94_LT1_TransAm

No lol what I mean is, I can look at the data my pcm is telling Scan9495 it just wont record it for some odd reason. I can stare at it all day long but when I go to save what I was seeing from the pcm, it wont lol idk why. I will look into it tonight and see what I can do. Also, when you told me to also include my tune off of the pcm, how do I do that? The PCM was flashed by the dealership with a factory default tune from them, not me. So how do I copy the file from the pcm to my laptop?

hrcslam

Are you running Scan9495 in compatibility mode for Windows XP SP2?

I'll have to look at the EE Hack program to see how to pull the tune.

What year is your car? A4? I might have a stock tune saved.

94_LT1_TransAm

1994 trans am a4. I got it to work finally. I'll post the datalog as soon as I can.

hrcslam

Do you have the performance mode button? Also, what gears do you have? I have a stock tune for a 1995 Camaro A4.

94_LT1_TransAm

Ok here is my log from tonight. Its about a 10-15 minute drive. Yes I have the performance transmission button, and I have 3.42 gears. I hope this helps you guys better understand whats going on here lol

hrcslam

Looked over the data log. The Target Idle RPM is 550 or 600 (this depends on if you're in gear or not, higher when in gear). Being A4, those Idle targets seem normal to me. So the idle RPM is close to the target according to your datalogs (your Tach gauge may be off, it's common, but usually off high not low).

But, the IAC is closing too much and you have a BLM split (this means you have uneven fuel distribution in relation to air distribution, and since you have multiport injection it's usually an air flow problem). This is usually an indication of improperly adjusted Throttle Blades, meaning they are cracked open a little bit when you are off the throttle. This allows air to flow through the throttle body instead of the IAC, forcing the IAC to close to lower the RPM. Because of the location of our TB's, idle air doesn't flow evenly in the plenum to each cylinder and this will usually cause a split BLM (this is very common on ported and aftermarket TB's, and with engines with big cams even on the stock TB).

You are running rich in the BLM cells below 1200 RPM. Two things can be attributed to this, your headers (although they are shorty so not really) and the CAI Ram Air mod. The MAF is calibrated to it's position, location and the ducting it's mounted in (it could care less what engine is behind it for the most part). You moved it, a lot. So it's calibration is likely off. But, do make sure you don't have any exhaust leaks (they will cause a false lean reading giving you an actual rich condition).

So if you don't have exhaust leaks before or near the O2's, try this:
Disconnect the MAF and readjust the TB Blades (you want them completely closed, but not closed enough to where it sticks shut). With the MAF disconnected (assuming all the mods in your signature are accurate and up to date), do another data log (if you know how, wipe the BLM memory before you do the data log) and post it up. You will get a check engine light, just confirm it's for the MAF with the data logger. Disconnecting the MAF forces SD (Speed Density) mode, this forces the engine to fuel based on RPM, MAP, and IAT and no MAF. If the BLM's in your datalog return to stock like (hovering around 128 LT BLMs), the MAF is out of Calibration, tuning this in isn't all that hard either. But we'll get to that if it needs it.

About your earlier questions, to pull the tune from your PCM (ECM) using EE Hack, with the program running and hooked up, and the engine off (key on), click on the "Flash" button (the one with the Exclamation point in a Triangle). It'll open a new window, at the bottom of the new window it says "Download BIN from ECM", click that and follow the program from there. A BIN (or .bin) is the file type the tune is saved in.

You said you have Tuner Pro RT right? Did you download the EEX Definition File from Steveo's web site (where you got EE Hack from)? It's an XDF (or .xdf) file. Makes tuning our LT1's in Tuner Pro way easier and easily puts TunerCats to shame. If you want to raise the idle, you can easily with EE Hack and Tuner Pro RT.

But first, I'd look at getting the TB blades looked at and make sure it's the MAF calibration that's causing your rich low RPM condition. Then work on tuning.

94_LT1_TransAm

Ok so you want me to lower my set screw on the throttle body a little bit and set my tps sensor to .49 volts to match, plus run a datalog in speed density mode after i set my throttle blades correct? Also, how do I wipe my BLM memory? BTW, my top end is all stock except for a brand new factory bought MAF and TPS.

hrcslam

You shouldn't have to adjust the TPS, it should do it on its own, or there's a simple reset procedure for it. It gotta look it up again though.

