All this 'maybe this maybe that' only wastes time and empty your pockets. If you want to 'fix' it there is a thread for that.
Ahh, right! Your thinking 'but I don't have a surging idle'!!
Well do the list step by step, don't skip around (I think it says that in the first couple paragraphs) keep notes of the results, the next step depends on the results from the one before.
One thing I will add, you could install a fuel pressure gauge, temporarily zip tie it to the wiper arm and monitor your pressure while you drive it.
Help me create the "Surging Idle Checklist"
Updated 26-Oct-2019 to clarify creeping idle RPM increase as the car is being driven. Many of you are familiar with the "Cranks OK, but No Start Checklist for Fuel Injected Mustangs" checklist and the No Crank Checklist. They are very effective in finding and eliminating the problems by use of...
forums.stangnet.com
Well do the list step by step, don't skip around (I think it says that in the first couple paragraphs) keep notes of the results, the next step depends on the results from the one before.
One thing I will add, you could install a fuel pressure gauge, temporarily zip tie it to the wiper arm and monitor your pressure while you drive it.