Hi all,
Having some problems with the AFM of my '89 S13 Ca18det...

It is running a AFM of around 12.0 idle, 13.4 low trottle, 10.0 or lower on WOT.

Setup:
Walbro 255
Adjustable FPR
stock exhaust (for MOT) or normally a 3".
FMIC
T28
Stage 2 chip (brand unknown)
AEM AFM wideband

What I have done so far:
Installed the FPR and put it on 36 PSI when not running the engine and only the pump. And with the engine running at idle.
I have 2 gauges installed. One after the fuel filter and one at the FPR.
With pump only, FPR 42 PSI, fuel filter 36 PSI, with engine running idle, FPR 33 PSI, fuel filter 28 PSI.
Ultrasonic cleaned the injectors
switched timing from 10° to 18° BTDC

And it didn't change anything.....
I am going to do a boostleak test first but after that I dont know where I need to look anymore...

Welcome to NICO Club!

You set your FPR with vacuum unplugged yes? 10 to 18 is a big swing. Isn't OEM 15 or something? We've got some turbo CA guys here. They should be able to help.

Thanks!

Yes, 15 is oem, I just played around with it to see if it changed the afm. But it didn't noticeable.

Just dial your fuel pressure back til you hit the AFRs you're looking for.