My RPM's were staying crazy high ....4k-5k switching gears Throttle body was in terrible shape and clearly sticking. I had a new one put in along with a new IAC valve. Also found out my throttle cable was bent and frayed. Replaced it. My clutch failed (180k on car) and had it replaced a couple days ago.

I did the relearn and watched the parked in idle rpm settle in at about 500-550, which seems a little on the low side for this vehicle.

Problem is when I get my RPMs going up to the point where I want to move up a gear, they stick, and then will return to normal after a 1-2 seconds. It reminds me of when you are driving an automatic transmission and you can feel the rpm's "settle in" to the new gear ---- I will be at 40mph for example, and when the rpms's get to about 3k, I can let my foot off gas (with car in gear) and it's like cruise control, sometimes even to the point where it is accelerating the car even more-- then the rpms go back to normal and I can throw it into neutral without a problem.

Edit: Drove around during lunch and it's getting more aggressive. Just accelerating on it's own every gear - and if I force it into neutral while it's doing this, the RPMS go to 4k+ for about a 2nd before going to normal. ???

  • What's the commanded IAC PID look like? Did you reset the Keep Alive Memory? If you move the throttle by hand does the cable seem to bind? – Ben Mar 27 '18 at 1:01
  • Is the replacement IAC Motorcraft or aftermarket? – Milison Mar 27 '18 at 1:08
  • It sounds like things are still binding for the throttle body. I would bet Ben is dead on it, like always. – Pᴀᴜʟsᴛᴇʀ2 Mar 27 '18 at 19:52
  • This is the throttle body I bought: (i.stack.imgur.com/Ees5M.png) We did the relearn where you drain the battery then restart and let idle for 15-20 min. I don't have any actual computer readouts. It's amazing how a new throttle body could have a similar issue as the old dirty one. What causes this binding you are talking about? It's a new throttle cable too. – Bruce Landow Mar 28 '18 at 2:15

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