98 Suburban 7.4

[Spareparts]

Never tuned before and trying to learn so here goes trying to teach a old dog new tricks!
Truck is a 1998 Suburban 7.4 Vortec (L29)
My engine is rebuilt and when it was done i had .005 taken off the heads and deck so a total of .010.
Standard head gasket is .044 compressed but installed GM Performance head gaskets that measure .022 compressed.
Bore measures 4.280 with flat top pistons. Heads are 100CC Vortec. So my compression is a little higher than stock.
I installed a very mild Comp Cams "Computer Friendly" cam
So now im at the point of thinking the cam is not so friendly and with a little higher compression it's just not running like it should. It idles a little rough and has a few misfires. Everything checks out good. Compression, Spark, Injectors, Timing, CMP, Crank Relearn done.
In my stock tune i have turned off vats and turned up the idle rpm by 100 but other than that i have done nothing. I have no idea where to even start.
If someone could look at my log and tune and tell me where i should start it would be greatly appreciated!
Log-0004-1GNGK26J8WJ368764.hpl
vats disabled idle turnedup.hpt

[Hondaeater]

Never tuned before and trying to learn so here goes trying to teach a old dog new tricks!
Truck is a 1998 Suburban 7.4 Vortec (L29)
My engine is rebuilt and when it was done i had .005 taken off the heads and deck so a total of .010.
Standard head gasket is .044 compressed but installed GM Performance head gaskets that measure .022 compressed.
Bore measures 4.280 with flat top pistons. Heads are 100CC Vortec. So my compression is a little higher than stock.
I installed a very mild Comp Cams "Computer Friendly" cam
So now im at the point of thinking the cam is not so friendly and with a little higher compression it's just not running like it should. It idles a little rough and has a few misfires. Everything checks out good. Compression, Spark, Injectors, Timing, CMP, Crank Relearn done.
In my stock tune i have turned off vats and turned up the idle rpm by 100 but other than that i have done nothing. I have no idea where to even start.
If someone could look at my log and tune and tell me where i should start it would be greatly appreciated!
Log-0004-1GNGK26J8WJ368764.hpl
vats disabled idle turnedup.hpt

Try these channels and get a new log. Download this channels list. Save your current channels list using the floppy icon then using the folder with gear icon open channel config and navigate to downloaded channel list and select it.
Start with KOEO. Before start let it log a few seconds, then start, and bring it up to operating temp of 194 deg and then blip throttle a few times and let it come back to idle to check the DBC IAC. Once up to temp, if it doesn't stall and unsafe to go out on road, then go drive it around below 3000rpm. Let it get a 35-40 percent TPS and hold it there in 2nd gear from 1000- 3000rpm to get a look at the fuel trims. Do the same from 1000-3000rpm in 2nd and start with TPS about 20 percent and hold until 3000rpm or it reaches a point it stops accelerating. Get to the tps quick and HOLD, not moving tps during the accel. You can do this in 3rd too if environment is conducive. SAFETY 1ST.
Misfires, What type fuel are you using?

[Spareparts]

Thanks Hondaeater.
I'll post a new log later today.
Forgot to mention. Midgrade 89

[Spareparts]

Tried to do what ya asked. Close i think. The first minute or so is KOEO.

log2.hpl

[Spareparts]

Tried searching but i can't seem to find much on a L29.
If you were tuning it what would you start with. Im pretty sure its air and fuel that need adjusting to smooth things out but what to start with first?
Thanks.

[SiriusC1024]

Tune airflow. VE then MAF. Start with VE.

Open VCM Scanner. Clear LTFT's and fuel trims in the Fuel tab of Vehicle Controls & Special Functions.

Load this tune. SD mode (CEL will illuminate due to MAF failed). Post a log like you did. Lock it in 2nd gear. Go for a long drive and populate as many LTFT cells as possible. May have difficulties running at first. This will clear up as VE tables get more accurate.

[Spareparts]

I hope this is good. Might be not long enough?
I had a nice log for ya but naturally i closed the scanner before i saved it.
This one is shorter but might be good enough. If not i'll get a better one tomorrow after work.
Thanks for looking at this man!
LogforSiriusC1024.hpl

[SiriusC1024]

Haha that's gotta be a world record for turnaround time. Keep em coming!

It's safe to run up a lot higher RPM's. Get more cells. Check your scanner LTFT table while logging.

