Camaro LS3 Whipple start issue

[Hesster]

Issue with a start and die issue on my 2010 Camaro SS with Whipple and Cam. New TB, Pedal, ZL1 FP, 1050 Injectors, IAP, MAP, O2 Sensors. MAF is fine. All grounds cleaned, no pinched wires. No codes. Car will crank, and die immediately, like the TB slams shut. Usually issue is more frequent when the car is warm. I did have the car retuned last year, and it helped somewhat, but the issue is back again this year. I drained almost all of the gas out (gage read <1/8 tank) and put in 11 gallons of fresh Top Tier Summer Blend 93 Premium. Car sits all Winter, and is a occasional driver, mostly Car Shows.
Here is the wierd part - I notice after trying to start it 2-3 times, IF I PUMP THE PEDAL TO THE FLOOR A FEW TIMES AND THEN CRANK IT, THEN IT WILL START. It runs like a beast when it IS running, and no issues with driveability.
Any thoughts why this is?

Still some residual old gas in the tank?
Vapor Lock?
A sensor somewhere intermittent?

This crap is driving me crazy, and always worried the car won't start.

[Alvin]

Get us a log while it is acting up.

[gtstorey]

Tune? And log of it trying to start and of it running?

[edcmat-l1]

Hang on I got this.......

businessman-looking-into-crystal-ball.jpg

[Hesster]

Tune? And log of it trying to start and of it running?

This a few data logs.

[verlon]

@00:01:51.972 Log time ECM looses power

[Hesster]

@00:01:51.972 Log time ECM looses power

So wouldn't that set a code? And what if anything to to do about it?
No clue, as a newbie, how you read that. From which DL?

[gtstorey]

So wouldn't that set a code? And what if anything to to do about it?
No clue, as a newbie, how you read that. From which DL?

Setting codes can be dependent on what you are reading codes with. I would think that something would set in the other modules like BCM but would not show up in a P code reader like HPT or other basic reader.

[edcmat-l1]

@00:01:51.972 Log time ECM looses power

I don't see that in either log. Care to share?

[abc]

I'm not sure what's happening here but this is the area Verlon mentioned.
v loss.png

To the OP, turn the key to the on position, start the log, then turn the key to crank (start the engine) every time until you catch the start/stall issue, then show us that log. Will be interesting to see if the same PCM voltage loss occurs.

[Hesster]

Here is a DL made early during the tuning process that has some of the no starts - 1st, 4th, and 5th blips. I also was looking for codes during each DL, and once saw this, but it "went away" on it's own upon further checks, so that was very concerning.23-07-23 12-10-29.hplCamaro Codes.png

[verlon]

I don't see that in either log. Care to share?

1. MAF frequency instantly going to zero while engine speed is still above zero. That can happen only when MAF fails or its power is lost.
2. Control Module Voltage is going to zero.
Those two conditions is sufficient to declare loss of power. Since we don't know which (battery, ignition or PT relay) voltage is displayed as control module voltage further diagnistics with tech2/tech2win is required to determine which one is disappearing.
At least PT relay voltage is disappearing because MAF is powered from it.

[Hesster]

1. MAF frequency instantly going to zero while engine speed is still above zero. That can happen only when MAF fails or its power is lost.
2. Control Module Voltage is going to zero.
Those two conditions is sufficient to declare loss of power. Since we don't know which (battery, ignition or PT relay) voltage is displayed as control module voltage further diagnistics with tech2/tech2win is required to determine which one is disappearing.
At least PT relay voltage is disappearing because MAF is powered from it.

What is "PT relay" (Powertrain?), and is it something I can check via voltage or resistence checks? The MAF is OK but I can check the connection. I am looking for things I can inspect, test, etc.

[verlon]

What is "PT relay" (Powertrain?), and is it something I can check via voltage or resistence checks? The MAF is OK but I can check the connection. I am looking for things I can inspect, test, etc.

Yes, it's a Powertrain Relay. Try connecting #194 bulb to the relay coil and look will the light go out when the engine stalls.