So I got the UIM/TB/etc off and my fuel system hooked up, injectors are zip tied to the rails. Key on ON and the maf flapper help open, while I spin my spare CAS that's hooked up only 1 primary injector is firing. Checked power and it's only getting like .4v to the clip while spinning the CAS. Checked my injector clip wiring and it's fine.

Anyone have any ideas why 1 injector isn't getting power?

 

short in the wiring is more than likely your issue

 

With the key on IGN, one side of the connector should show 12V while the other side should not. If you don't get the 12V, check the injector resistors.

 

Well the car is a 87(86 build date) so it's low impedance. Think my resistor box could be the culprit?

 

Trace the wiring first. You can check for 12V or just check for continuity with a meter.

 

Found a crimp connector in the injector harness where it splits off from the engine harness, removed that and now I'm getting 12v to the injector but it's still not firing. I've tried swapping in different injectors and it's still happening.

 

Think it could be the CAS not sending the signal to the injector to fire?

 

No. The CAS signal goes to the ECU. The ECU makes spark and injector ground pulses from that CAS signal.

The injector gets batt voltage from the solenoid resistor package. The ECU pulses a gnd to the other wire on the injector plug to make the injector work. You need to ohm out the wire b/t the injector and the small plug on the ECU for continuity. I'd suspect that it's another bad crimp in the injector wirings pigtail.

Or to PROVE the wire is open b/t the ECU and the injector, just leave the plug on the injector then go to the small plug on the ECU. Pull that plug off the ECU and check for batt voltage at the injector wire for the injector that is faulty. You didn't say which injector but the attached jpg shows the color of the wire at the ECU small plug for each injector.

Injector wire colors are light green, light green/red, light green/white, light green/black. Which wire is for which injector is shown on the attached jpg.