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- #41
Thank you for the reply. I appreciate it.From all I have read on here, it would point first to (3) things:
Temperature Sensors in the head (You've recently done one)
IAC valve operation.
VSV valve operation.
As I think about what you have done and tested and what changes when the engine comes up to temp:
ECU goes to "Closed Loop" and the fuel pump changes speed. This is determined from the temp sensor.
This also changes the O2 sensor limits the ECU monitors.
Vacuum leaks could be a source, but unlikely.
Does the engine die or get REALLY rough if you remove the oil fill cap while running? It should get REALLY rough and nearly die when you open it. If not, you have massive vacuum leaks the ECU is already adjusting for such as valve cover leaks and/or spark plug tube seal leaks.
Possibly check fuel filters both in tank and under the intake manifold.
Check fuel pressure at idle prior to warm-up and again after warm-up.
I will check removing the oil fill cap today. I have not done this yet
I have changed the fuel filter but not the sock in the tank.