5.3L LM7 that's been rebuilt with BTR stage 2 cam. When I start it the rpms jump up to 1800-1900 and quickly come back down within a few seconds. How do I fix that? I've increased idle rpm slightly, settles in around 750 right now.
5.3L LM7 that's been rebuilt with BTR stage 2 cam. When I start it the rpms jump up to 1800-1900 and quickly come back down within a few seconds. How do I fix that? I've increased idle rpm slightly, settles in around 750 right now.
Is it a DBC or DBW? Does it have a stock throttle body on it?
Post your tune as well, so we can help you out.
DBC, stock throttle body
Subtract 5 g/s of airflow out of your startup airflow table and try it again.Originally Posted by TN69C10
Also need to make sure that your IAC count is in the 40-60 range at a warm idle in park.
Finally, make sure that your minimum airflow table is properly populated.
hptunersstartupairflow.jpg
That table is set in lb/hr which is actually about 3 g/s in the lower temps. Thats probably fine. His friction airflow in the lower temps is 10g/s, thats where i would cut first to see if it helps
1997 30th SS. Torqhead 24x, TFS heads, 223/235 cam, 4l80e, S60 D1SC 14psi
IAC count is about 110 warm
I'd double check for vacuum leaks too.
2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.
If you don't post your tune and logs when you have questions you aren't helping yourself.
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