FIXED 2012 Honda Pilot 3.5L Start and stall, CKP/ CMP alignment waveform

I'm dealing with a start and stall issue on this 2012 Honda Pilot. It began with dying while driving. My fellow master tech found the battery had failed, charge system checked okay. Because of the dead battery, any DTCs were lost.

After replacing the battery, the engine starts normally, then stalls immediately. After numerous cycles of start and stall, no DTCs have set. All modules are reporting in a vehicle scan. The immobilizer shows no fault codes, function test reports the system is normal. ECM data shows immobilizer in RUN mode. PGM relays 1 & 2 show normal operation and output. Injector ign. voltage is normal and present with key on. Injector pulses are present during cranking, stop as soon as engine starts. Both CKP and CMP scope normal. I have visually checked crank/cam alignment, checks out okay. I tried a hard reset by disconnecting the batt cables and connecting them together for several minutes. No change in symptoms.

My next step is to check CKP/CMP alignment by labscope waveform. I'm hoping someone out there has a known good waveform they could share.

Also verified oil level, all data PIDs check out as normal. Will Honda immobilizer allow engine start, then shut down injectors? Does this sound more like a CKP/CMP alignment issue?

Any thoughts are welcome. Thanks in advance. Mark

Maybe try keeping it running on alternative fuel?

The waveform shows a known good CKP/CMP relation on a 2010 J35 AH6 engine from an Odyssey. You can download it over at Rotkee's. I would not expect the engine being shut down because of loosing sync without flagging a code though.

While some immobilizer systems (VW/Audi for example) will allow the engine to fire up for a couple of seconds before cutting injector pulses -they will flag immo related codes and turn on some kind of visual indicator - the Honda immo systems I'm aware of do not allow the engine to start at all. In case of a problem the telltale light will come on as well.

For security reasons an immo system that once has allowed engine start will not shut down the running engine during the same ignition cycle!

Given you have access to a scope I recommend to look for what goes missing (and what not) when the engine stalls.

Thank you Cheryl. I might give that a try, just to see if the motor continues to fire on all 6.

Thanks juergen. The waveform capture i took yesterday from the '12 Pilot 3.5 J35Z4 is quite different. This engine has a single CMP sensor, front bank only. I tried to post the waveform, captured on my Modis Ultra. Snap On likes to use special file extensions that no one else recognizes. I used to have a program to convert these to JPEGs. New computer, no longer have the program. I may try later today to find a download that can convert the LSM file.

If you posted the LSM file one could open it with the shopstream software from snap on using a windows computer.

If only one out of 4 cams is watched that's poor. Did you check for relative compression/bank to bank differences?

Hi again juergen. This motor is a single overhead cam with valve pause type VTEC. Still, only one cam watched, not so hot.
Update this am. The vehicle is fixed. After reviewing all I knew so far, I decided that CKP/CMP correlation probably wasn't the issue, since I was getting at least cranking injector pulse. It also wasn't the immob system since the engine was starting.
I decided to try running the engine on alt fuel so I could take a look at things with the engine running. I connected propane to the EVAP purge connection on top of the intake manifold and the engine fired up and ran fine. Using my labscope I saw that I had all 6 injector signals, just very narrow at about 1.8mS. I decided to try an alt fuel source through the fuel system, connecting the Motorvac to the fuel rail inlet, just in case there was a problem with the fuel in the tank. Again, the engine started and stalled. Increasing pressure helped slightly but still no dice.

I went back to propane and with the engine idling I looked closer at data. I saw 1.8mS injector pulse and 1.8g/s MAF. I opened the air filter housing and found it full of debris, a large chunk of which had lodged itself in the MAF sensor. I cleaned the MAF, cleaned out the housing. The engine starts, runs, and drives fine.
In a follow up interview with the vehicle owner, I learned that the vehicle had been serviced two drives before it died in the road. Maybe knowing this would have helped before diving in. The key here is don't overlook the basics.

Thanks to Cheryl for remining me to try alt fuel. That's what led me to a solution. Thank you juergen for taking the time to help me.
As far as posting the LSM file, that file type isn't supported by this forum, which is pretty common. Snappy seems to be the only one using that file type.

Thank you for the update, great to know it's fixed!

If necessary in the future you could upload LSM files to cloud, Google drive or something similar and share the link...Hope you don't have to.

You can also take a screenshot and post a section of a waveform as a JPEG, BMP or PNG