Please help with logs / stalling diagnosis '04 Cavalier 2.2

Here are 3 logs, I would really appreciate if you can look at them and tell me what you think. The car is an '04 Cavalier with a 2.2 "F" Ecotec, and is stalling and then does not start (although it did start right up after the stall in log #2). The timing looks and sounds retarded.

The thing is that is seems to "jump back" to good timing every now and then, decides to start right up and run well and 30+ degrees timing, especially when cold. But the at idle or a stop it will stall and not want to start up. I have seen jumped chains / loose tensioners on this but they usually stay retarded and sometimes rattle. I hope it's not the PCM, but it seems to function well, communicate and read and flash. Also tested the ignition control module, colis, plugs, fuel pump, level and filter, all good.

The first log I selected too many PIDs and it's slow, just a warm-up and no stall.
The second log I decreased the PIDs for faster reading, car stalls at the end.
The third log is revving and observing / hearing retarded timing.

Please advise, thank you very much for your time and help!

2 more logs of it not wanting to start at all:

FUEL PRESSURE !!! Something was dropping the FP to around 20 psi every time the car acts up. I thought it may be the regulator but the vacuum line is dry and I repaired several electrical connections such as under the relay and in the body harness by the tank. ( cleaned and made more tight ). So far it's good, it it does it again I will try a regulator. It does not leak down from 60 psi, rather intermittently drops after a long time.

I'd like to learn, what could I have looked at from the logs to give me a hint in this direction (other than common sense of course)? And what's up with the retardation? Thanks!

Are those logs of a single start attempt (i.e. key held to start position all the time)...?

If so then the RPM keeps dropping to zero, indicating a problem with the ignition module and/or the CKP sensor(s).


if there is no ignition coil signal and no fuel injector signal and no RPM indicated by scantool, then the cause is most likely to be lack of crank signal to the ECM.

Great observation Joe, actually they are many repeated start attempts around 15 or so. Thanks for your time though!