Thanks fella's. I'll do some more looking and a compression test soon, as well as carb cleaner spraying for vacuum leaks.

I dropped it off at another local shop today. They put some time into it and are going to put some more work into it next week.

Just some info from my Torque app...

Freeze frame information:
------------------
Fuel Status = 0 byte
Engine Load = 6.667 %
Engine Coolant Temperature = 197.6 °F
Fuel Trim Bank 1 Short Term = 16.406 %
Fuel Trim Bank 1 Long Term = 24.219 %
Fuel Trim Bank 2 Short Term = -5.469 %
Fuel Trim Bank 2 Long Term = 13.281 %
Intake Manifold Pressure = 6.382 psi
Engine RPM = 1,608.25 rpm
Speed (OBD) = 34.797 mph
Mass Air Flow Rate = 155.214 cfm
Throttle Position(Manifold) = 11.373 %

End of report.

41* timing advance?!

 

Freeze frame information @ idle:

------------------
Fuel Status = 0 byte
Engine Load = 2.353 %
Engine Coolant Temperature = 226.4 °F
Fuel Trim Bank 1 Short Term = -10.938 %
Fuel Trim Bank 1 Long Term = -7.812 %
Fuel Trim Bank 2 Short Term = -14.844 %
Fuel Trim Bank 2 Long Term = -8.594 %
Intake Manifold Pressure = 6.382 psi
Engine RPM = 755.5 rpm
Speed (OBD) = 0 mph
Mass Air Flow Rate = 53.824 cfm
Throttle Position(Manifold) = 0.392 %
End of report.

Per Tom Oates:

 

I had similar issues with my previous M6. Have you checked fuses? Mine ended up being the 20A "ENG SEN" fuse in one of the boxes under the hood.

 

So if you're just reading this, #5 and #7 are the misfiring cylinders.

I purchased a compression tester today:


Only had time to do 4 cylinders, but everything checked out fine:


And the plugs ... 1-3-5-7:

 

I don't know what Mode $06 test results are but here are mine:

Mode $06 report generated by Torque for Android
================================================

Vehicle VIN: Not present
Vehicle Manufacturer: Unknown
Vehicle Calibration ID: Not present

Unit and scaling information are not supplied with the data from the ECU for this type of vehicle. Consulting the manufacturers service book for this information is recommended.

Test report:
------------------
TID:$02 CID:$04
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$10
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$11
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$12
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$20
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$21
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$26
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$30
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$31
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$36
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$40
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$46
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$04 CID:$20
- High sensor Voltage for switch time calculation
Max: 32,766
Test result value: 32,770
FAIL
----
TID:$04 CID:$30
- High sensor Voltage for switch time calculation
Max: 32,766
Test result value: 32,770
FAIL
----
TID:$06 CID:$35
- Lean to Rich sensor switch time(calculated)
Max: 62
Test result value: 19
PASS
----
TID:$06 CID:$41
- Lean to Rich sensor switch time(calculated)
Max: 104
Test result value: 35
PASS
----
TID:$06 CID:$55
- Lean to Rich sensor switch time(calculated)
Max: 67
Test result value: 42
PASS
----
TID:$06 CID:$61
- Lean to Rich sensor switch time(calculated)
Max: 106
Test result value: 50
PASS
----
TID:$07 CID:$0c
- Minimum sensor Voltage for test cycle(calculated)
Max: 0
Test result value: 65,491
FAIL
----
TID:$07 CID:$0d
- Minimum sensor Voltage for test cycle(calculated)
Max: 1
Test result value: 65,491
FAIL
----
TID:$02 CID:$04
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$10
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$11
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$12
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$20
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$21
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$26
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$30
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$31
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$36
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$40
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$02 CID:$46
- Lean to Rich sensor threshold voltage(constant)
Test incomplete or dependant test failed
--
TID:$04 CID:$20
- High sensor Voltage for switch time calculation
Max: 32,766
Test result value: 32,770
FAIL
----
TID:$04 CID:$30
- High sensor Voltage for switch time calculation
Max: 32,766
Test result value: 32,770
FAIL
----
TID:$06 CID:$35
- Lean to Rich sensor switch time(calculated)
Max: 62
Test result value: 19
PASS
----
TID:$06 CID:$41
- Lean to Rich sensor switch time(calculated)
Max: 104
Test result value: 35
PASS
----
TID:$06 CID:$55
- Lean to Rich sensor switch time(calculated)
Max: 67
Test result value: 42
PASS
----
TID:$06 CID:$61
- Lean to Rich sensor switch time(calculated)
Max: 106
Test result value: 50
PASS
----
TID:$07 CID:$0c
- Minimum sensor Voltage for test cycle(calculated)
Max: 0
Test result value: 65,491
FAIL
----
TID:$07 CID:$0d
- Minimum sensor Voltage for test cycle(calculated)
Max: 1
Test result value: 65,491
FAIL
----

End of report.

 

Took it to a fellow LS1 owner. He hooked it up to his EFI Live. He stated: "I hooked up HPtuners and monitored current misfires and #5 and #7 are misfiring badly. It sounds like to me he's either got a broken valve spring, or two, or a bent valve. I told him to get the driver's side valve cover off asap and see what's up before he does anything else. "

 

Time to get at it then. A couple of people have mentioned that in this thread including myself. If you have swapped coils, wires, new plugs and checked for power at those (and injectors) then it is time to test the mechanical aspect.

I would start with either a compression check or pull the valve cover and visibly inspect for broken springs.

 

Yep, I'm hoping it's a valve spring!

Read post #44 - RE: Compression.

 

Okay, photos of the valve springs:


7:




5:


3:


1:


Valve cover:

 

Finally got to #8. Nasty:


Runs better, drives better, but still misfires on #5 & #7.

 

UPDATE: SO, I think I may have found the issue, or a big part of it. I decided today to check things I have checked already, just in case I missed something, or see if anything changed. On my way home I stopped, unplugged the MAF, reset the codes on the PCM with my Torque app, and drove. WOW.... what a difference. CEL is not blinking, it's not even on anymore. I drove it 25 miles home. The car still has minor hesitation but no big misfire. Check out these screen shots:





I'll order up a new MAF and see if that fixes things completely!

 

Random question... I know carb cleaner is obviously flammable but should it catch fire when spraying it on the engine compartment? lol. I mean, that's a sign of a spark somewhere it shouldn't be, right? The motor wasn't really hot when I sprayed it either...

 

You probably need a spark, depending on the chemical, but
http://www.engineeringtoolbox.com/fu...res-d_171.html

there are other sources of spark in an engine bay besides the spark plugs. The alternator has a lot of that going on, for example. You could have vapor start to flash in the alternator and spread to a spill site in another place.

 

Just going throw this out there, but my car did sorta the same thing. Found out it was 2 leaky injector o-rings. Hope you get!

 

I grabbed some CRC carb cleaner:


It ignited on the passenger side, near the PCV hose and also off the manifold/coil pack area (Generic shot I edited with the arrows):




Thanks! How did you verify the leaking o-rings? I've swapped in other injectors (With different o-rings) and still have the same issue. No leaks I can see either.

 

I wonder if the coil packs or static electricity could do it? I can't imagine that a stray spark would be related to this problem.

 

I smelled fuel really, then took a closer look at all the orings around the injectors and saw that I had nicks on two injectors

 

Thanks, man. No fuel smell in the engine compartment.

I'm at the point where I am driving a Ford now... '13 "Gotta Have It" Green... I'm going crazy...



It's kind of nice driving a comfortable, reliable vehicle...

 

Just an update. No new news...

 

PM me if you want to sell her. Pass your headache on to someone else haha.