LT1 Pinging/ Missfire problem

[Firefighter Z]

Motor pinging underload

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My LT1 problem is where I would be in 4th gear (A4) and give it some gas the motor would ping and backfire at around 2000 rpm. It would Idle fine and would get up and go in the higher rpm range but as soon as I get near the 2k mark that where my problem is.


I replace "all" sensors, replace the plugs wires and spark plugs, opti is not that old, coil pack is MSD. These parts dont even have 5k on them yet. The gas is new. Tested the injectors and they passed.

My car ran fine last summer and I stored it during the winter but I started it up twice a month with no problem.

Open loop it runs fine but when it hits Closed loop that where the problems begins.

Any ideas? I'm leaning towards valvetrain issuses....

[Reverend Cooper]

i say gas....just my 02 worth and what is a MUSTANGM

[Beagle]

josh when you have time ill stop over and see whats up with it.

[Firefighter Z]

I drained out a quart of oil and threw some lucas oil in, I have better oil pressure and I went to get some gas... The noise is still there when I wanna get on it but not as bad.

[Reverend Cooper]

im telling you run the gas low and fill it up with good gas,reformulated shit is only good for 30 days and it starts to go bad.

[Firefighter Z]

im telling you run the gas low and fill it up with good gas,reformulated shit is only good for 30 days and it starts to go bad.

- Well I ran it as far as I can go dry so I dont burn out my pump. Filled her up and it runs very nicely!

- I wished the good ol' state of Wisconsin would have let me know about gas going bad in 30 days.

[Reverend Cooper]

please send check to must use a supercharger or turbo agains n/a gm

[Firefighter Z]

Wtf? Lol

[Beagle]

i hope your running premium in that thing.

[Firefighter Z]

Yep I filled her up