Rocket-Doc

iTrader: (11)

New motor: 355ci, LT4 Hotcam, 279/287; duration at .050, .525/.525 lift. 113 Heads. Airgap intake.

With that said I set initial SA to 8*. The motor started right up, when it warmed up I pulled a little over a minute on the attached datalog. I'm sitting at 128 INT and BLM all day. So that is good.


When we were throttling it, (not WOT) mind you. We were getting pops, this I'm guessing is because there is no AE, or not enough of it. I found some post with RBob stating that the 454TBI and long runners intensifies the need for AE.

So steps for next Saturday are 1. Reset for 12* base, because of heads and cam, 2. Complete IAC adjustment, 3. add in 10%AE, on TPS table? 4. start doing VE learns.

89-S-dime

iTrader: (3)

nice!

RBob

iTrader: (1)

The 3001 BIN is set for open loop via the forced open loop flags:

Option Word 1 - Bit 3 - OpCrs
Option Word 1 - Bit 2 - OpIdl
Option Word 3 - Bit 5 - OpDcl

This is why the INT & BLM sit at 128. Note that it is common for open loop decel to be set. This prevents surging due to proportional gains.

Trying clearing the open idle and open cruise flags and see how it is.

RBob.

Rocket-Doc

iTrader: (11)

Well **** RBob, that changes things. So step one unflag the two options. Then check the INT and BLM again, and adjust pressure to get the INT and BLM as close to 128 as possible?

Then start the tuning?

RBob

iTrader: (1)

I would set the fuel pressure to the level required to support the flywheel HP the engine is expected to make. If the heads are un-ported say 355 HP?

With 80 #/hr BBC injectors and 20 psi fuel pressure, that will support about 375 HP.

Then adjust the "BPC - BPC vs VAC" table for the displacement and injector flow (EBL_Utility). Flash it in and see how it runs.

RBob.

Rocket-Doc

iTrader: (11)

Well, I was hoping for a bit more than that. The heards are off of a ZZ4 which puts out 355 stock, at 10.1, I'm up at 10.6 and have a larger cam, but yes I see your process.

RBob,
we kindsa figured out the fuel numbers already per this post this post

Rocket-Doc

iTrader: (11)

So dumb question here, does it matter if the EST bypass is connected/disconnected while doing the IAC reset?

RBob

iTrader: (1)

No need to do an IAC reset with the EBL series of ECMs. The ECM resets the IAC at key-off following an engine run. The TPS setting auto-zero's.

So, as long as the TPS voltage is between .4 and .8 volts you are good to go (spread is actually wider, but this is a good range).

Then for the IAC steps, on a warm engine with no other loads. Adjust the throttle stop screw to get 5 to 10 IAC steps. Can use the WUD for the step count.

Also, if you need to open the throttle to get this count, the ECM can drop out of idle mode. It thinks the driver is on the go-pedal. Can use the Idle indicator on the WUD to see if this occurs.

If it does, key-off for ten seconds, restart the engine, let idle for about a minute and continue on.

RBob.

Fast355

iTrader: (2)

With those heads, cam and intake you need more like 380-400 hp worth of fuel depending on the headers and exhaust.

Rocket-Doc

iTrader: (11)

RBob, ok will do, I should have more answers on Saturday evening.

Fast355, that sounds a little better, thanks for chimming in...

Rocket-Doc

iTrader: (11)

@Fast355 a,d RBob, Is it unreasonable to think that I could get this thing to idle at 650? The IAC - Idle speed is set at 850 @ operating temp. I want it to be lower, is something like this to drastic?

Fast355

iTrader: (2)

I have a Lunati version of the same cam in my Express van. Even with the newer LS based PCM I idle around 750-800 rpm. My idle is set at 850 in park/neutral, 800 in drive with the a/c on and 750 in drive a/c off.

Rocket-Doc

iTrader: (11)

@Fast355 and RBob, so I went to the shop today. I tried doing a VE learn but it kept popping on slow acceleration. Quick throttle snaps proved to not have any issues. Datalog shows that quick throttle snaps had no fueling issue, but slow accelerations proved to be lean. I checked the fuel pressure it is 25# at idle and jumps up when throttle is actuated, so fuel delivery doesn't appear to be an issue.

The datalog consists of:
idle
slow ramp (popping)
slow ramp (popping)
quick snap (no popping)
quick snap (no popping)
quick snap (no popping)

I did figure out one issue at the end. I added a throttle return spring as throttle wasn't not consistently returning. I need to recheck my IAC steps when I go back tomorrow.

RBob

iTrader: (1)

The popping is caused by the AFR being too lean. I would add to the VE table is those areas followed by VE leans. Note that the vehicle needs to be driven for good learns.

Also, on the throttle snaps to 4100 RPM, there was up to 10* of spark retard.

RBob.

bluers91

I have the same cam with Vortec heads and a 454 TBI. It idles great at 650.

I'm also running a 28 psi spring.

Rocket-Doc

iTrader: (11)

I have to give it to the guys that figured out how to tune .bin files, because this stuff is getting the better of me. After having to buy a new bottom end, I'm so dam paranoid it's driving me nuts.

