2011 GT500 No start - Datalogged while turning over

[Hkaiser83]

My Stang went down in June or so from still unknown issues. I had it at Ford for a while but they said that one bank of cylinders has "low" compression which is causing the no start. They were sitting at 120 or so and from what I understand certain issues can cause one bank to have low compression because the injectors still fire during startup which strips the cylinder of oil. That aside, even with zero compression on an entire bank it should still start. Instead of waste more money on shops that can't figure this out I am trying to narrow down the issues. The original battery couldn't hold a charge so I've replaced it and I also worked with SCT to make sure I had a good stock tune in the computer so you can cross those off the list. Also replaced the Spark plugs.

Let me recap what happened when it died. The check engine light started to blink while I was just driving but everything was acting normal. A few minutes later I was going 3/4 throttle in 3rd to pass a car on the highway when the engine died and all of my gauges went berserk, pegging in each direction very quickly over and over. The indicator lights were all on as well. I pulled the key and tried to restart but it would not start. I had also that morning had a key made for the car since I had lost them. The car says it has 3 master keys and I found the original. I have tried unlocking and locking many times using the original incase it was just PATS that got set off. Ford claims they tested for PATS and such but I can't be sure since they were obviously trying to sell me an engine.

I datalogged most everything during startup and need some trained eyes to take a look to see if anything stands out. I don't know how to attach a file to the post so let me know of anything specific that needs to be looked at and I can take a snip-it of that figure during startup and post it.

Thanks a bunch! :rockon:

 

[me32]

If the car is modded and had a bad tune its not hard to blow a motor

 

[Catmonkey]

What were the codes thrown? Only time I've seen gauges do that is a low voltage situation. I tend to agree the engine should still start with low compression on one bank. No compression, I'm not sure.

 

[Hkaiser83]

If the car is modded and had a bad tune its not hard to blow a motor

I agree completely and have already accepted the fact that the motor may need to be replaced. But the fact remains that with as high as compression is on that bank the engine should start. So if I am dealing with a multi pronged problem I want to atleast solve the one issue before I decide to replace the engine.

 

[Hkaiser83]

What were the codes thrown? Only time I've seen gauges do that is a low voltage situation. I tend to agree the engine should still start with low compression on one bank. No compression, I'm not sure.

The only code it had stored was a misfire code. I religiously changed my plugs every 3k miles with NGK's and they never looked like they had gotten hot or damaged in any way.

Here is the voltage during startup. This is a brand new battery, freshly charged.

 

[dirtyo2000]

Bore scope to make sure no serious damage. Reinstall the factory tune just to fire it up. Last but not least if you have a buddy with one that's factory, change out the pcm.

 

[Hkaiser83]

Bore scope to make sure no serious damage. Reinstall the factory tune just to fire it up. Last but not least if you have a buddy with one that's factory, change out the pcm.

I do need to bore scope it. I have tried a factory tune, I worked with SCT on that and they made sure I had a good factory tune. Now, I really wish I had a local friend with a 2011-2012 PCM to swap out....that would be great.

 

[rotor_powerd]

I melted 3 pistons in my car and it still fired right up, albeit running on 5 cylinders and smoking like a chimney. 120psi compression is more than enough to fire, I'm willing to bet it isn't a mechanical issue.

Check for fuel and spark for starters.

 

[Van@RevanRacing]

Is it possibly flooded? Also, your voltage should be higher on start up but that should be enough to fire. Check the fuse for the alternator on the side of the battery that also contains the EPS fuse.

If you bury the gas pedal it will kill the injectors and possibly cycle the fuel out of the combustion chamber and possibly fire the engine after the fuel clears. I'm just throwing this out there as a possibility that the engine somehow is flooded.

Also, you can get another PCM and send your old one back as a core. It's not terribly expensive. It sounds plausible that your PCM is toast and you need someone withe the correct tools to do a PCM recovery or reprogram a new one.

Everything seems to point to the PCM after the replacement keys. Just my .02

 

[Shelbysteve]

same thing happend to a car that i used to own. im 99.9999 percent sure your PCM went bad. find a used pcm on line to save you money incase that is not the issue. your motor is fine, a bad motor wont cause all the crazy dash issues.

try this if you can and let know.

wish you luck.

My Stang went down in June or so from still unknown issues. I had it at Ford for a while but they said that one bank of cylinders has "low" compression which is causing the no start. They were sitting at 120 or so and from what I understand certain issues can cause one bank to have low compression because the injectors still fire during startup which strips the cylinder of oil. That aside, even with zero compression on an entire bank it should still start. Instead of waste more money on shops that can't figure this out I am trying to narrow down the issues. The original battery couldn't hold a charge so I've replaced it and I also worked with SCT to make sure I had a good stock tune in the computer so you can cross those off the list. Also replaced the Spark plugs.

Let me recap what happened when it died. The check engine light started to blink while I was just driving but everything was acting normal. A few minutes later I was going 3/4 throttle in 3rd to pass a car on the highway when the engine died and all of my gauges went berserk, pegging in each direction very quickly over and over. The indicator lights were all on as well. I pulled the key and tried to restart but it would not start. I had also that morning had a key made for the car since I had lost them. The car says it has 3 master keys and I found the original. I have tried unlocking and locking many times using the original incase it was just PATS that got set off. Ford claims they tested for PATS and such but I can't be sure since they were obviously trying to sell me an engine.

I datalogged most everything during startup and need some trained eyes to take a look to see if anything stands out. I don't know how to attach a file to the post so let me know of anything specific that needs to be looked at and I can take a snip-it of that figure during startup and post it.

Thanks a bunch! :rockon:

 

[Hkaiser83]

Thanks for all the information guys. Since I bought the car it has had strange issues. Every once in a while the throttle body wouldn't work on startup, absolutely no response. Sometimes it would start up in limp mode and restarting it would typically straighten it out. The day that it died on me I had to restart it 5 times before the throttle body became responsive.

Anyways, I have been wanting to replace the PCM for some time just because of these funky issues.

I'm also going to jack it up and check for any damaged or broken wires.

 

[rhite95]

I would say it is the PCM also. Let us know when you know something new and good luck !!