Intermittent High Idle Issues

Hi everyone! I’ve been having issues with my 96 4Runner with the 3.4 in it. The idle seems to have a mind of its own. More often than not, it shoots right up to about 1700 rpm in neutral or park and around 1100 when at a stop in drive or reverse. Other times it functions properly. When it’s in its high idle mood, shutting it off floods it, meaning I either have to let it sit for a few minutes before cranking again or put my foot the floor and hope it starts. I initially cleaned the TB, TPS, and IAC but ended up replacing the IAC and TPS. This seemed to temporarily fix it immediately on the first start after replacing either of them. However, subsequent starts have the same issue. It does the same thing after disconnecting both the IAC and TPS while it’s running or before starting it. Could it be a fuel injection issue instead of an intake issue?

 

Also, I should mention it can start and idle like it’s supposed to occasionally, but after a minute or two of running, the idle will shoot up.

 

CEL? Any codes?

It doesn't sound like an injector issue. Sounds like the ECU doesn't know what's going on.