93 Z28 injector bank right and left error
 

Hey guys , picked up a 93 a couple months ago. I’ve installed pacesetter long tubes , MSD opti , MSD wires , NGK plugs, nitrous outlet 100 shot plate kit, new 02 sensors and tuned by soloman @ LT1pcmtuning.com. Car runs amazing . We are still in the process of getting tuning dialed in. Over the weekend running some data logs noticed that injector bank right and left are still showing error. The car runs amazing and I need to get these errors cleared before moving forward with dialing in tuning and spraying. Any help would
be greatly appreciated.

Re: 93 Z28 injector bank right and left error
 

What software are you using for the data logs?

Re: 93 Z28 injector bank right and left error
 

Tuner Pro RT.

Re: 93 Z28 injector bank right and left error
 

OK.... I'm not familiar with that software. Looked at 100's of logs from Scan9495 and Datamaster. Also been given eeHack logs recently, but they are just too unwieldy.

Since 93, unlike the later 94/95 OBD-1 cars, doesn't have DTC 18 for the injector circuits, what fields indicate the “error” on both left and right banks? In Scan9495 (which also works on 93), in addition to the DTC log for each record, there is another column for “injector fault occurred”.

Generally, the diagnostic looks at the voltage on each circuit, and sets codes for low or high voltage outside normal limits. Since it's running great, not likely you are missing the direct 12 volt side. That would leave something like an intermittent ground from the ECM, but that would likely be felt as misfires. Last possibility might be incorrect resistance on one or more injectors in each bank. Have you checked the resistance across the two pins on the injectors ?

Re: 93 Z28 injector bank right and left error
 

Under flags , injector 1 & 2 banks continuously show errors. Injector bank driver bank 1 intermittently flashed on off. The service engine light however never is set. I just downloaded Scan9495 and will try it out later today. I have not checked resistance on injector coils as of yet, that’s probably a good starting point. What should they read??

Re: 93 Z28 injector bank right and left error
 

I can't find the values in the 93 factory manual, but it does indicate there are flags for left and right bank faults. I know on my 94, the fault (DTC 18) will set if the resistance of the injector is less than 11.6 ohms. Typical acceptable range for the Multec injectors is 11.6 to ~16 ohms.

Re: 93 Z28 injector bank right and left error
 

I checked resistance last night.. they were pretty consistent, all reading between 13.5-13.6.

Re: 93 Z28 injector bank right and left error
 

Sounds good. It would be odd to have an individual injector problem on both banks. And if you had a problem with the 12 volts or ECM driver ground to a bank, you would definitely feel it.

Strange.