it would when I did that.
Either you unplugged the wrong connector. Or the ECM or ICM is bad.
I'll upload the .csv in a second. For some reason, when I go to upload the .xdl file into the 3rdgen forum, it disallows it. Any ideas on that one??
Zip the file first then upload it. Only certain file name extensions are allowed.
OK.....and I apologize for loading up crap files prior to this. I wasn't saving the latest info and the data was all old. The attached .csv file is the LATEST and has the timing adjusted per my previous post. I will email the .xdl file once I post this.
BLM seems high; Manifold pressure at idle is in the low 40's; timing adv is in the high teens at idle and goes all the way into the upper 30's with more RPM. Driveability is ok, but nothing stellar. Doesn't seem to have a lot of punch since I changed the timing.
When you get a few minutes, have a look and let me know what you think. If I do in fact have a non-stock cam and I need a revised tune, can you (or someone on this forum) burn me a new chip that will get this thing running good?
RBob.....the ECM is new/rebuilt. When I start the engine, the SES goes through its start up flashing routine, then turns off. I can jumper the ALDL port (A and B if I remember correctly) and get the code 12 telling me the ECM is communicating. The timing adv wire I disconnected is the single light brown one coming off the coil, so I believe that is correct. Maybe I'm missing something?
ULTM8Z.....I emailed you both the .csv and the .xdl file. Once I figure out how to zip the .csv file, I'll upload it here. If anyone wants to help this pitiful soul out, let me know and I'll email you the files also.
Assuming I need a tune, who out there in the Thirdgen nation can help me out? Obviously I'll pay for it.....I just want it to be done by someone that really knows what they are doing and can use my datalog to adjust things accordingly.
Here's what your BLM's look like (the first picture)... Your fuel trim is pretty lean... which seems like it would stand to reason if your cam is a little more radical (demanding more fuel for the extra air). You're not necessarily running lean in closed loop since the ECM is able to richen up the mixture (you don't run out of adjustment until the BLMs hit 160).
However, you're probably going to end up lean on your accelerator enrichment, which could explain some of the bogging (ECM does not adjust AE like it does closed loop fuel... you only get what's programmed in).
Also, when you go into power enrich (PE), the ECM is going to significantly increase the commanded AFR because it's having to trim the fuel like this in closed loop. This is going to make GM's already overly-rich PE AFR even richer (it's a safety protocol that GM put in to avoid overly lean high-load conditions that could damage the engine). Granted the cam probably wants some more fuel than the stock cam, but again, GM was already too rich to begin with...
The only odd thing I noticed was that toward the beginning of the run, I was seeing rich BLMs. The second BLM histogram is more indicative of the early part of the run... it was a little richer, but still mostly lean. So it's getting leaner over time as the operating temperature increase (which stands to reason to some extent).
Again, this is all assuming that everything else about the car is in good working order... fuel pressure, injectors, ignition system, sensors, etc...
RBob.....the ECM is new/rebuilt. When I start the engine, the SES goes through its start up flashing routine, then turns off. I can jumper the ALDL port (A and B if I remember correctly) and get the code 12 telling me the ECM is communicating. The timing adv wire I disconnected is the single light brown one coming off the coil, so I believe that is correct. Maybe I'm missing something?
Unless you reset the ECM, code 42 should also have flashed. The EST/BYPASS connector is over by the HVAC box on the passenger side. Single wire, tan with black stripe. Exits the harness, connector is there, then back into the harness. SES will turn on and code 42 will be set with the engine running.
ULTM8Z.....thanks for taking the time to analyze my data.
Grasping at my limited tuning knowledge, don't I want my BLM and INT numbers to both be hovering around 128? Given that mine swing around quite a bit, I'm not sure if it is good or not.
I've tried graphing the data out using Timing Adv, INT, BLM, Manifold Pressure, and O2 voltage trying to get a correlation, but I'm not having a lot of luck. Looking at the various number, what needs to be corrected with a tune? I've included a chart showing the five parameters graphed out for about 4.5 min.
