I get random misfire, sometimes light comes on.

[3X00-Modified]

When i could get all the 3100 injectors firing it

This statement makes me wonder what issues you had to say "could"... That would definitely change your results vs what I've seen.

[themixer]

this is why i am no expert, my set of 3100 injectors to fire properly sometimes if i lightly tapped the fuel rail while the car is running. anyways hoping 3400 swap will fix all of that, got the engine for less than a set of injectors

[Beretta1234567]

I went to the junk yard, found a 1993 Beretta (3.1L MPFI v6) with only 83K miles on it. I got all 6 of them injectors.

I then went to a 1996 Beretta z26 (3100 SFI v6) with only 130K miles on it. I got all 6 of them injectors, these have a green band on them.

So if I understand this right, the 93 injectors are 15 lb injectors. and the 96 injectors are 19 lb injectors.

I have a chip from motorvation, I can always get it re-flashed, but it supports N/A and boost.
I will install the 19 lb injectors, and if it doesn't like it, I'll use the 15 lb ones, for N/A.
But when I install my S/C I'll install the 19 lb ones.

What do you think?
I checked them and they look nice and clean inside and out, these cars were clean, just rusted to death.
I'm considering using brake parts cleaner to help clean the insides out, or should I try something else?

EDIT:
The clips that hold the injectors to the fuel rail, I realized that the 3100 ones had different clips.
Do you know if the 3.1L MPFI clips will work on the 3100 SFI injectors, when I attach the 3100 Injectors to the 3.1L MPFI fuel rail?

Or did you do something different when you switched them up?

[themixer]

3.1 clips will work on the 3100 injectors without issue

[Rettax3]

Sounds like you have a good plan going. I am interested in hearing more about this 'motorvation' chip you are using, and how it can be 'reflashed', like an OBD-2 ECM? Sounds very cool... Do you have to send it back to them for re-programming, or can this be done by you somehow? What did it cost for the chip, and does 'reflashing' cost anything?

[3X00-Modified]

please READ what I posted don't SKIM IT, that's what spreads false information. Not sure why the 96 injectors have a green band but they are NOT 19lb injectors.

Yes I've done a 3100 injector swap into a 3.1L for someone and the car ran fine.

VIN T - 1989-1993 3.1L 189cid V6 MFI
#17102747 {ACDELCO Part # 217267} {replaces 217-255} CODE 5235136
Max Flow: 15lbs(1.952gms/sec) OR 16.6lbs depending on source
Supply Pressure: 43.5PSI(300Kpa)
Multec1 TFP

And there is incorrect info on 60degreev6 stating this

VIN M - 1993-1998 3100 SFI V6 - 189cid
#17113572 {ACDELCO Part # 2171388}
Max Flow: 19lbs
Supply Pressure: 43.5PSI
Multec 1

This pressure rating is only true for the 3400 engines in 99... the 94-98 3100's were only 17lb/hr. GM tagged the rings on the injectors to show this too, 3100 was a black ring and the 3400 was a red ring, externally they were exactly the same so they had to have some way to show a difference.

So if you figure the stock injector is 15-16.6 and the 3100 is 17 max... it's so minuscule of a change you wont really need to fix the ecu.

If you HAVE the ability to calibrate and flash the computer and your doing other things then yes by all means I would suggest doing it but for a fix on a daily car it's not enough to concern yourself with.

themixer, I can almost guarantee that when factory your BLM was not at 128 and are you sure they were 3100 injectors? Stock calibrations on cars are never in the sweet spot.

[Beretta1234567]

Ooh, oops. I had read it, I just misunderstood it.
I was on one part and switched some things up by mistake.

Then I am fine. My chip will run it.

The chip is an IC flash programmable replacement I bought with tuned settings for performance.
With a programmer and if I get a copy of the Rom for the chip, I can refresh it.
They didn't burn the programming pins like the factory Does.

What I find disappointing is everything we have to do to unlock and mod things.
You thing automakers would have made it so things could be modified for the users interests at this point.

Like computers, power saver vs performance.

[3X00-Modified]

You thing automakers would have made it so things could be modified for the users interests at this point.

Like computers, power saver vs performance.

Strict emissions standards prevent automakers from making that stuff "open" to end users.

[Rettax3]

What I find disappointing is everything we have to do to unlock and mod things.
You thing automakers would have made it so things could be modified for the users interests at this point.

Like computers, power saver vs performance.

I am not surprised by the lack of 'access' at all -I have little doubt that the manufacturers would make their computers (and even the engines for that matter) EXPLODE if you so much as looked at them sideways with a screwdriver in your hand. "Oh, problems with your old car? WE can fix that for you! (No one else can.) Here is a bill for, wow, exactly twice the amount of a down-payment on this nice, bright, new shiny car, that has no problems with it at all!!! (Yet.) Here are the keys, would you like a test-drive?"
Then, as 3X00 Modified mentioned, there is the government. Now, you cannot even buy a LAWNMOWER with a mixture-adjustable carb.