Yes run speed density to troubleshoot the MAF.

You don't have to wipe the BLM memory, the car will adjust all on its own, but it'll take longer to get good data to log. In EE Hack, click on the "Control" button. In the new window you'll see a "Reset BLM" button in the top left hand portion of the window (it's in the Gray boxed area labeled "Fuel"). Select that.

The Ram Air mod and the headers will change the VE of the engine a little bit (so SD mode might be off slightly, but not as much as it is now). The Ram Air won't effect anything until the car is at speed. The headers should have a very small effect at low RPM, but start to show at higher RPM. The Calibration of the MAF will change when you change it's location, position, or the tubes before and after it that effect how the air is flowing trough it.

hrcslam

Here's the re-learn procedure for the TPS.

Key off.
Unplug TPS.
Turn key on for 5 seconds.
Key off.
Plug in TPS.
Turn key on. Closed throttle should be 0%.

94_LT1_TransAm

I was just reading that same post lol. lower set screw and run speed density after blm memory wipe, I will get a datalog of that tonight sometime and repost!

94_LT1_TransAm

Ok, here is my log from town tonight in speed density mode. The set screw was adjusted down so now the IAC counts are better at idle but not exact to 30 or so counts (just a tad bit lower from a quick glance at idle). I reset the BLM memory and even downloaded the .bin from my PCM to my laptop if you would like that also hrcslam. Let me know what you think! Thanks

hrcslam

That looks better and is about what you should expect to see between the CAI Ram Air and Headers (you're lean). How does it drive? Idle? Better?

It seems to be running lean a bit in the lower RPM range, under 2K and below 75kPa. That means the mods you did to your car made it more volumetrically efficient and it want's more fuel to match the additional air.

What I would do from here, is log with EE Hack and use the "Analyze" button to see what changes need to be made to the VE tables. But, you don't have too adjust the VE tables, they are in range. It's recommended though. If you do decide to change the VE tables, read up on this site to get an idea of what needs to happen. I'd shoot for getting the BLM's between 123 and 133. Remeber you're looking at the LT BLM's, not the ST BLM's. After you get the BLM's close (or where you are comfortable with them). Then adjust the MAF Calibration Tables after you connect the MAF. It'll be the same process as the VE tables; use the BLMs to figure out how much to adjust the table and adjust until it's close enough for what you think and how the car behaves. With the MAF connected you shouldn't touch the VE tables and without the MAF connected, don't touch the MAF tables. I usually take what the BLM reading is in my datalog and put that over 128 like a fraction. The result will be how much you multiply the BLM Cell by. If this is confusing, it's o.k, read that link.... a lot. So 137/128=1.07. Lets say BLM Cell #10 is reading 137 LTBLM's, I'd select all the VE cells between 1200 and 2000 RPM and 50 to 80 kPa (BLM Cell 10) and multiply that by 1.07. Or if it was running LTBLM's of 122, then it'd be 122/128=0.953, so I'd multiply those cells by 0.953.

You still have a slight (albeit better) BLM split (the left bank and the right bank LTBLM's don't match, they should). When you adjusted the TB blade stop screw, did you physically look at the blades to make sure they were all the way closed?

The IAC counts look great. If you want the Idle RPM to come up, adjust that in the tune.

Also, if you could post up your current tune, I'd like to have it. I'm starting a personal collection and having an A4 T/A with the performance button on hand would be helpful to others in the future. Thanks!

94_LT1_TransAm

Ok that's all too confusing for me lol, I'm not sure I want to mess with all that and accidentally screw up my pcm by messing with it to much, that's why the other pcm was bad due to the fact previous owners tried tuning the pcm too much lol. I don't even know what im even looking at when those tables are up. Btw I have Bosch O2 sensors... would that affect my BLM readings since I've read these O2's can be bad for LT1's?

hrcslam

I forget what brands do or don't work well with the LT1's. But, I can look at logs and numbers all day long, those need to be compared to how it actually drives and runs. So how does it run and drive with the TB adjusted and MAF unplugged? Is it better?

If you post up your BIN and a longer data log, I can adjust the tune for you.

