Hello, I'm currently having a couple of issues, I'll start off by listing all of my mods and build info just so people don't ask repeatedly haha

Megasquirt ms3-pro (aaroncake base tune and wiring diagram used)
6 port Bridgeport
9.4:1 rotors
RA classic apex seals
FD corner springs
Atkins solid corner seals
Racingbeat road race header
TII intake manifold (port matched to the 6 port)
4x550cc TII injectors, used but I know they open (not sure how well)
Ls2 coils
GM coolant temp sensor
GM exposed element IAT sensor
GM 3 bar map sensor
FFE crank trigger kit (Hall effect)
Stock TPS
1980s style ford big block EFI fuel pump (6 months old)
No Idle air control valve, egr, ect.

Now to the issue, I've gotten the car running and I've achieved an idle but the car will run at 13.5:1 or so but will randomly go 17.5:1 for a second then back to 13.5:1. It does it at a fairly predictable pattern so I've been thinking I may have a bad injector (but when I pulse each injector using the megasquirt I hear them opening) but if that were the case my thoughts would be that the car wouldn't idle. The car revs fine sometimes but sometimes sounds a little... Off, any insight would be great!

 

keep in mind that the brap brap idle of a big port is actually a misfire cycle, so it will give the o2 sensor a bogus reading.

you can still tune with it, but you need to take the AFR number with a grain of salt, because its false.

instead you should be tuning for best idle quality

 

Any tips on tuning it so if it hits that one lean spot (or the misfire) that it won't die? I have the idle set screw at 25% currently just to keep it running

 

richen it up, as well as any cells in the RPM table lower than where it is idling.

it's called a lean "hunt"

 

Keep in mind any misfire will show up as a momentary lean spike.