So I started by multiplying my AE tables by 1.1, saved ran a VE learn, saw a bunch of negative numbers on the change screen. I did this 3 times. Each time the popping just kept occurring, not seeming to get any better. The dam thing is still running lean at idle. So I increased the fuel PSI by 1 to 26, re-calibrated the BPC vs VAC table, and Single injector flow and reloaded. Still popping. The .bin file is the current one I'm running and the data logging is from me TRYING to drive, I gotta say the popping has me terrified, can't afford another motor.

That's great new something to shoot for if I ever get this thing drive-able.

bluers91

TBH I wouldn't mess with the AE just yet. I'd reset it back to defaults for now. I never did and my setup is running pretty decent at this point from only VE Learns and some SA timing table tweaks. I know there is more power in it but AE gets a little more complicated.

I would try the following:

Let the car warm up for a bit at idle. I noticed your CTS is not even above 94 degrees so its still rather cold. When my car is cold it doesn't run nearly as good. Warm it up to proper operating temp first then begin messing with the tune. Get it up over 160F and see how it runs.

After its well warmed up begin a datalog and start a VE Learn. If you notice it having a hard time running at idle watch the VE screen and note the cells where its stumbling. I had to increase a few of those cells manually at first in order to get it to idle well. The area between 600 - 1000 rpms and between 40 - 50 KPA map values. Watch it in real time then open the bin in TunerPro and increase the VE in those cells manually. Save it and re-flash the ECM then proceed with more VE Learns. I also noted that sometimes when I would increase those cells to get it to idle better a VE learn would override my numbers. I also switched to the Open loop idle at one point.

I'd also keep an eye on the Spark knock screen after its warmed up. Maybe its a little too advanced. You are running a full point more compression than I am. If you're getting a lot of knock counts your timing may be a little too hot. I like what I heard from Fast355 once. Start with fueling and keep your timing conservative at first. You can advance it more after fueling is worked out.

I had to go back and re-read RBOB's instructions a few times to get the basics stuck in my head. It all came down to warming it up, doing the VE Learns and making a few manual tweaks in the BIN. It took many VE Learns to get it working good enough to feel okay driving it around. If you see a lot of corrections just re-flash the ECM and start a new learn. Eventually things will begin to smooth out. I was in your shoes just a few months ago and now my car is running really good.

Rocket-Doc

iTrader: (11)

Blue, my temps were reading in C, I changed it over to F. for this new read.

Fast355 I changed the VE tables per your suggestions, now I'm running rich... Here it starts shaking and popping when I'm at 30+ degrees. So I pulled some timing out.

I'm starting to think carb at this point. This such a pain, when I don't completely understand it. Any help is much appreciated.

Fast355

iTrader: (2)

When you say popping is it out of the intake or exhaust? Also I would run through the basics just to make sure you have not missed anything. It is super common to mix up the plug wires at cylinder 5 and 7. A rocker arm that is adjusted too tight can also cause the engine to pop. An EFI engine will run way better than a carb will once it is dialed in.

Just FYI in my Express van I have places in my tune that run close to 50° of timing advance because that is what the engine likes at that RPM and load. That particular area is an overun area going downhill at speed, but fact remains it enjoyed the extra timing. Your WOT timing should not run much over 32-34° with those heads.

Fast355

iTrader: (2)

I warmed up the Express van driving it to pickup food and made a few video clips. This is a stock L31 4-bolt main bottem end with a set of ported 906s with 2.02/1.60s that have been milled a bit sitting on .016" rubber embossed steel shims for ~0.041" quench distance. Compression ratio is at about 9.8:1. Has the Lunati Bare Bones Hotcam in it. 276/286 advertised, 218/228 @ .050, .536/.536" with my 1.6 roller rockers, on a 112 LSA. The cam is installed 4° advance over the 108° ICL machined into the cam for a 104° ICL. Running a ported MPI marine intake manifold with Trailblazer SS 32 lb/hr injectors. EFI connection 24x coil per cylinder kit with 5.3 coils. Tune is based on a modified 2001 8.1 Van tune with alot of the 5.7 tables copied into it to get it running and tuned from there. It runs the 8.1 drive by wire throttle body setup. Thorley Tri-Y headers and dual 3" exhaust to the muffler through 3" Thunderbolt cats. 3.5" tailpipe. Idle speed in this video is about 850 rpm in Park with the A/C on. This setup LOVES AE and timing to get good throttle response on the low end and a clean idle. It hates idling under 750 rpm with the misfire monitoring on OBD2. Have to idle it higher to keep it from throwing a P0300 which would keep me from passing inspection. I could desensitize the misfire detection but it seems that when I do the readiness monitor never changes to Ready which is also a failure because many other tests will not run. With the 2,600 stall it really does not have much creep anyway even idling higher and my A/C stays colder with the mechanical fan and compressor turning faster anyway. Throttle response is also noticeably better at 800 rpm than 650-700. With the 2,600 stall in the 4L85E and the 4.56 posi out back I find myself often having to watch my right foot out of lights and stop signs, especially on RH turns. I have actually unintentionally drifted a 6,200 lbs Express van a few times. In fact it cuts a better 60' time than my 450 HP M56 Infiniti does at the track, I wish it had the response this old 350 does and I will say it is tuned too but there are many torque management settings not defined in the M56s ECU and TCU that keep it somewhat tame off the line on a quick throttle stab. In the video the throttle revlimiter kicks in at 6,000 and fuel shut-off is 6,200. It free revs so quickly it hit injector fuel kill several times.