Idle Issues, Beginner Tuner

[JordanSBC427]

Hello,

Looking to get some help with regards to Idle issues. My father and I have put together a SBC 427, and had a basic tune dumped into it from a camaro so we could run it on the dyno. The small idle issue we have is that it will not start just by turning the key, I have to press down on the peddle to get it to fire. Once it starts, it idles reasonably well and usually around 550 rpm. We are running an LS1 ECM from EFI connection, and an aftermarket TPI from FIRST fuel injection. Not sure if the Idle air motor can't provide enough airflow for the tune or if we have to much fuel being dumped in during cranking. I have downloaded my tune on my laptop and looked around a bit but as of now, its all greek to me as i'm very new to this. Does anyone know of any quick things to test or checks that could help eliminate some possibilities?


Thank you,

Jordan

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[JordanSBC427]

Anyone?

[joecar]

Hi Jordan, welcome to the forum, sorry I somehow missed this thread.


Have the VE and MAF tables been corrected...? If so, by what method (details) and after correction did you log the fueling error (aka BEN)...?

Log IAC steps to see what the IAC is doing... if the PCM can't open the IAC sufficiently you will see IAC pegging at max steps (130).

Post your tune file and any log files here in this thread.

[joecar]

So you're using a 0411 PCM to run a TPI system with harness/sensors suitable for the PCM...?

[joecar]

Also, for general tuning, see posts #4 and #29 here: Summary-Notes (http://forum.efilive.com/showthread.php?14188-Summary-Notes)

[JordanSBC427]

Thank you, and no problem.

Are you asking if the tables have been corrected since the dyno? I have yet to log anything or change any settings after the dyno. The guy that did the dyno had his own tuner dump in the tune and set everything up for this engine. Now It is in my garage and I am trying to learn as much as I can about the tuning end of things and make it run as best as possible. I can only do some idle data logging at the moment as it is winter at the moment. Whats the easiest way to post/attach a tune file. The formats I try attaching are not acceptable....sorry.

Thanks.

[JordanSBC427]

So you're using a 0411 PCM to run a TPI system with harness/sensors suitable for the PCM...?

Yes I believe that sounds correct, not 100% sure on the 0411... I see;

OS: 12212156
Calibration: 12209171

under "calibration" of my efi live program.

But I believe it is out of a 2001-02 Yukon

[darcy]

The formats I try attaching are not acceptable....sorry.

You should be able to upload and attach a tun or ctz file without issue

[joecar]

At the bottom of the reply pane click Go Advanced and then click Manage Attachments...

[joecar]

Can you get your tuner to send you the final OBD2 log from the dyno (the one he did to verify his tuning)...?

[JordanSBC427]

16278

Let me know if I did this correctly.

This should be my tune.

Thanks.

[joecar]

I'm looking thru your .tun file...

[joecar]

Out of Range parameters/tables:


Engine Calibration.Fuel.DFCO
{B3308} DFCO M6 Enable Temp, was out of range when loaded.

Engine Calibration.Fuel.Mixture
{B3614} Hot PE Mode Coolant Temp Threshold, was out of range when loaded.

Engine Calibration.Fuel.Lean Cruise
{B3636} Vehicle Speed Lean Cruise Enable, was out of range when loaded.

Engine Calibration.Fuel.Trim
{B3803} Maximum Coolant Temp to Enable LTFT, was out of range when loaded.

Engine Calibration.Abuse Management
{B1207} Abuse Management Vehicle Speed Threshold, was out of range when loaded.

Engine Calibration.Torque Limiting
{B6615} Max Torque, Front Axle, was out of range when loaded.
{B6616} Max Torque, Rear Axle, was out of range when loaded.
{B6617} Max Torque, Front Prop Shaft, was out of range when loaded.
{B6618} Max Torque, Rear Prop Shaft, was out of range when

Set those to in-range values (set them to max-1).

[JordanSBC427]

Hey Joe,

Thanks for the helpful hints on the out of range parameters. I changed all the parameters that were at 140 to 139 (max minus 1) but there were a few that were set at 0, so I went min plus 1. Is that alright or did you want all the parameters at max minus 1?

Jordan.

[joecar]

Hi Jordan,

The tuntool has a quirk regarding OOR cells...

have a read of this post: help-kr*-problem&post=14 (http://forum.efilive.com/showthread.php?9931-help-kr*-problem&p=87052#post87052)

[JordanSBC427]

I have cleared up those OOR parameters and that is looking good. I have attempted to do a little logging while doing some engine cranks, I adjusted a few parameters and downloaded them into the ECU and tried some cranks after each change I downloaded.

I attempted to adjust that Start Up Friction Air Controller multiplying ECT Cells 8, 20, 32 by 20% and didn't sound any better.

