Please Help! Out of Ideas!

[johnny_b]

‘95 lt1 m6 formula longtubes and ram-air intake setup.

ive been trying to nail down an issue for the past week. When the cars cold it runs great but when it gets up to normal temps when you put the pedal to the floor it’ll bog down like it’s cutting out, it’s just falls ok it’s face at. Only at higher rpms like 3000 and up. Seems to be very rpm and throttle percentage dependent.

so far I’ve tried:

installed another used Opti
Swapped used coil and icm (re-thermal pasted everything)
swapped PCM
swapped TPS
did a speed density flash to rule out faulty maf.
Swapped to a new set of injectors

All this resulted in no change.
planning to check :

wires
plugs
Fuel pump & fuel filter (both were replaced within the last year).

It’s driving me crazy. Any input is appreciated, thanks.

-Johnny B

[kur4o]

It does sound like all cylinders failure, rather than a single one.

It could be fueling issue. Fuel pump or pressure regulator loosing it at higher temperatures.
It could be bad coil, acting strange when heats build up.

Mechanical failure is also possible, but that will be the last option you should look at.

I just saw you changed coil, so that leads to fueling issue.

[steveo]

i'd be monitoring fuel pressure with a gauge somehow mickey moused so you can see it while driving.

[LS1thunder]

Coolant Temp sensor might be acting up. Scan it to see what it shows for both conditions.

[johnny_b]

Fuel pump was the culprit. I realized the issue would only occur during PE mode.

Tank was nasty mix of dirt and rust and pump was missing the sock.

New pump and filter, all is back to normal.