I’ll take a look at the spreadsheet when I get home…
Yes, you want to be at or below 128 everywhere for reasons I mentioned earlier. Ideally, in a situation like this you’d want to get a WB O2 sensor so you can see what’s going on in the non-closed loop operation.. i.e., Open Loop, Power Enrichment, Accelerator Enrichment.
Given you have what appears to be a different cam, it’s a bit of a wild card now. Absent a WB O2, it’d be pretty much tuning blind. For example, when someone changes to Bosch-III injectors and their BLM’s go nuts (but everything else is stock), then getting back to 128 BLM’s ensures that everything else in the tune is going to be correct.
But since your cam appears to be different, we don’t have that stock baseline to fall back on such that attaining 128 BLM’s in closed loop automatically means the non-closed loop stuff is back to normal. But given where you are, again assuming everything we’re seeing is related to this supposed cam change… then to the first order, you’d have alter your VE table to increase the values.
Given your BLMs are into the 140-150 range, we’re talking about roughly 10-15% increases (140/128 = ~1.10). Once that’s done, (absent a WB O2 sensor) you can start evaluating how the car “feels” everywhere else… i.e., WOT, open loop during start up, throttle transitions, etc… Possibly make some “guessing” adjustments to see if driveability issues clear up (but take it from me, trying to do that without a WB is pretty much a fool’s errand).
I could purchase a WB O2 sensor, but installing it and getting the ECM to read it are out of my comfort zone, so I'd have to find someplace to install it for me. Think it would be something costly to install? Looking at 'Innovate Motorsports 3918 MTX Series MTX-L Plus Wideband Gauge with o2 Sensor', the parts would be around $160.
If I didn't get a WB installed, how difficult would it be to do a tune based on the data log info I currently can store?
One thing I'm going to do is check for any type of exhaust leak that could be throwing off the O2 sensor. Given the fumes I smell, potential is there for something being loose/worn. But given the car doesn't have catalytics, I guess some smell is normal.
Adding in a WB isn’t terribly difficult, but it does take some work… You have to change over to the S_AUJP calibration in your tune. To get TP to see it, you’d have to wire it into the ECM. There are instructions in various threads on how to do that. Then just need to get all the S_AUJP files for TP. The files are all also available on this site. Again, not overly difficult, but it’s not trivial either… but once TP is logging WB data, then you can shoot directly for ~12.5:1 by playing with the PE tables, and pretty much know you’re getting that via the TP data. To get any more optimized than that would require a chassis dyno. I tuned my car via “butt dyno” and the WB O2 and I’m very satisfied with the results. Tuning w/o a WB is also not impossible… You’re not that far off from factory IMO, so in the end you may be able to get close enough. It all depends on what you’ll be satisfied with. If it runs decent, most people would be satisfied.
Here's the link to what got me going on the WB setup... it'll give you an idea of the level of complexity... For me, (as you'll see in the thread) the software setup was a lot more difficult than the hardware.... lol...
My eyes began to cross pretty quickly reading your struggles to get the hardware and then the software working for your WB O2. This just solidifies that I'd have to have a 'pro' install one for me and get it working. 'HOPEFULLY' a solution can be worked out for me using what I already have.
Yeah if it wasn't for the brainiacs and wizards on this board like RBob, JP86, 84Elky, and the others like them who are willing to volunteer so much of their time for the rest of us, this hobby would be 100% impossible for me.
Unless you reset the ECM, code 42 should also have flashed. The EST/BYPASS connector is over by the HVAC box on the passenger side. Single wire, tan with black stripe. Exits the harness, connector is there, then back into the harness. SES will turn on and code 42 will be set with the engine running.
The EST is most definitely disconnected when I'm setting the timing. The ECM has already been replaced. Given it gives me a code 12 via the SES when I do the paperclip jumper, I know it communicating, so the ECM should be ok. Am I missing something?
Agree I should be throwing a code when the EST is disconnected.....but I didn't. Given I get a code 12, the ECM is communicating. If the ECM were bad, it shouldn't give me even a code 12, right? I may be wrong....not the first time, and not the last. Just curious how it's not showing a 42????
09-16-2018, 10:47 AM
