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guy in the videos always says " looks the same as the Ford part , works the same" No it doesn't ! He isn't fooling me.
Today I replaced my IAC again. That makes twice in 30 days.

First one was a WVE from Rockauto. It worked fine except for a 2 second starting flare up to 3,000 RPM. It has a screw near the power connector, a 1/8" square drive head in plain sight. Must have some purpose. I suspect it controls starting flare up RPMs, so the same IAC can be used on bigger motors which need more air.

For backup, I bought an Ebay clone IAC for $30, and installed it today. Starting RPMs peaked around 1,500 or so, as expected. Went for a highway drive and then back to town. A-OK until the first red light. Then the motor stalled. Oops. Next intersection, stalled again. I had to use neutral and foot on the gas to keep it running. Went home for lunch.

After lunch I took a longer test drive, both town and highway. Problem vanished. No more stalling. Must have been some weird ECU relearning glitch before lunch. If that was a one off, I'll leave the Ebay clone on the car and keep the WVE for backup. Hate doing that job a third time. Twice was enough.
 

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To me it acted like the IAC was stuck at 1200 rpm high idle for awhile
That tells me to replace the IAC. It's old and due for PM anyway. What more do you need to know.

My pressure is right there (40) per scanner. Can I rent a gauge and put on Schrader port to test it.
You can but why. I trust what Forscan tells me.

Or just bite the bullet and buy 4 new ones
That's a big bullet to bite. I would do easy jobs first.
 

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I have a mechanic friend ... would he be able to do a pressure drop test using a scanner
IDK, but I can with Forscan.

I pull the fuel pump fuse so it can't run. That prevents re-priming the pressure. Then I go KOEO (key on engine off) and connect with Forscan to read the number. It's that simple.

With engine off, my fuel pressure holds at 40 psi for an hour or more. That rules out injector leakage. It bleeds off overnight, but that's normal.

More info: www.agcoauto.com/content/news/p2_articleid/323

o_O
 

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Not a question of good. You want people to study your data for free. Maybe someone else. Not me.

A diagnosis with absolute certainty is not always possible. At some point you buy parts and take your chances.
 
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