Negative Timing During Hot Restart

[06300CSRT8]

Still chasing down a long hot restart issue. One thing I have noticed is the commanded spark during hot startups is -12.0 to -13.5 in most cases. Seems awfully retarded, car has a fairly large cam (230/240 duration, 116+2 ICL, .600 lift). I assume what is allowing this negative timing is the Minimum Spark Startup table, which after 2.4 seconds (I assume this is since last startup) allows -64 degrees.

The car fires perfect every single time on cold starts when engine is completely cooled (5-6 hours). But on hot restarts, anything more than 10min or so, car will crank and fire after about 7-8 seconds of cranking. No throttle input makes any difference, and have played with the Startup Injector Pulsewidth table until I was blue in the face, made no difference at all. So now I am trying timing adjustments.

[Homer]

I might be talking out my arse...but could it be IAT hot spark table taking affect as a result of heat soak while sitting?

[06300CSRT8]

Don't think so, in the log I have IAT was 46*F. Don't think those kick in until the car is started?

[06300CSRT8]

See log attached

Negative Timing Hot Start.hpl

[06300CSRT8]

Actually looks like my startup timing is following MBT Intake Calibrated, Exhaust Lockpin, I am at 0.44 aircharge while at startup and I see -12.5* of timing in that spot. The Minimum Spark Startup shows -64* in the 2.4 second column, so I assume it is headed towards that value but then capped by the MBT Intake Calibrated, Exhaust Lockpin table.

I have all my VVT completely disabled and a comp phase lock installed, so I assume my tune will follow all the lockpin tables?

[06300CSRT8]

So i made every single table that had any sort of name relating to startup have no negative timing. Also changed my min startup table to have positive values, and changed my High ECT startup value from -5 to positive 5. No change, with key on, engine off, timing reads -64, which matches my stock Minimum Spark Startup table, and then moves to -12 or so during cranking.

Looks like I am missing some other table(s) for changing startup timing??

[Homer]

What about Baro Spark...my stock tune can pull as much as -8 degrees in the airflow/RPM range of start-up?

Ah, nevermind I see spark delay controls when ECT/IAT/Baro kickin and on my tune it is 5s.

[06300CSRT8]

Yea i zero'd those all out just to be certain anyways, didn't change anything.

[06300CSRT8]

A good test last night....switched to e85 and car acted identical to on 93. Fires up immediately when cold, cranks for 5-6 seconds before it finally lights off when ECT is up to temp (175*F or so). Shot an email to support with the log showing my negative startup timing and how my tune changes had no effect.

Can anyone else confirm their cranking spark?

[Homer]

If no one responds, I can log my hot start up and post it up later today.

[06300CSRT8]

Thanks bud, would be appreciated.

[Homer]

Thanks bud, would be appreciated.

Here is the hot start log and current tune so you can compare. I see -8.5 at start up.

hot start.hpl
11-6-2018 tune.hpt

[06300CSRT8]

Looks different than mine, yours is 0* until it actually fires up. Mine sits at -64, then goes to -12 during cranking.

[Homer]

I must not be viewing your log correctly. When I open it I see +4 degrees before you crank and around -12.5 degrees during crank. Just quickly replotted to make sure.
timing.JPGcrank.JPG

[06300CSRT8]

Sorry check out the attached....

Hot Restart 1.hpl

[Homer]

Ah, I see it. Do you have PID that shows actual spark...maybe try a non SAE - vehicle specific PID?

[06300CSRT8]

That is final spark advance

[Homer]

I wonder if it is GPEC2 related? Would be interesting to see if someone with the same PCM observes the same negative pre-crank spark. Although what is the deal with the first log...it showed +4 pre-crank? Although all your temps were cooler in the first log, however both seemed to be in the -12 range when the engine fired up.

LoL, sorry to basically repost your question.
Logs.JPG

[06300CSRT8]

Whelp i resolved the hard start issue anyways, it was all fueling. I put in the stock values for ECT above 100*F and then cut them in half. Fired up every time when hot.

Bigger issue is the two rods that exited the block yesterday at a track event....Not sure I can tune that out.

[Homer]

Can't you just change the engine displacement in the tune to 4.8L....kidding. That truly sucks.