Anybody doing Chevy V8 Silverado?

Those things are a doooog off the line. Until 2k rpms, the scanner is showing negative timing advance. I tried to disable TM on several tables thinking that was it but I'm not sure that's it. Anybody got any tips?

Burst knock settings are a heinous mistake on the
earlier 5.3 I looked at. The delta CylAir value is so
low that it will trigger BK just on the RPM run-up,
steady throttle.

Thanks. I'll try to disable that to see if it shows significant results. ;D

BTW...

Here is a log from the truck....

http://www.durhamcons.com/05silverado.hpl

:banghead:

i have been tuning my brothers 5.3, it has a major off idle bog. anyone seen this problem or know what to do to fix it?

Nick

I'm just getting started with HPTuner, but I have tweaked the Volumetric Efficiency table, in particular for my truck I have seriously tweaked the values in the low rpm/high manifold pressure parts of the table. The only time you see the engine operating there is when its floored from a dead-idle stop. That change alone has made a difference. I think the engine was really running lean there previously until the O2 sensors got the fuel trims to catch up.

PS - I've got an 03 5.3 Avalanche.

Thanks for the idea but the VE table has been calibrated. Anybody else? It's cutting timing way back. Didn't check TPS tho since it's fly by wire.

Give that thing some timing! Negative timing is killing you, everything negative or under 10 bump it up! Start there and see if that helps, slowly increase until you see some knock there, I wouldnt go above 12 or 14 on 87 octane though.

Chris

Quote:

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Originally Posted by Chris

Give that thing some timing! Negative timing is killing you, everything negative or under 10 bump it up! Start there and see if that helps, slowly increase until you see some knock there, I wouldnt go above 12 or 14 on 87 octane though.

Chris

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Have you tried this with a 5.3 truck?

Believe it or not my major bog in my GMC was the MAF. I cleaned it using electrical contact cleaner and I no longer have the bog. I am actually burning through my tires now because it is so crisp. I bought the hptuner to help me trouble shot it but it ended up I didn't need it but I figure I will play and see what I can do.

Quote:

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Originally Posted by manderson

Believe it or not my major bog in my GMC was the MAF. I cleaned it using electrical contact cleaner and I no longer have the bog. I am actually burning through my tires now because it is so crisp. I bought the hptuner to help me trouble shot it but it ended up I didn't need it but I figure I will play and see what I can do.

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Do you have a K&N air filter by chance? Usually this will happen with use of a oiled air filter. The oil from the filter will get onto the MAF and cause problems.