got my car back from dyno tune.. looking over the tune and comparing I have a couple concerns that I don't know if I should..well be concern.

1) the injector data I found was from this sight and is for the bosch 028155968 green giant injectors, it looks like the dude doing the tune change all of that data. by doing a dyno tune would he know the data needed change?
2) the DFCO is now disabled, I watched chopperdoc video and he suggest keeping the DFCO enable for fuel economy..
3) the BRAF seems super low from 212* on, cold start is not the best. It cranked over a bit after work, 80*-85* out side.
also I think they have the idle set to high. before I brought the car in I had the idle set at 675rpm and it idle nicely, the problem I did have was hanging idle while driving and letting off the gas coming to a stop. around 1300rpm. a few seconds after a complete stop the idle would then drop.
NOW the idle doesn't hang but it seems slow to drop and it hovers more around 1000 rpm. during the drive home.. about 45 min of bumper to bumper.. couple times after I left of the throttle the rpm dip down to 500rpm before catching and idle back at 1000rpm. however it did stall on me while turning on to the road to my house.
before I question the dude I want to get some opinions from those that know.. so please share your thoughts!!

 

the idle thing is the only thing i can comment on. depending on the size of the cam for the cubes of the motor, a tuner will set it to not return to idle until the car comes to a complete stop to prevent the car from dipping too low in the rpms, wanting to stall, losing power steering/power brakes etc.......since it stalled on you once i imagine it stalled on the tuner while stopping so he messed around with this. so when our cars are stock, cruising at 20 mph, push and hold in the clutch our rpms drop to basically idle.....since they wont want to stall out becuase they have3 small cams, mafs, TBs etc....

so its kinda like have 2 idles, a stopped idle of maybe 1000 rpms, and a "rolling no load" idle of 1300

how fast were you going, how hard on the brakes were you and how far was the wheel turned AKA power steering load when it stalled on u

 

I was under normal braking . And as for the speed turning .. maybe 10 +/- mph. I caught a green arrow with a car two car lengths in front of me . the BRAF set at 3.xx g/s wouldn't have anything to do with the stalling or idle dipping the few times?

 

Yea u shouldnt have stalled there. Something needs adjusted. Im not familiar with what should be changed

 

The thing is no 2 tuners will tune anything the same. Most guys don't or won't set expectations to a tuner and then get disappointed when they get the car back. I get it. Normally if a guy is taking a car to get tuned, it's because he has no idea of what he needs to do or how to get there.
The idle thing should be fixed. If you didn't specifically say you wanted it to idle where it was, he may like them higher (personal preference). IMO, this is where Dyno tuning suffers. MOST are not a loaded Dyno, so tuning tip in and slow down is much much harder on a Dyno. In the end, if he is a good tuner, call him up, express your concerns, and he should fix them without problem.
The dfco, again can be personal preference. Most guys aren't real worried about mpg, but I run it, why not?

 

my main reason I had the dyno tune done was for WOT,PE and timing adjustments. Which i got. I was more confused on how he came up with the new injector data, I thought that information was found by testing the injector independently

I agree, this definitely was my fault not communicating the idle and where I wanted to see it. I just assume he would see where i had it set and match.. my fault for assuming.

I did actually call him today and he was more then helpful, which i had no doubt he would be.. I wanted to get other views..more for learning on my part. As you pointed out. " no two tuners tune alike".

That is the same thought I have about the DEFCO.. thanks for the input!

 

I spoke with the tuner, the BRAF from 212* 3.xx g/s i was concerned about needs to be raised.. well he mentioned even maybe from 176*.
thank you for you help

 

Is your throttle body cable drive by wire or drive by cable?

What I would suggest is to go thru the steps to make sure the TPS is reset correctly so you have a baseline to start from when setting idle. The reason is because it appears your BRAF set point values aren't even close to stock or what is necessary for the cam you have. Your tuner should find the correct values and then enter based on a cold start idle log.

Another thing I would check is to make sure your IAC control value is working and is NOT stuck. Lest we forget, your car is 20 years old. If the shaft on the IAC is coked and not moving freely thru it's entire travel path, it can effect idle or hanging idle. Getting IAC steps in line is critical.

