Hello, I have 1996 z28 that I recently completed an engine rebuild/ EFI Connection LSx PCM conversion in.

Here is what I have determined so far:
The starter is turning over
The fuel injectors are firing - I can smell the fuel
The coils do not seem to be firing. I have battery + voltage at each coil. With key on, I have 12v, and cranking it over I have 9.75v. The injector control wire is getting .2v, however I do not know if this is in range for firing the coil?
A scan tool shows RPM of about 125 - 150, which is one indication of a functioning 24x waveform signal.
The block to battery and block to body grounds are good. The four PCM grounds are good. The two Battery 12v feed pins show 12.2v, while the pcm ignition pin shows 12.0v with the key on.
The crank sprocket is a gm piece, matching the thickness spec given my EFI Connection.
At the crank sensor cavity C, I get 11.11v when going from cavity C to ground, as well as when going to low reference cavity B. I have checked the CKP wires for shorts an other issues.
I have also tried jumping from big yellow to purple on the theft deterrant relay. I have also checked all the fuses.
The PCM is a used 411, tuned by a local tuner for my build.

I thought maybe the battery could be the culprit, but I it is only a few months old and charges right up to 12.6v with a trickle charger. While cranking, voltage drops to 9.9 on the battery + terminal, then rises back.

Does anyone have any ideas as to what else I could check? I do not have access to an ociliscope, so my understanding is that there is no other way for me to check the CKP?

Looking for any other ideas for possible issues before I pull the PCM and get another.

Thanks,
Jahajazz

 

With hp tuners you can check Hi and Low Cam signals as well as Crank position sensor in the scanner, just have to add them to the table. If there not populating with numbers when trying to crank, then thats your problem.

 

Unfortunately, I do not have EFIlive or HPtuners. Is there any other possible way to diagnose the CKP?

 

You dont need hp tuners to monitor those parameters. If you have a mechanic friend that will let you bring their scantool home with you to check those parameters to make sure you getting those signals. There is also a good chance you might have set a code which may help diagnosing the problem.

 

I hooked up to the PCM with my Actron scan tool, and it shows no codes from the PCM. It also shows RPM while cranking. Wish I had a friend who has access to a real scan tool, or EFILive or HPTuners, but I am SOL there.

Efi Connections recommend I pickup a simple cheap oscilloscope so I can see the CKP Waveform, and verify if the PCM is getting a correct signal there. Trying to see if I can get on in-town for under $200, but looking like I will need to go online and wait.

 

If your scanner is showing rpm then you have crank signal. Pull a spark plug wire and see if you have spark. Is the pcm tuned for your injectors at LT1 fuel pressure?

 

Did you re wire your harness or purchase a new one? Have you checked for spark? Pull a plug and take a look at them....