Efi 24x Conversion Startup Issues

[jahajazz]

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

[ScarabEpic22]

Can you post the tune?

Sounds like a VATS issue, make sure your tuner disabled it. Also, did you do the wiring swap to reverse the coils/firing order or did you adjust the PCM?

[jahajazz]

My tuner said he disabled VATS, but I can certainty double check with him. I repinned the injectors and coils at the pcm.

[Gordy M]

Another option: If it is similar to the Corvette, when the battery is 12.5V or less, the PCM does not have enough juice to operate properly, this caused the C5 vettes to experience unexpected colum lock when the battery appeared healthy. Disconnect everything from the battery and read the voltage on a VOM...less than 12.5V and you are probably experiencing similar problems. Either recharge battery or try a new one or a known good battery.

[jahajazz]

I am definitely seeing less than 12.5v at the battery. After a few hours on the trickle charger, the battery gets to about 12.6v, but quickly drops to 12.2v by the time I get it back connected and try and start the car. Is it a known problem that the 411 pcm will not function if it has less than 12.5v feeding it?

[jahajazz]

I just noticed that the vin on the scan tool shows a 2001 v6 gmc van (the car the pcm came out of). Is it possible for the pcm to have a vin from a gmc van after being uploaded with a 2001 camaro v8 m6 tune? I know this is a newb question, but i just want to confirm this is not my problem.

[ScarabEpic22]

If the VIN hasnt been changed then yes, what is the OS #? Honestly it should be an 02 Camaro LS1 M6 tune, 01 will work but the 02 OS is known to be the best 512kb PCM OS to run.

I don't know what OS EFI Connection recommends, but Id use that one.

[Gordy M]

I do know it is in the Corvette I am not sure if it is a problem with other PCM's. However, if the problem occurs on those OS it is not far fetched to think it might effect others as well. In the Corvette the car would start but as soon as you put it in gear, the dreaded steering column lock would kick in and if you were lucky it went to the limp home mode but usually it would lock the column and kill the engine. They went through several software and firmware iterations and it still happened. The finally received permission from the feds to eliminate it.

[Chuck L.]

12.6 to 9.9 when cranking is way too much drop. [We've tested inj systems that won't even fire the pump at <10VDC.]
As mentioned, have the batt load tested.
Fresh injs? Just because you "smell fuel", doesn't mean all's well. [Could be due to injs leaking].
What's the fuel psi when cranking?
Injs and coils hot when the key is in the start and run position?