08GT Turbo Car Power cuts under extreme load.

[mustang1200]

So starting about a week ago the car started acting strangely. Basically under extreme load (ie. Full boost and WOT) the electrical system shuts down for a split second. Almost as if someone turns the key off and back on instantly.

Things I've checked. Alternator voltage during a pull maintains 14.3v or above. A load test shows 14.7v average. The battery was replaced 2 months ago and tests good. It is relocated to the trunk but has been for 3 or 4 years with no issue. Checked all battery connections, chassis and engine grounds, checked ECM connections and checked for bent or damaged pins.

About the car. It's a 2008 Mustang GT with a built shortblock, stock heads, custom cams, FRPP intake and S&H single turbo kit pushing 24psi. Car also has a t-56 swap.

Below is a video of the what happens to the dash when the problem takes place. Let me know your thoughts. FYI - The check engine light is P0012 - "A" Camshaft Position - Timing Over-Retarded (Bank 1). I've yet to resolve this issue after a recent cam swap.

https://www.youtube.com/watch?v=YWuyESQIiLc

 

[pacettr]

Sub'd

 

[roberts]

sub'd as that is strange!

 

[Macman45]

So starting about a week ago the car started acting strangely. Basically under extreme load (ie. Full boost and WOT) the electrical system shuts down for a split second. Almost as if someone turns the key off and back on instantly.

Things I've checked. Alternator voltage during a pull maintains 14.3v or above. A load test shows 14.7v average. The battery was replaced 2 months ago and tests good. It is relocated to the trunk but has been for 3 or 4 years with no issue. Checked all battery connections, chassis and engine grounds, checked ECM connections and checked for bent or damaged pins.

About the car. It's a 2008 Mustang GT with a built shortblock, stock heads, custom cams, FRPP intake and S&H single turbo kit pushing 24psi. Car also has a t-56 swap.

Below is a video of the what happens to the dash when the problem takes place. Let me know your thoughts. FYI - The check engine light is P0012 - "A" Camshaft Position - Timing Over-Retarded (Bank 1). I've yet to resolve this issue after a recent cam swap.

https://www.youtube.com/watch?v=YWuyESQIiLc

Faulty VCT sensor or Cam Position sensor on that side?

 

[mustang1200]

Cam position sensors swapped side to side with no change and the vct solenoid has been changed with no change.


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[QuickShift281]

Have you logged Variable Cam Timing? See what the values are doing under heavy load?

 

[mustang1200]

Yes but to be honest I'm not sure if it looks correct or not.


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[Macman45]

It's rare but possible a short in the wiring harness wires or pigtail of one of the sensors. Sounds like a short really.

 

[mustang1200]

Just measured the resistance between each vct connnectors and they measured the same.


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[Macman45]

Just measured the resistance between each vct connnectors and they measured the same.


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But it only occurs enter WOT/Full load, indicating the possibility of a connector or wire that loses connectivity briefly. Would most likely work fine with the car sitting there. I'd harass the harness a bit while you're ohming it out to see if the values change.

 

[tigerhonaker]

Corey,

Take it and have it put on a Dyno where it's strapped down and see if it does it.
(Then if it's strapped down really tight where it's not flexing so much it might show it's not a mechanical problem)

If it does not then like the other guys have suggested something in the wiring harness is breaking connection.

Might be a quick way to resolving what's going on in regards to the wiring harness being the issue.

One thing for sure at this point you don't have anything to lose but lots to gain.





Terry

 

[mustang1200]

Yeah. It will be on the dyno is a week anyway. Just trying to sort it out before I get there. Thank you for the suggestions.


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[saleen07gt]

I'm wondering if the VCT needs to be locked out when running that much boost.

 

[mustang1200]

I don't think so but this is the most boost I've run through a 3V. I'm replacing the phasers and triple checking the timing events then putting it back together.


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[saleen07gt]

What do you have the spark plugs gapped at ?

 

[mustang1200]

.022

 

[aleborjas]

is not missfire the car shuts off then goes back on looks like a ground to me

 

[mustang1200]

That is correct. It didn't misfire. It's as if someone turns the key off then back on very quickly.


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[aleborjas]

its something electric on the car... not something on the engine!