As stated in a last post, just recently did a 2000 manifold swap to my 01 ford focus Zetec. I even ported the 2000 manifold. Swap went good, however since then I’ve had a problem with the car wanting to idle up when shifting to neutral. A couple things though.
I did have a vacuum leak at the EGR pipe that runs to the intake manifold. This has been fixed and I have no more leak. I checked via carb cleaner and spraying at spots where leak was and where other vacuum leaks could be. Everything checks out. I have replaced the PCV valve and hoses before and they are good.
I also have replaced the IAC with a motorcraft one, this was done when I first bought the car and it still works great.
However my “problem” still persists.
The car still wants to “rev hang” when shifting to neutral. In idle it sits at just 650-750rpm. Normal, right? Car idles down and is happy there after a slight rev.
When driving however it’s a different story.
I can drive like normal and be fine, but once I decide to just coast in neutral after being in gear or slowing to a stop in neutral, the car wants to rev up, above to like 1100-1500 rpm and will stay there till I slow down all the way and completely stop will it go below 1000rpm. This to me is annoying. I do know that this “neutral rev hang” is normal on newer cars to help smoother shifting, but I didn’t think it was part of the programming for our cars (unless I’m wrong).
Before I did this 2000 manifold swap, the car would idle down immediately below 1000 rpm when shifting to neutral and braking to a stop in neutral and be below 1000 rpm. I would like this to happen now but it doesn’t. I’m mind boggled as to what could be a problem unless I’m completely over looking something.
The next thing I will try is to clean the MAF sensor, but I also will try to just keep driving and see if the fuel trim will level out and fix this “rev hang” for neutral coasting and driving since I just recently fixed the vacuum leak at the EGR and had the battery disconnected. I can see where maybe I’m being impatient and just need to drive the car so it will learn again, but I’d like for this problem to go away.
Has anyone had this issue before of rev hang in neutral? Am I crazy or is this normal in the programming? I just dont understand why it wouldn’t do it before if it was a programming normality to then be doing it after an intake swap. No check engine lights, so it’s not a component issue.
any help is appreciated. Cheers.
I did have a vacuum leak at the EGR pipe that runs to the intake manifold. This has been fixed and I have no more leak. I checked via carb cleaner and spraying at spots where leak was and where other vacuum leaks could be. Everything checks out. I have replaced the PCV valve and hoses before and they are good.
I also have replaced the IAC with a motorcraft one, this was done when I first bought the car and it still works great.
However my “problem” still persists.
The car still wants to “rev hang” when shifting to neutral. In idle it sits at just 650-750rpm. Normal, right? Car idles down and is happy there after a slight rev.
When driving however it’s a different story.
I can drive like normal and be fine, but once I decide to just coast in neutral after being in gear or slowing to a stop in neutral, the car wants to rev up, above to like 1100-1500 rpm and will stay there till I slow down all the way and completely stop will it go below 1000rpm. This to me is annoying. I do know that this “neutral rev hang” is normal on newer cars to help smoother shifting, but I didn’t think it was part of the programming for our cars (unless I’m wrong).
Before I did this 2000 manifold swap, the car would idle down immediately below 1000 rpm when shifting to neutral and braking to a stop in neutral and be below 1000 rpm. I would like this to happen now but it doesn’t. I’m mind boggled as to what could be a problem unless I’m completely over looking something.
The next thing I will try is to clean the MAF sensor, but I also will try to just keep driving and see if the fuel trim will level out and fix this “rev hang” for neutral coasting and driving since I just recently fixed the vacuum leak at the EGR and had the battery disconnected. I can see where maybe I’m being impatient and just need to drive the car so it will learn again, but I’d like for this problem to go away.
Has anyone had this issue before of rev hang in neutral? Am I crazy or is this normal in the programming? I just dont understand why it wouldn’t do it before if it was a programming normality to then be doing it after an intake swap. No check engine lights, so it’s not a component issue.
any help is appreciated. Cheers.