94_LT1_TransAm

It does feel a little better (could be my mind playing tricks lol) and smoother on acceleration but idk if it performs better from a stop or not cause its been rainy all week lol, usually my car bogs and backfires through the intake every now and then when I go to stomp on the gas unlike my brothers 95 LT1, his revs up sooooo much faster than mine and runs waaaay better too lol ill post my .bin tonight if you are willing to help sort this out for me, I appreciate all the help cause I cant find anyone else on my end that knows anything about tuning... btw if you adjust the .bin say 2 or 3 times before its perfect, will my pcm still work properly or will it zap the life out of the pcm like the previous owners did during tuning?

hrcslam

I've loaded well over 50 tunes into my car. No issues. Usually a PCM failure due to tuning is done because of another error, laptop dying while loading or unplugging the cable while loading, or the car dies or voltage drops too low while loading/pulling tunes, etc. The PCM is solid state flash drive. So can your thumb drive fail from too much loading and unloading? Not really, usually it's caused by something else.

I have no issues helping you sort this out. Your car should be running better right now.

It should be noted, that you must make sure the engine is mechanically sound before adjusting the tune. Did you do a compression check? New plugs and wires with the Opti? None of the spark plug wires are touching anything that could cause arcing, this includes the wire from the coil to the Opti (I've experienced a stumble under low RPM high load from that wire arcing (very slightly) to the water pump, I've also had a cracked psark plug cause some stumbling too)?

Back firing in the intake can be caused by either open valves (bad valve adjustment) or poor spark timing (bad cap and rotor or opti). A rich condition (like you had) can cause popping in the exhaust, but you really weren't that rich to have those types of issues. A little popping here and there, but not backfiring through the intake. What you need for back firing into the intake is fuel, air, and spark. And since the spark is introduced when the intake valve is supposed to be closed, it's shouldn't be happening in the intake manifold. If the spark timing is off and is sparking with a valve open, you'll get it. Or if the valve isn't closing all the way you'll get it.

It has been experienced that some "new" Opti's are pressed together wrong. So the drive side of the Opti (that mates up to the Cam) and the rotor side are not pressed together correctly. This will throw your timing off and can cause your issues. However, I haven't heard of an AC Delco or Delphi unit do this, nor an MSD. It's only happened on a few of the cheap brands. I'd do a compression check though, to rule out mechanical issues. you could also try EE Hack Cylinder Balance test under the "Tests" button. Or you could cut a cylinder at a time with EE Hack under the "Control" button and see if one makes a difference less than the others.

Did your car do any of the back firing during the datalogs you posted?

94_LT1_TransAm

No because it usually only backfires through the intake when I either stomp on the throttle during a dead stop or while rolling down the road, but its only intermittent... Now it does do the usual LT1 pop and bang when I roll off the throttle to slow down every now and then or get back on the gas after a long downhill coast.

hrcslam

Looking at your data logs, I doubt that's something you can tune out (although you could use a tune). I'd do the cylinder cut check in EE Hack and see what results you get. I'd actually do a compression check over anything else, and if you are replacing spark plugs and wires, you are already there (it's still a pain in the *** though). Using EE Hack Cylinder Cut test can tell you if you need to do a compression check though. If you cut one cylinder at a time, you should hear a difference in idle. If you cut one and there is no difference or the difference is bigger than the rest, check that cylinder for compression and or valve adjustment and spark plugs/wires. Also, if you confirmed the TB Blades are completely closed, and you are still getting split BLMs that would point to a plugged or open injector or bad spark on one cylinder.

94_LT1_TransAm

Ok, I did the cylinder power balance last night and I did notice changes in idle one by one that were near the same idle change. So I will post some datalogs tonight that are longer for you to look at with the stock .BIN file. Thanks once again for helping me!

94_LT1_TransAm

Ok so here is my logs from tonight, one is in speed density mode and one with the MAF plugged in. I did notice a difference in acceleration a little bit. With the MAF plugged in I noticed that under quick throttle punches that I could here it backfire a little but not in Speed Density mode. Also included with the logs is my .bin straight from the pcm. I copied the file for a test in tunerpro but I didnt know how to view it lol, also I routed my plug wires and zip tied them away from the headers and even wire loomed them, even the coil wire. My opti is a brand new AC Delco unit with new plug wires.