2009 Z06 - Just shuts off. Heavily modded. Any help would be appreciated

2009 Z06 LS7
Heads + Cam + Headers + ported MSD + NW 103 + ID 1050x + FLEX FUEL
Lightweight clutch. E-water pump.
OS: 12628988

I tuned this car about 2 months ago. Cars been running great without issues till one day....it just dies.
Restart the car, drives fine for 2 weeks. One day while out driving...dies.
Fast forward, now the car won't stay running at all.
Starts up without issues, it's set to idle on the high side due to the large cam (and this thing likes a LOT of air) and it just dies after a few seconds. If I keep my foot on the throttle it will stay running, as soon as I let off...it dies.

I'm open to any opinions as I've tried everything I could think of to get it to run. Even swapped the TB to stock to see if anything changes (it doesn't).
Doesn't seem to be the VATS system. Ruled that one out. Car is low mileage, 16,800 miles. 400 miles on build.

It almost seems to me to be when it transitions from cranking to idle, is when it dies.


Attachment 23708

SOMFormula,

Try this:
- replace fuel filter.
- check connector/wires in ignition coil subharness.

Quote:

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Originally Posted by joecar

SOMFormula,

Try this:
- replace fuel filter.
- check connector/wires in ignition coil subharness.

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So, I’ve swapped the coil packs and the C6 doesn’t have a fuel filter
I did test fuel pressure and no issues

One thing to note, is when I start it up, if I keep my foot on the throttle, it will stay running.
As soon as I let off the throttle, it dies

I guess I’m just baffled that this wasn’t an issue before.

I have been trying to change my idle parameters around to see if I can keep the car running without my foot on the throttle with no luck. I guess what I have been looking for was a way to datalog what happens to the ECU when it goes from start up to idle mode. Is there a way to log that information to make sure my parameters are in line?

Is the fuel filter be integrated in the fuel pump module...?

Where is the FPR...?

Check for vacuum leaks.

Log ETCTP, RPM, MAF (g/s), MAP (kPa), LONGFT1/2, SHRTFT1/2, SPARKADV.

Are any DTC's present...?

Solved....

So, the shop that built the car (I’m just tuning it) did a weird catch can setup.
I pulled off the air intake and the associated PCV hose off of the intake. I disabled the MAF for testing. Started the car and oil is just dumping out of the PCV hose from the oil tank in the fender

So the intake is full of oil and causing the motor to just stop and it’s also causing issues with it misfiring and running rough

Quote:

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Originally Posted by joecar

Is the fuel filter be integrated in the fuel pump module...?

Where is the FPR...?

Check for vacuum leaks.

Log ETCTP, RPM, MAF (g/s), MAP (kPa), LONGFT1/2, SHRTFT1/2, SPARKADV.

Are any DTC's present...?

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That’s what I was doing. I even suspected the MAF (which is what prompted me to also look at swapping the throttle body)
The car came to me with a NW 103 (which tunes like a stock TB for the first 30% of ETCTP). So I swapped the TB and found tons of oil on the 103. I didn’t think TOO much about it...till I started the car (failing the MAF and leaving the intake duct off) and I observed a stream of oil dripping out of the PCV line.
So yeah, the intake (under vacuum) is just drawing in WAY too much oil and causing the engine to die.

So, I have to rethink his catch can/PCV setup to prevent this.

Thank you for the replies

LS7 has PCV integrated in valley cover (so no liquid oil should ever reach here)... has PCV plumbing been modified from this...?

edit: I just saw your "Solved" post.

Quote:

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Originally Posted by joecar

LS7 has PCV integrated in valley cover (so no liquid oil should ever reach here)... has PCV plumbing been modified from this...?

edit: I just saw your "Solved" post.

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Yes. The shop who built this car completely redid the PCV system. So, I'm having to go through it as re-think how I want to set it up.
Adding 200hp to a stock engine really overwhelms the stock PCV system. So, it HAS to be modified. So the stock line going to the air cleaner bridge will have to be a part of that equation and it will have to be modified. I'm also having too much turbulence in the stock dry sump oil tank. That isn't helping. So I'm going to have to do a quick leakdown/compression test to make sure the motor is good.

I did not realize you had dry sump system.

Leakdown is a good idea, let me know the results.