I have the 72/70mm Erik's racing throttle body. Even though idling is a little high at 1100 rpm, I love the improved throttle response!!! Problem is without any throttle when the car is moving even though in neutral the rpm stays at 2000 rpm and will only fall when the car has come to a complete stop for over 1 sec.

Here are the situationsfor the situations below no throttle is applied)

1.)You're fully stopped on a downhill in neutral idling is at 1100 rpm.....you let go of the brakes and the car starts moving. About 2 secs later once the speed reaches about 5 km/hr (not exact) the rpm will rise to 2000 rpm automatically and stay there regardless of the increase in speed due to the downhill and will stay at 2000 rpm untill the car comes to a complete stop for over 1 sec.

2.)You're driving on the highway at 100 km/hr on 6th gear.......your rpm at this time is at about 3500 rpm.......you then pop into neutral and your rpm will drop to 2000 rpm and stay there regardless of increase in speed due to downhill or decrease in speed due to uphill. It will stay that way intill the car comes to a complete stop over 1 sec.

Every mechanic that I've spoken agrees that it's the new throttle body but non of them want to fix the problem. They all rather me to just reinstall my oem throttle body!!! Talk about finding the easy way out!!!!!

Why is it only like that when the car is in Motion? It's like an unseen hand is opening the throttle plate when the car is in motion and refuses to close the throttle plate untill the car comes to a complete stop over 1 sec. I know it's not a sticking throttle plate because as I described in situation #1 above the throttle plate will open by it self to 2000 rpm without any throttle being applied. I'm guessing that it has something to do with the TPS. The TPS could be sending a higher voltage to the throttle plate when the car is in motion. Only a guess........I need help.

 

Sounds like a vacumm line, maybe not put back on right?

See if someone has a pic of how the lines attached and check that.

 

I doubt it is a vacuum line. If it were, you'd have a CEL.
First, let me get something straight: Did you ever do this goofy stuff with putting it in neutral at speed and letting off on the gas when you had the OEM throttle body on???? I'll bet if you did, it would have done something very similar but maybe the actual rpms varied from what you see now. I say "goofy" because most modern day fuel injected cars have a complicated way of maintaining idle based on throttle position, road speed, MAP signals, etc. When you do this goofy thing, you are confusing the crap out of the ECU - SO STOP IT! (It doesn't hurt anything but you get what you get when you do it.) When you are at speed and you put the car into neutral with your foot off the gas pedal, the idle will be artificially held high till the road speed comes down. That's just the way it is on all but a few types of cars.
The new throttle body "might" have something to do with what's going on. It is most likely letting much more air through the bypass into the Idle Air Control mechanism. More air needs more fuel and thus a slightly higher idle. When you put on the new throttle body, did you do the throttle position "learn" procedure? If not, this is possibly why things are more "odd" than usual. It's a mult-step procedure that is outlined in the Helm manual. Whoever put the TB on should have known to do this. Take it back and get them to finish the job.

 

what's this learn procedure?............
It would be easier for me to talk to the shop if I at least understand the fundamentals of it. I thought all you had to do was reset the TPS and that's it?

 

Sometimes, it's necessary to help the ECU figure out what the voltages are supposed to be when the throttle is fully closed and when it is fully open. There is a set of steps that you can take to do this. I can't remember the exact steps. It has been posted here before. The Honda tech should know this but he'll have to check what the voltages are first and then decide the next step to take.

 

The idle learn procedure is simple and boring.

Turn the car on and let it run (or drive it) until it gets hot (fan comes on). Then turn off ALL electrical drains (radio, lights, HVAC fan, etc.). Then let the car idle for five minutes.

If the radiator fan comes on, don't count the time it is running. (So if it runs for one minute, total time at idle will be six minutes, etc.)

Once the five minutes are finished, you are done.

 

I had a vacuum line come off of the intake manifold and it gave similar symptoms. I found myself using the clutch to slow it down to idle before I found the problem. No CEL.

 

Thanks, Mike. I knew someone posted something about this once.

 

alright....I'll go have a look at the intake manifold to see if any hose is not connected. Is the "idle learn" same as the "throttle position learn"? I'm getting a little confused now...............

 

There is no "Idle learn" as such. The ECU will learn this on its own after several driving cycles. 1100 rpm idle is not a surprise considering that you've changed throttle bodies. You car may never idle like it did with the stock TB. The weird stuff that's been happening with your "idle" is because you have been doing goofy things to confuse the ECU (throwing it into neutral with gas off when you have significant road speed). Quite frankly, it doesn't even sound like you have a problem. You shouldn't even worry about the TP sensor learn thing.
If you don't want it to idle at 2000 rpm then DON'T run it up to speed and put it in neutral. You're making a problem that really doesn't exist.