Okay i saved this Caravan from going to the junkyard last year as they thought the engine was bad. Turned out all it needed was a water pump, Before i changed the water pump i ran it but not much cause of the water loss, Well changed the water pump along with the timing belt, It runs great no real issues besides it being a 4 cylinder caravan so its slow moving, but the engine is slow to return to idle, Can the timing belt be off by one tooth causing this? Or something over looked while it was apart and didn't get hooked back up?

Here is a video of what i am talking about sorry its dark out... But you can hear it on start up and when i push the gas i let off right away and it takes afew seconds to return to idle.

 

Off the top of my head, check the action of the butterfly in the throttle body. if it's gotten gunked up it could be slow to return. Perhaps clean the TB and retest

 

If the engine is running well, I would not guess a valve timing issue. I've only had experience with one 4 cyl with one tooth retarded timing - couldn't get out of it's own way. Reset valve timing and 1.5L 12-V came back to life (big thanks to the Honda dealership that screwed the timing).

I have had one fuel injected engine that had a slow return to idle. 88 Ford 3.0L - vacuum line to cruise disconnected.

Check for a large vacuum leak. It's amazing what fuel injection can overcome.

 

Yea it runs great no codes has some top end chatter tho but wouldn't be the first time i heard a DOHC have that. I will check up on the vac lines, Maybe i broke one and didn't notice, The throttle butterfly closes as it should, I even cleaned the intake, IAC, no difference in it.

 

Better video in the daylight, https://www.youtube.com/watch?v=adiY...ature=youtu.be

 

Your IAC could be getting wore out which would cause it not to return to idle quickly.

 

eagerly awaiting the answer, this one is kinda bugging me and I want to know what the cause is

 

Glad i am not the only one to be bugged by this, Never have a check engine light but i remembered i pulled a code months ago P0601, Cleared the code but it always came back and never got any other codes and as said the CEL Have never came on besides when you first turn the key. I know i read before short of replacing the PCM or reprogram if you got it you got it for good,

With all my cars i pick up spare parts for what if's like when the PCM died in my ZJ i had a spare i could toss right in, if i pick up a spare PCM out a 2.4L caravan would it need reprogrammed to keep as a spare?

 

If it's same year/driveline it should be plug and play. That's how they used to be at least.

 

I don't think the P0601 would be contributing to this issue though, that's a checksum error meaning that the PCM may have failing memory modules or something of that nature. I suppose it's not impossible, but why suddenly now is it acting up if you've been dealing with the P0601 error for a while.