Too Much Timing or Fuel??

[onegonewild]

I have been dealing with this problem for quite some time now and cant find a resolution. I have a stroked 5.7L with a 0411 ECM flashed with the COS5 and 2002 GMC Savana tune. The issue is with starting and I can't seem to find the happy medium of proper advance on startup or cranking VE. The engine has a hard time starting and feels like there is too much advance or way too much fuel. I do know that when it fires, the AFR gauge is in the 10s or 11s. Maybe someone can look at this and give me a better approach?

I have a brand new Powermaster 12:1 starter with an Optima Red Top battery.

Tune file "FRESH" is the latest test and "Timing MOD" is a prior test.

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[onegonewild]

I have fuel injector tables dialed in, CMP retard is -1, fuel pressure is good, NGK TR55 plugs, runs great when it is warm, but issue is mainly with cranking. I am running a COS5 OS, and problem persisted with the factory OS.
Anyone?

[joecar]

Can you post logs showing spark advance (SPARKADV) and commanded fuel (EQIVRATIO) (and other pids like MAF, DYNAIR, and idle pids) during cranking.

[onegonewild]

I will do that this evening and post a log. Thanks!

[onegonewild]

I think i see the issue with the commanded AFR. So, what did I do wrong with my tune to cause this?
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[Aloicious]

all I see is commanded AFR, do you have a wideband? your cranking VE looks slightly strange, where did you get the values for that?

[onegonewild]

Yes, I have a FJO wideband and the cranking VE was just a guess trying to resolve the hard start issue.

[joecar]

I agree with Aloicious, cranking VE is wrong (and too high). Also, you maybe have a little too much spark advance.

[joecar]

What is your motor's displacement...? [ the bore would be 3.898"+0.005"...? what is the stroke...? ]

[onegonewild]

4.030 bore with 3.76 stroke
I thought the lower the value is the less the amount of fuel added for cranking VE? Factory tune has value or 75% across the board, I have 30.5-41.5%

On the latest tune, I have a value of "0" for the timing. Doesn't that retard the actual timing? Factory values are 14 down to 4 for advance. Maybe I am reading this backwards. Will B5905 have any effect on cranking?

[onegonewild]

Bump

[onegonewild]

Does anyone know what I need to adjust to make it start correctly?

[Aloicious]

I don't have access to much right now, but I'd start with the cranking VE, look for the cranking VE spreadsheet around on the forum here somewhere. that will help you get that corrected there. I'll try to take another look tonight when I have my laptop if I have time.

[onegonewild]

I have tried using that spreadsheet but maybe I'm doing it wrong. I just dont know what to set that table at to get it to start easily.
Thanks Aloicious!

[Aloicious]

your cranking ve doesn't look like what the spreadsheet would output, make sure you're using the EFI tabs and not the HPT ones.

what are your injectors flow tested at (and what pressure)? and what pressure are you running your fuel system at?

[onegonewild]

I will adjust the VE according to that spreadsheet and try again.
I'm running 2002 Camaro LS2 injectors at 55psi referenced.

[onegonewild]

I will adjust the VE according to that spreadsheet and try again.
I'm running 2002 Camaro LS2 injectors at 55psi referenced.

[onegonewild]

I have just modified the tune file and am running the tune below. Still the same results. Feels like too much fuel and engine is grunting when turning over.

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[Aloicious]

I'm stuck at work again, so I won't be able to look at the new tune until I get home. and I'm driving out to SEMA in a day or so, I'll try to get back to you beforehand, but I may not be much help here for the next little bit, hopefully someone else can help out too.

when you say '02 camaro LS2 injectors, I'm not sure what you mean, the '02 camaro didn't run an LS2, do you mean they're EV6 injectors? the LS2 used and EV6 style injector, LS1s used EV1's IIRC, but the injector style doesn't mean anything when it comes to the flow rate. Do you know what your specific set flows at?

[Aloicious]

I found an old conversation of ours where you mentioned running 24# bosch injectors (at43.5psi), if thats still the same your IFR should be 3.400 g/s for the 55psi fuel pressure. I can't open your tune right now, so you'll want to verify that it is set correctly.

[Aloicious]

took a look at the new tune file, if your injectors are actually 24# tested running at 55psi, the IFR setting is a little high. I don't see anything that sticks out...your spark tables are very odd, where did you get those numbers from?

have you ruled out something mechanical or non-tune related?

I don't really know what else to tell you and I won't be around for a week or so, hopefully you can get it straightened out, let us know if you find anything.

[onegonewild]

They are out of a 2003 Cobra and are the exact same as 2002 Camaro LS1 injectors (my fault). These are Bosch 028155849 with a Ford part number XF1E-A5B and are EV6 injectors. Do they still spec out to be 24# injectors for the 2002 Camaro? IFR will make a huge difference in my starting if I am off by that much!!

Which spark table are you referencing?

Have fun in SEMA!! That would be awesome!

[onegonewild]

Tables for minimum spark advance and cranking timing were just guesses to see if it would help the engine start any easier. I have reverted those back to factory defaults.

Those are LS2 style EV6 injectors that were told to be the new style for the 2002 Camaro.

[joecar]

Can you post the cranking VE spreadsheet here please.

Try this:
- compare your Crank/Start tables to those in a stock 2002 F-car tune... most of them should be similar, and some should be higher.
- also compare your Spark tables.

Questions:
- is your FPR manifold referenced...?
- is your 5.7L an LS1, LT1, Vortec, other...?

[Aloicious]

They are out of a 2003 Cobra and are the exact same as 2002 Camaro LS1 injectors (my fault). These are Bosch 028155849 with a Ford part number XF1E-A5B and are EV6 injectors. Do they still spec out to be 24# injectors for the 2002 Camaro? IFR will make a huge difference in my starting if I am off by that much!!

Which spark table are you referencing?

Have fun in SEMA!! That would be awesome!

thanks I'm just packing up and heading out soon, you'll want to do some research on those injectors (are you sure they're from a cobra? the cobra's had the blue giant ones which are 42#@4bar, thats what I use). ford also tests their injectors at a different pressure than 3bar, its like 39.19psi or something, its possible you've just got a wrong IFR setup in there...have your specific injectors ever been flow tested before?

all your main high and low octane spark tables are strange, you may want to compare to an F body tune like joecar mentioned.

[onegonewild]

Wouldn't an LS1 have totally different spark tables than the platform I am running? Along with VE for cranking and such?

I have a stroked 5.7L Vortec GEN I small block.
Yes, FPR is referenced.

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Do I have too much timing in the high vacuum/low rpm areas?

[onegonewild]

What gets me is in the first 8 seconds of the cranking portion of log file, GM.AFR is 5.67 AFR!!! Why would it be commanding so rich??

[onegonewild]

So I have completely built a new tune file from the base Express van tune. Ran a segment swap from the S10 components needed for the new tune and flashed over the COS5 OS. Cleaned up the "out-of-range" tables and brought the tune as close to stock as possible. Changed the VE for cranking and changed the high and low spark tables. Seems to start up a lot better!!

Now if I can just figure out what i need for A0008, the OL warm-up will be much smoother instead of AFRs bouncing.

I'm on the right track!! Thanks!

[Aloicious]

nice!