This time do like you did except 3x longer drive.

Clear LTFT's and fuel trims like before. Have to do this every time btw. Load this tune and go.

[Spareparts]

Sorry i will not get back to it till tomorrow after work.
Yeah, i had a nice 20 minute or so log with a lot of cells filled till i forgot to save it
I'll post another tomorrow after work.
Thanks again man you are a big help to a lot of people here!.

[gtstorey]

Logs save automatically unless you had a computer crash or something.

[Hondaeater]

Logs save automatically unless you had a computer crash or something.

Yep, Use Scanner to open a new log, navigate to HPtuner main file> VCM Scanner > Logs and it is saved by time and date. Even if your laptop battery dies during a log session it saves it in real time continuously.

[Spareparts]

Nice. Sure enough the logs are there. Good thing to know.
Sorry about the last log. I want to get you the best data i can so im not wasting your time!
Here is today's log and should be fairly decent with the abuse im putting my truck through

SiriusLog2.hpl

Forgot to mention about 5 (ish) minutes in i was stopped at a train for a few minutes.
Also do you want the logs to start from cold or already warmed up?
Thanks

[SiriusC1024]

Yeah do a cold start log. Make about 15 seconds of the log begin where it's just key on then start it and let it warm up. I'm curious about something. Make this one a separate log.

Here's the latest file. What are your thoughts on fuel cutoff? If you think it's ok to run it up in the RPM's then you'll have to do that on the next log. Cutoff is now set to 5350rpm. WOT shift at 5250rpm. Right now it's looking like you're running out of torque up top, and setting the WOT shift to 4600 (when tune is final) should do fine. Can't say for certain since you haven't yet provided good data on 4800-5200rpm. I'm not pushing you to doing that. Just stating a fact. Idk how confident you are in running it up there. I'll support your decision either way.

If you're wanting to keep it low then we're done with the SD portion. We'll move onto MAF, which will go a lot quicker. I'll post a MAF file pending your decision.

BTW how's it running compared to when we started? Looks pretty good on the log, but I'm not in the driver's seat.

- Thanks

[Spareparts]

It is running better for sure but i feel like idle could be better and LTFT is still hitting high - it looks like.
The rpm cutoff can just be stock as its not a race engine It has a stock bottom end and a Gen 6, 454 is not known to be a rpm monster anyway so that why your not seeing a lot of anything above 4k and the fear of a rod sticking out the side.
The cam is a "RV" style cam rated from 1200 to i think 5000 rpm if i remember right.
Shifting right now is fine at part throttle but at about 50% or more throttle it is to harsh but i imagine that because the MAF is disabled.
I think there has been real positive progress with out a doubt.
Ill load this last tune and log it after work tonight then post it.

[SiriusC1024]

Gotcha. We'll get to all that. Airflow first.

[Spareparts]

Just tell me what you're after for data and i'll try to get it.
The first log is after sitting all day and right after start. I don't remember if i reset fuel trims or not.
The second log is the main one with reset LTFT Action starts about 5 minutes in or so.

cool1.hpl
SiriusLog3.hpl

[Spareparts]

Been driving it around some with the last tune .3 and when warmed up it is better for sure Both idling and driving.
The last log SirusLog.3 is probably the best log so far for data.
Here is a log from almost cold to hot and some driving. No real rpm put on the engine though.

SiriusLog3.5.hpl

[SiriusC1024]

Big storm rolled in and power has been knocked out since last Thursday.

Here's the new tune to run. VE needed only a little adjustment, so we're switching to MAF.

What I was wanting was one log where the key was on but the engine not running. Then start it.

Then do a full log like you've been doing with this tune applied.

Oh yeah, buy a can of MAF cleaner and use it. Don't want airflow calcs based on a dirty sensor.

[Spareparts]

Sorry was not near a computer for a couple days.
I'll get this loaded up tomorrow morning and get the log posted tomorrow morning (ish).

[Spareparts]

Maybe it's placebo effect or something but the truck feels like it is pulling better than ever at WOT.
Here is a cold start log through fully warmed up with some WOT pulls. Near the end i don't know what happened but the laptop lost communication for some reason.
The MAF is original and cleaned twice in the last month so it is clean but 20 something years old. I do have another brand new MAF i bought trying to smooth things out but it is not a GM/ACDelco brand.

SiriusMAFLog1.hpl