Hey everyone,
I’m running a built FA20 with IAG 800 heads and block. The car is currently tuned for 8-9 lbs of boost and runs perfectly under boost, with clean AFRs. However, I’ve run into a misfire issue that only happens at idle and has been getting worse with colder temperatures here in NY.
During the summer, I’d occasionally get a misfire code that would either resolve itself or I’d clear it. I wasn’t too concerned since the car otherwise ran fine. But now that temperatures have dropped, I’m consistently getting a random misfire code and a cylinder 3 misfire code.
Here’s what I’ve done so far:
Sent both the direct injectors and port injectors out for testing (both checked out fine)
Replaced the spark plugs (even though the engine only has 3k miles on it)
Replaced all the coil packs
Performed a compression test (results were 150 across the board)
The car is running a stock fuel pump, 700cc DeatschWerks injectors, and a flex-fuel kit. The misfires only happen at idle and seem tied to colder weather: at 45°F today, there were minimal misfires in the logs, but last night at 32°F, the cylinder 3 misfire count climbed to 33.
I’m leaning toward this being temperature-related or influenced by oil temps, but I’m open to other ideas. Am I missing something? Or could someone take a look at my logs? Any advice would be appreciated!
