[RESOLVED] New intake manifold/throttle body now high idle.

[the_mork]

So I just installed an evo3 IM and 1g TB, the car starts perfectly fine but then idles at 3200RPM. After a minute it settles down to about 2800 RPM and I'm at a loss for what is causing this.

A couple of things that are worth mentioning:

The throttle cable is slack and my throttle position according to the computer is .6%, the throttle plate also appears to be completely closed (I cannot close it more by turning it).

I do not have any coolant lines going to the bottom of the TB and I have not blocked off the FIAV.

The BISS is screwed all the way in.

I had to remove my EGR valve and I just looped the vacuum lines that went to the valve, should I have done something else?

My compressor was borrowed and did not come back with a tire chuch so I cannot BLT at the moment.


Any input would be appreciated as this is driving me mad. I'm considering putting my 2g tb back on just to test if the TB is for sure the problem but it is getting late tonight.

 

[->PrOjEcTGS<-]

So I just installed an evo3 IM and 1g TB, the car starts perfectly fine but then idles at 3200RPM. After a minute it settles down to about 2800 RPM and I'm at a loss for what is causing this.

A couple of things that are worth mentioning:

The throttle cable is slack and my throttle position according to the computer is .6%, the throttle plate also appears to be completely closed (I cannot close it more by turning it).

I do not have any coolant lines going to the bottom of the TB and I have not blocked off the FIAV.
The BISS is screwed all the way in.

I had to remove my EGR valve and I just looped the vacuum lines that went to the valve, should I have done something else?

My compressor was borrowed and did not come back with a tire chuch so I cannot BLT at the moment.


Any input would be appreciated as this is driving me mad. I'm considering putting my 2g tb back on just to test if the TB is for sure the problem but it is getting late tonight.

That is your problem right there. You need the coolant lines going to the FIAV if you do not have it blocked off. Otherwise it will never close and you will consistantly have a high idle.

 

[the_mork]

But should it really idle at 3200RPM even fully open? I've never experienced my car running this high even when it is very cold outside and I'm sure my coolant doesn't heat up fast enough to melt the pellet in the first 20 seconds.

I guess I'll try the coolant lines tomorrow and see how it goes. I was hoping to leave them off just for the sake of making it easier to alter my intake setup and keep intake temps down.

 

[the_mork]

I put my coolant lines back on and I did notice about a 400rpm drop but that still left me at 2600-2800RPM. I guess I'll try changing the ISC back to the 1g ISC, I used the one from my 2g(actually a RVR ISC but they are nearly the same) because I knew it was good. If that doesn't work then I'll put the entire 2g TB on, if that works then I'll swap the bottom ends around and see what I can do.

 

[->PrOjEcTGS<-]

But should it really idle at 3200RPM even fully open? I've never experienced my car running this high even when it is very cold outside and I'm sure my coolant doesn't heat up fast enough to melt the pellet in the first 20 seconds.

I guess I'll try the coolant lines tomorrow and see how it goes. I was hoping to leave them off just for the sake of making it easier to alter my intake setup and keep intake temps down.

Take a look at this post from RRE: http://www.dsmtuners.com/forums/bolt-tech/320799-my-solution-fiav.html#post151720501

Against what a lot of people think there is no "wax pellet" in the FIAV read through RRE's post and you'll understand how the FIAV works.

 

[->PrOjEcTGS<-]

Which TPS did you use when you swapped to the 1g TB? I believe the two are different. 1g's use a Idle Position Switch and the TPS to determine throttle position. On a 2g the TPS and IPS are one unit within the TPS. You will not use the IPS on the 1g TB except to adjust how far the TB plate closes.

 

[the_mork]

I used the 2g TPS. My impact driver broke so I didn't get a chance to do it tonight but I'll change the bottom ends of the TBs tomorrow. It is too much work to put the 2g throttle body back on just to take it off in a little bit. If I had new shaft seals I might put it on and keep it for a while yet but I was doing maintenance as well as an upgrade with this change.

I did not adjust the throttle stop but I shouldn't have to IIRC.

Before I rebuilt this TB I did let it soak upside down in a parts cleaner bucket just deep enough that the cleaner didn't reach the joint between the throttle body halves. I assumed that this would keep the delicate parts safe while giving me a clean looking TB. Are there delicate parts in the top half of the throttle body? I replaced the BISS because I thought that the cleaner might have damaged the o-ring but it didn't help.

 

[the_mork]

The problem was indeed with the throttle body though I can't tell you exactly what it was.

I used a vice grips and a drill to get all the screws out of the bottom and I replaced the entire bottom half of my 1g TB with the bottom half of an RVR throttle body (JDM mini van but the bottom half of the TB is exactly the same as a 2g) and everything became happy. My idle is a bit low not but I think that is because I need to adjust my BISS yet. I also forgot to hook coolant lines up to the TB to start with so besides getting a bunch of coolant on my garage floor I also tested my theory that the FIAV will not make you idle at 3K just because it isn't hooked up to coolant.