CMFI is not OBDII compliant. It only has one fuel injector: The PCM can not adjust fuel mixture for each bank independently.

 

Mine has the obdII plug

 

P0113 is either OBD1.5 or OBDII, (OBDI DTC's are only two digit). OBDII data link connectors were used for OBD1.5 & OBDII. Which image above looks like your engine? CMFI or CSFI?

 

4.3 vortec cmfi injection has the spider injection system. sprayed some starter fluid into the intake. It ran until the fluid burned up. Replaced the fuel filter. thinking that may help but no luck. Something with the fuel delivery. I can hear the fuel pump turning on. Didn't have time to check
fuel pressure. will tommaro.

Thanks for all the responses and the help. Keep them coming

 

Cool, now we're getting somewhere Always nice to know what we're working on before we start trying to diagnose it. CMFI: one fuel injector with 6 nozzles using OBD1.5 engine controls.

Key ON, engine OFF, fuel pump running, fuel pressure must be 55psi to 61psi and must remain above 50psi for at least 10 minutes after the pump shuts off. Post your results.