A lot of timing at idle creates torque. So even though idle is set at 800 rpm it's not coming down to 800 at idle. Increased torque at idle won't let the car idle down while moving in gear at idle..Your 'Idle Spark Advance' is set at 24 degrees. You and your tuner might follow the steps suggested by Maslic to get the idle to settle down and not stay in cruise mode with foot off throttle, in drive, approaching a stop light. A driveability log will tell you TSP position and timing during light cruise.

http://www.masterenginetuner.com/idl...ii-lsx-p1.html

Take a look at the throttle cracker table as well in the far upper left corner cells down to about 32 mph. The tuning school suggests to zero out those values to stop hanging idle.

https://thetuningschool.com/blogs/ne...p-hanging-idle

I would suggest before doing a drivability tune with your tuner that he follow this guide to adjust your transmission table shift points. With your stall at 4000 and with your cam, you will probably find that you won't get good driveability in any gear when RPM drops below about 1600 rpm. If you find that is the case, then pointless to set shift points and throttle position where you are below that threshold.

If your stock transmission values have never been touched then IMO your tuner needs to work with you to get the car to drive the way you want it - not what someone else thinks it should be. Drive like stock is very subjective. With your converter you can get close to almost stock but you will need to make compromises when setting shift points. Don't buy the argument that you need to idle along at 1300 rpm with an auto and a 4k stall when idle is set at 800 rpm. With foot off the pedal idle should not hang or stay in cruise mode - period

https://ls1tech.com/forums/automatic...tm-w-pics.html

Work with your tuner during drive-ability tuning to find the sweet spot at at each shift point at each TSP position.. What you are looking for is when the converter starts to shudder or hunt. Adjust the shiift mph to make it go away.

Pay close attentions to the instructions when setting shift down spread at 65 or 70 mph. How you adjust the spread will depend on HP and torque you are making at 70 as you pull out and pass traffic. I don't like barking the tires at that speed. Some do.

These steps might take awhile. Time is money, and most tuners what to skip this part (driveability) of their tuning.

Or get your own tuning software and log driveability yourself for shift points.

Maslic has an entire chapter devoted to the 4l60 and 80 GM tranmissions and is reasonably inexpensive. Might want to take a look at it. It's a digital file that you can view in PDF format.

http://www.masterenginetuner.com/home.html

 

The tuner should have asked you to provide a written list including items such as cam profile, injectors, heads, torque converter, rearend ratio, , etc. He is supposed to tune your car based on this information.

The data that the tuner should enter into the IFR table and corresponding fuel tables should be from the vendor for your specific injectors. I suppose it's possible he didn't know and so plugged in his own numbers.

Compare the values to what they should be based on the vendor files and what he entered. If they are significantly way off ask him why? Ask him why he changed the values.

I found the same discrepancy in some early tunes (back in the day 2005 or so) on my car. Some tuners did things like that back then because a lot of injector vendors didn't supply good data if any at all. If he is old school - perhaps he has never changed his methods.

 

dlandsvZ28, thank you for taking the time to go that in depth with your reply and include links to further educate me.!! the car is DBC, I did ask him about the injector data being changed he told me (he told it beter then I'm about to) that the reason the offset was change was because these particular injectors leak down and by lowering those values it helped with that. he also force them closed and the still showed leaking. however he didn't comment on why the flow rate change. Now I will be looking for different injectors.. might just toss my stock ones back in cuz funds are low right now ,, IDK. seems like a waste to spend any time tuning if these new injectors are not up to par. I know changes was made in his tune but i have not logged any data since the dyno tune to check IAC movement and park position. but I plan on going over it. I figured i'll change the idle and shifting to my likings. the suggestion you gave on that helps point me in the right direction. I attached the tune I was working on prior to taking it to get dyno tuned if you care to compare the two. based on the conversation I had with the tuner it sounds like he had to lower the offset on the injectors a good amount.. I planed on lowering the Idle Spark Advance around the idle areas probably where I had them. and I plan on changing IAC motor amd clean the TB.

 

Looks like he copied your high octane table over to the low octane table for the dyno tune, but then didn't adjust it later to give you a little safety margin.

 

On the dyno tune file, If I change the injector data back to what I had it set at prior to his changes how far off will the rest of the tune be off?
I came across data (under injector data sticky on here) for the GTP 36lb injectors and a lot of the data seems to coincide with the data he used. by using the 36lbs (41.5lbs @58psi) the dyno tune he did VE table,Spark table should still be within reason. is that possible?
oh.. also the spreadsheet for those 36ibs fuel to wall transient rows are different, their are more and the F* numbers are not the same as the table i'm working with. what should I do?