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-   PCM Diagnostics & Tuning (https://ls1tech.com/forums/pcm-diagnostics-tuning-7/)
-   -   PCM sometimes pulls timing but can't for what reason. (https://ls1tech.com/forums/pcm-diagnostics-tuning/1686980-pcm-sometimes-pulls-timing-but-cant-what-reason.html)

mike13 Nov 5, 2013 08:37 AM

PCM sometimes pulls timing but can't for what reason.
 
1999 trans am running speed density sometimes the car will pull timing but can't find any reason why it should. I've been told that I should have my low and high octane tables the same. Also have heard there are calculations and tables not seen that affect timing.

Any thoughts?

LSX Power Tuning Nov 5, 2013 11:55 AM

It could be tons of things, post the tune I'll check the most common things.

Blown06 Nov 5, 2013 11:04 PM

Burst knock???

boostit5.3 Nov 5, 2013 11:45 PM

mines doing something similar... it gets burst knock when ever i launch the car, in turn it pulls the same amount of knock retard which pulls timing.

boostit5.3 Nov 5, 2013 11:46 PM

ive maxed the burst knock enable and zero'd the burst knock retard vs ect but i still pick up burst knock on the scanner

mike13 Nov 6, 2013 07:44 AM

Quote:

Originally Posted by boostit5.3 (Post 17803258)
ive maxed the burst knock enable and zero'd the burst knock retard vs ect but i still pick up burst knock on the scanner

don't think it's burst knock, don't see any kr, it's like it's going between unknown tables and calculations doesn't show anything in the datalogs.

boostit5.3 Nov 6, 2013 07:56 AM

theres other things that factor into over all timing.. check your iat timing tables?

mike13 Nov 6, 2013 08:06 AM

Quote:

Originally Posted by boostit5.3 (Post 17803561)
theres other things that factor into over all timing.. check your iat timing tables?

sure did, checked all the visible tables.

Chevy406 Nov 6, 2013 08:17 AM

Torque management, traction control, IAT table, ECT table, commanded AFR table... Is it running off just the low octane table?

mike13 Nov 6, 2013 08:20 AM

Quote:

Originally Posted by Chevy406 (Post 17803605)
Torque management, traction control, IAT table, ECT table, commanded AFR table... Is it running off just the low octane table?

checked all those, no not just the low octane table. It's like there's calculations going on that aren't seen in the tables.

Chevy406 Nov 6, 2013 08:23 AM

Is it an automatic?
When you are able to post the tune and a scan there will be more chance of folks helping you.

mike13 Nov 6, 2013 08:40 AM

Quote:

Originally Posted by Chevy406 (Post 17803619)
Is it an automatic?
When you are able to post the tune and a scan there will be more chance of folks helping you.

Yes automatic.

Chevy406 Nov 6, 2013 11:01 AM

System > General > System Options > BrakeTqMgt make sure that is a zero

Transmission > Torque Management disable abuse mode and zero out all torque reduction tables

Engine > Torque Management > General of course zero (or max out) tables that have anything to do with limiting torque

That's about all I can come up with off the top of my head without seeing your tune.

Blown06 Nov 6, 2013 11:44 PM

I was tracing this issue on a car once and I made a custom scanner in the hpt that monitored all timing functions. If you do that, you should be able to see where it is coming from.

danieloneil01 Nov 7, 2013 03:36 AM

Post the tune

mike13 Nov 7, 2013 07:50 AM

1 Attachment(s)
here's the tune. you'll notice how much timing I run in the "drive" table, it's for having the car on the transbrake.

LSX Power Tuning Nov 7, 2013 09:31 AM

Post the details on your setup, what are all your mods?

mike13 Nov 7, 2013 09:39 AM

Quote:

Originally Posted by LSX Power Tuning (Post 17806506)
Post the details on your setup, what are all your mods?

1999 Trans Am
390/ 4L80e
billet 83mm turbo
14lbs boost, I run 50% 114 race gas
80lb injectors

4000lb car runs 143mph.

danieloneil01 Nov 7, 2013 10:26 AM

You still run a MAF? (nevermind I see you don't) VE table looks bonkers. Injector data, Engine Size, Cylinder Vol looks wrong. Injectors will not flow the same volume when intake vacuum changes and it uses the Cylinder Vol to calculate along with your injector data for the VE table. VE table should look like a dyno sheet and not the ocean.

Why is Boost Enrichment Enabled at 110 kPa but is set to 1.00 all the way across? I know it will use your PE EQ ratio table as it's richer.

I know this doesn't help your problem but I wouldn't go into PE until you address those issues. Do you use a wideband? If so go drive around and get a log and post it up.

Try putting the MAF codes to 2 instead of 3. Maybe your car is different but when I put mine to 3 the car will not run right.

mike13 Nov 7, 2013 10:59 AM

no maf, boost referenced fuel regulator.


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