Newbie. Need help tuning after installing a mild cam.

[bluething]

Here's the log. I had to re flash to the previous 1.6 version of the tune. 1.7 had the LTFT turned almost all the way up in the scanner. Also I drove for a short (8 min) drive with the transmission output speed sensor disabled to see if it would prove my theory of the speed sensor having something to do with the idle issue, and it stopped the high idle issue, but the car was a little sluggish on acceleration and idled a little erratically at stops. Then I re-activated the sensor and started this log after I did that and something happened that made the high idle issue a bit better while in drive. I still need help with dialing in my MAF and VE tables.
1981 Cab log14.hpl

[LS ROB]

Here's the log. I had to re flash to the previous 1.6 version of the tune. 1.7 had the LTFT turned almost all the way up in the scanner. Also I drove for a short (8 min) drive with the transmission output speed sensor disabled to see if it would prove my theory of the speed sensor having something to do with the idle issue, and it stopped the high idle issue, but the car was a little sluggish on acceleration and idled a little erratically at stops. Then I re-activated the sensor and started this log after I did that and something happened that made the high idle issue a bit better while in drive. I still need help with dialing in my MAF and VE tables.
1981 Cab log14.hpl

Post your current tune as well...

[bluething]

Here you go
1981 GMC Caballero Tune-1.6.hpt

I also attached the 1.7 file. 1.6 is the one i'm currently using

[LS ROB]

So, i added more to VVE and MAF. You sure you dont have a vacuum leak somewhere? That VVE is looking nothing like what would make sense not to mention the idle hang which is an indicator of too much airflow. Aside from checking for vacuum leaks, i'd verify fuel pressure while under load. I'm not a pro so my knowledge is limited, but i'm not so sure that i'd run a 2bar Map sensor for NA setup. Also, you will want to verify if 30lb injectors is sufficient for your cammed setup and that you didn't buy the cheapest components on the internet since most everything has chinese fakes nowdays.

1981 GMC Caballero Tune-1.8.hpt

[bluething]

Here's the log. 1981 cab log 15.hpl
No vacuum leaks. Ive checked with a fogger twice and watched it fill up with fog to the point it was coming out of the air filter.
The only non-GM mod on my motor is the cam. The injectors are stock for my motor, as well as the map sensor. Both were on the intake when I pulled it.
My cam is a very mild cam. Its a scoggin dickey cam designed to give the motor some more power without upgrading fuel injectors. Ive looked at the VVE table on a graph and I agree it looks pretty wonky. Shouldn't it be looking a bit smoother?

[LS ROB]

Here is an updated file. Seems its still needing fuel added. The VVE could definitely be smoother and i could hand-build it but even then, those numbers just look overly inflated. I looked in the repository for a gmc envoy cal, but didnt find one for comparison. I think the issue may possibly be due to the parts used; MAP, MAF, Injectors. We will see what this file does and I may have to bow out after that to let someone with more experience take a look and verify parts needed. Good logs btw.
1981 GMC Caballero Tune-1.9.hpt

[bluething]

1981 cab log 16.hpl
Heres the log for the latest. Getting better. Been looking around my area and found a place that has a dyno. Place called Avid speed. They seem legit, how much does a dyno tune typically run?

[LS ROB]

Trims look much happier on that log but the VVE still doesn't make sense to me. I cleaned up a couple of lean spots in the MAF and VVE. Not sure if you would be able to tell it or not but it seems much better than what it was. As for dyno tune, I have no idea.

1981 GMC Caballero Tune-2.0.hpt

[bluething]

Heres the log. Seems to lean out when Im cruising up a hill on a highway going ~40-50mph. Car will begin to surge but stops once it is either dropped to third or tops the hill. Hesitation off idle is still present but not as bad, but as for the hanging idle its gone. I also tried messing with the throttle control and let it adjust itself based on the rpm instead of VSS to see what it would do. It stopped the stumbling, but it would surge for a second from a stop and then be fine. only problem is when I was stopped on a hill and began going up the hill, it went into limp mode. After that happened I swapped back to the VSS controlled throttle.1981 Caballero log 17b.hpl

[LS ROB]

I will say this, MOST of the time alot of issues can be cleaned up with proper MAF and VVE tuning. Minimal "other" changes will need to be made after those are dialed in. Changing this and that in between logs and tunes can make things challenging when trying to address said issues especially if the tune and log don't match. So, does this log include data from the VSS throttle controlled settings or no?

[bluething]

Yes, in this log the throttle is controlled by the VSS.

[LS ROB]

Im not sure how much that effects things, but i'll take a look at the log and see what can be done with it. My knowledge is limited overall, but odd enough, i can do what most fail or refuse to do and that's MAF & VVE. Post the tune IF its different than the last one i sent you.


1981 GMC Caballero Tune-2.1.hpt

[bluething]

1981 Caballero log 19.hpl
Heres the log. Quite the difference it made too. Car no longer stumbles on hills and drives much better. coasts at 700rpms which is exactly what I wanted!

Only thing left to sort out is the off idle hesitation. I appreciate what you have done for me here, thank you.

[LS ROB]

Tweaked a couple of lean spots on MAF & VVE. Get a log of where it hesitates on acceleration.

1981 GMC Caballero Tune-2.2.hpt

[bluething]

1981 Caballero log 20.hpl
Here it is. Pretty much what I did was do a bunch of stop-starts from a stop after the idle settles from the previous stop-start. The rpms will hesitate a bit while the throttle continues to open more. I did a couple of them on a hill and it seems to be more noticeable then.

[LS ROB]

Did you happen to get gas recently? Everything is showing lean again. I think transient fueling could help with this, but i do not know how to adjust transients. May want to enlist the talents of some of the well known tuners on here. I made a gross adjustment to to MAF and VVE again to see if this is "better or worse." If better; then, good deal but at this point i'm tapped out and not sure how else to approach this as the VVE just doesn't make sense to me.


1981 GMC Caballero Tune-2.2 gross adjustment.hpt

[chadtunes]

Hey,

I've been looking at this too, can you add pid's - engine torque, volumetric efficiency and manifold air temp? I want to be able to calculate the P-ratio but I'm missing some information.