03 blazer 02 lm7 5.3/4l60e cam swap tuning

[garyduff12]

new here i have 2002 silverado lm7 5.3 swapped into 2003 s10 blazer. i swapped the cam today. started itand recorded a log. my spark advance is up down and rpms also and im getting random misfiring light flashing. im needing some help idle tuning and where to start. ive played around a little with stock tune.
i have checked and double checked plug wires plugs and coils. they are in good order. any help would be appreciated. i have pasted cam specs in post and attached my long and current tune after swap


Part Number:
54-454-11
Grind Number:
277LRR HR13

Lifter Type:
Hydraulic Roller
Engine Family:
GM LS Gen III/IV 8 Cyl. '97-Current Three-Bolt 4.8/5.3/5.7/6.0/6.2/7.0L Engines
Description:
HYDRAULIC ROLLER-Good street/strip camshaft with a very wide range.
Cam Family:
LSR? Rectangularl Port (All Out Power for 5.7L-6.2L)
Specifications Intake Exhaust
RPM Range:
1900-7000
Valve Lash:
Hyd.

Hyd.
Valve Timing:
0.006
Duration:
277

293
Lobe Separation:
113?
Duration @ .050" Lift:
227

243
Intake Centerline:
109?
Valve Lift:
0.614

0.624
Lobe Lift:
0.361

0.367
Valve Timing @ 0.006 Lift:
Exhaust
Closes 30
ATDC
Opens 82
BBDC 109 Valve Timing Diagram
Intake
28 Opens
BTDC
68 Closes
ABDC

[kevin87turbot]

It needs a lot more airflow and a lot less fuel at idle. Does it have any exhaust on it yet? The front O2 sensors seemed to be dead.
Try this modified file. I added a lot of Airflow, removed a lot of fuel at low rpm, added fuel to upper rpm and disabled misfire detection.

shifting points 52005400 speed 9095 pe 353800 7modified.hpt

[5FDP]

On top of what he did, get a wideband o2 sensor as soon as possible. To me it's not even worth doing much until you can correct the MAF curve and VE table for the changes in fueling that is required.

I'd cut the under-overspeed spark correction tables in half too, so it won't swing as much timing.

[garyduff12]

thanks for the insight guys. kevin87turbot ill try your modified tune. thanks for your time and replys i wil keep you posted

[garyduff12]

also its does have 2.5 y piped no cat to a flowmaster 40. i do not have any 02 sensors at all but everything else is stock maf, map, knock sensors, etc.

[5FDP]

Is your plan to not use o2 sensors?

My advise is to run just the front primary o2 sensors, it will make your life a lot easier.

I mean you can tune it without them but you better be sure your calibrate everything really well because the computer has no ability to adjust fueling on the fly in closed loop without them. You will forever be in open loop with zero fuel trim control. A wideband o2 sensor is the only way to calibrate this engine in either way you choose to go.

[garyduff12]

thank you for the advice 5FDP. I do plan to get 02s here soon. wide band is on my list also.

[garyduff12]

after flashing the modified file it seems to run more fluidly, except still getting random misfire at idle only 900+ rpm doesnt get misfire flashing MIL. searching for 02 sensors right now. i have attached log and current tune. thanks for the help so far. nice to see some people are willing to lend a hand.

[5FDP]

Yeah, this is where we are in the dark. Hard to tell if it's from too much fuel or too much air or vise versa.

At a minimum you can check for vacuum leaks and make sure you are holding steady around 58psi of fuel pressure.

[garyduff12]

i made some more adjustments but for the life of me i cannot figure out why the spark is so up and down. ive played a little here and there. i disable ltft and stft and adaptive idle perimeters. adjusted the rpms though i will return to them for further tuning. i have ordered a aem wideband and display from hptuners it is on its way.
as of now the only way i can smooth the spark is to command it in the vcm scanner under spark idle correction bypass you will see in log when it is activated and after it was activated holds 27degrees at idle . i also was playing with commanded rpms so thats why those were up and down at the end. it seems to idle really rough below 850ish rpms but after a test drive its driving itself. at 0% tps it will hold 35-40mph @ 1200 rpms in 4th gear. (not shown in this log). any more guidance would be greatly appricated i really need my car again for a daily driver at least for a little longer. thanks again i have attatched most recent log and current tune.

[5FDP]

You still haven't cut the under/over speed spark correction tables yet, do that.

Try for 18-22 degrees of timing at idle.

Getting the wideband and working o2 sensor will really help you here, it's just impossible to see if it's lean or rich and causing more issues. (like a vacuum leak)

[garyduff12]

Well I've got a aem wb 02 sensor. I can't post a log currently will try to late. My spark is holding at 21? idle is more stable now. But my commanded afr is 9.8 and according to aem wb sensor it's coming out mid 11s to low 12s afr any suggestions. All adaptive settings should be off currently. Over and under speed have been zero'd out also.