I also attempted shifting the IAC Effective Area Cells up 7 rows then down 7 rows. Also didn't notice much of a difference.

I tried to lean out the commanded fuel when cranking table a tad to see if that would make a difference and no big changes.

Then my battery was beginning to get low and noticed program was trying to establish connection to ECU, so I had to stop and will be charging up the battery to full voltage again.

Another question about the WB02 Sensor. Does this require adding another bung in my exhaust system for mounting this sensor?

Thanks,

Jordan.

[joecar]

Yes, please avoid flashing when vehicle battery or laptop battery are not fully charged.

[joecar]

Depends on wideband... for example, LC-1, LC-2, LM-1, LM-2 from Innovate provide a narrowband signal output for purpose of driving the PCM's NBO2 inputs.

[JordanSBC427]

Hey Joe,

I have a quick question about Injector Flow Rate Calcs. I have been reading a bit about IFR's and ran some numbers as well as punched them into the excel spreadsheets that calulate it for you, and i'm getting a fairly big difference in g/sec than whats in my tune. I don't have my tune in front of me at the moment but at 0 kPa Vacuum i remember it started out at 4.500 g/sec and increased. After doing the calculations I keep getting around 6.36 g/sec at 0 kPa vacuum. Just wanted to run this by someone. 60 lbs on FPR (not a vacuum referenced gauge) 42 lb/hr at 43.5 psi.

MANVAC(kPa) 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80
Injector Flow (g/sec) 6.363 6.401 6.440 6.477 6.515 6.553 6.590 6.627 6.664 6.700 6.737 6.773 6.809 6.845 6.880 6.916 6.951

How many problems does it create having the wrong IFR's programmed in? Could this be another issue as for why I need to step on the pedal for a start?

Thanks.

[joecar]

If your VE and/or MAF tables are already corrected, then they have the IFR scaling "baked" into them...

( i.e. when IFR is shifted by X %, VE and MAF tables are also shifted by same % (in the same direction) )


BTW, my math comes out like this (rounded to 1 decimal place):

At 43.5 psi: flowrate = 42 lb/hr = 42 * 0.126 = 5.3 g/s
At 60 psi: flowrate = 5.3 * sqrt(60/43.5) = 6.2 g/s

At VAC = 0 kPa: IFR = 6.2 g/s
At VAC = 80 kPa: IRF = 6.2 * sqrt(480/400) = 6.8 g/s

( and spreadsheet verifies this )

[joecar]

If you have to step on throttle to start engine, then it sounds like the startup friction tables and/or idle desired airflow are not correct.

[JordanSBC427]

Ok, so by changing by IFR's it will automatically change my VE tables to match the new flow rates?

Thanks for checking my calcs Joe.

When adjusting my startup friction/desired air flow....should I just be slowing increasing by say 10 or 20% incriments or is there a way to figure out where it should roughly be sitting?

[joecar]

Ok, so by changing by IFR's it will automatically change my VE tables to match the new flow rates?
No (not automatically)... your VE and MAF tables were tuned with that IFR, so changing the IFR will now make VE/MAF tables be off by the same percent that the IFR is changed.


When adjusting my startup friction/desired air flow....should I just be slowing increasing by say 10 or 20% incriments or is there a way to figure out where it should roughly be sitting?
I'm not sure (I don't have to do very much idle/startup tuning)... try in both directions and observe the result (you will see which direction is the right one).



( there are only a few threads on VE/MAF tuning... and there are a whole bunch of idle tuning threads... the reason being that idling tuning is much more involved )

[JordanSBC427]

Ok Joe, thanks for the clarification. So by changing my IFR I will have to recalculate my VE table (not using MAF on this engine). Is there a way to calculate the change it will produce on my VE table, for example: If I increase my IFR by 10% or decrease my IFR by 10%, then my VE table should change by "X" amount? Is there any system out there that auto adjusts tables for changes such as IFR (just curious).

Also, what is the difference between "VE" Tuning and "Auto VE" Tuning? Still trying to get all the terminology down.

Thanks again.

[joecar]

VE and IFR can be scaled together... e.g. increase by 10% both IFR and VE together (in the same direction).


VE tuning is "what you're trying to accomplish"

AutoVE and Calc.MAFT are two methods of doing VE tuning.

AutoVE can be amended/updated by using the newer WO2BEN pid introduced by Calc.VET/Calc.MAFT.

AutoVE us a subset of Calc.MAFT.

[joecar]

AutoVE disables MAF and CL/LTFT/STFT, and then uses wideband to correct VE table.

Calc.MAFT disables MAF, and then usen uses wideband and LTFT to correct VE table and calculate a new MAF table; also note it can optionally disable CL/LTFT/STFT and use only wirdeband to correct VE and calculate new MAF... if you ignore the MAF calculation, it becomes AutoVE.