Look what followed me home:

Shaun41178(2) · Post by **Shaun41178(2)** » Fri May 23, 2008 10:30 pm

check to make sure the iac tube that runs to the lower intake manifold is plugged into your tb.

Chris-Nelson · Post by **Chris-Nelson** » Fri May 23, 2008 11:25 pm

does anyone have pictures of that vacuum connection?

Aaron · Post by **Aaron** » Fri May 23, 2008 11:30 pm

Idle at 3k = vacuum leak. Forget the brake booster line? Something of the like.

Flames out the exhaust means rich. 24# injectors with no tune and a single wire O2 will do that.

Chris-Nelson · Post by **Chris-Nelson** » Sat May 24, 2008 12:28 am

Yea, maybe I should get my exhaust finished so I can play with the wideband setup to see what is actually happening...

lucky · Post by **lucky** » Sat May 24, 2008 12:48 am

Chris-Nelson wrote:does anyone have pictures of that vacuum connection?

I don't but you kinda do..
the tube at the top of this pic..

connects to the stock TB via steel line and rubber coupling at the 1/2" port that is below the neck of the plenum.
I don't know what port that corresponds to on the TDC TB.

Series8217 · Post by **Series8217** » Sat May 24, 2008 2:28 pm

Shaun41178(2) wrote:check to make sure the iac tube that runs to the lower intake manifold is plugged into your tb.

He has a 3.4 DOHC TB. He needs to make sure that port on the lower intake is blocked off.

Chris-Nelson · Post by **Chris-Nelson** » Sat May 24, 2008 11:23 pm

I figured it out. Here is an image of my intake setup using the 3.4 TDC throttle body:

I believe that the vacuum port on the right side of the TB ( "L" Shaped) is for the IACV.

I plumbed the large LIM Vacuum port there before, but when I disassembled the intakes I found that my vacuum lines were kinked. I've reworked it now and that problem is fixed, but I'm still fighting a funny glowing manifold condition.

This next week I'll get the exhaust finished so I can plug in my Wideband O2 setup to begin tuning.

Series8217 · Post by **Series8217** » Sun May 25, 2008 12:09 am

Dude, no. The IAC doesn't have an external port. It's all internal. It just bypasses the throttle blade. You need to block off the port on your LIM. The L shaped one is for PCV.

The Dark Side of Will · Sun May 25, 2008 8:54 am

Yes, just put a heater cap on the lower manifold port.

Or unscrew the barb and replace it with a pipe plug.

Chris-Nelson · Post by **Chris-Nelson** » Sun Jun 01, 2008 12:37 am

How does this happen:

When running really rich? I thought this was something to see when running lean? Maybe I'm just wrong...

Aaron · Post by **Aaron** » Sun Jun 01, 2008 1:21 am

Are you sure it's running rich?

It's possible, that it is rich enough that raw fuel is getting left unburned, and pushed into the exhaust manifolds, then ignites and flames out through the exhaust manifold. It'll spool a turbo damn fast. But I highly doubt the exhaust components can get hot enough to do this, normally you need to retard your ignition timing a lot for this to happen, so it ignites the fuel as the exhaust valve is opening. Also, that is pretty far out in the manifold for it to be happening.

Shaun41178(2) · Post by **Shaun41178(2)** » Sun Jun 01, 2008 1:55 am

you have a normal idle or is it still really high? It should be aruond 1500 cold and 1k hot.

Glowing manifolds is usually a cause from a vacuum leak.

The Dark Side of Will · Sun Jun 01, 2008 10:18 am

Shaun41178(2) wrote:Glowing manifolds is usually a cause from [the LEAN condition stemming from] a vacuum leak.

Chris-Nelson · Post by **Chris-Nelson** » Sun Jun 01, 2008 11:05 am

My idle is still really high - like 2,500 rpm but it eventually drops down to around 1,300 or so.

My wideband says that I am running really rich and it spits out black smoke sometimes when I am trying to start it.

My fuel pressure sits around 45psi all the time and as it is running it backfires every once in a while - sounds like fuel igniting in the muffler...

I'm having a hard time getting the timing set perfect because when I put it into diagnostic mode the idle is a lot lower and it doesn't want to stay running.

I'm hoping that darth fiero can make some adjustments on my chip so that it will run a little better right off the bat.

fieroguru · Post by **fieroguru** » Sun Jun 01, 2008 11:27 am

Chris-Nelson wrote:
I'm having a hard time getting the timing set perfect because when I put it into diagnostic mode the idle is a lot lower and it doesn't want to stay running.

You need to get the baseline timing set right and to do that it must stay running. Crank open the throttle blade (might need to remove the plug for the adjuster screw) so it will stay running. Once it wil stay running, check the timing and make the needed adjustments. Once the timing is set right, then you can bottom out the IAC to set the minimum idle speed (you will find the vacuum leak during this stage if it is present) and lastly adjust the TPS (if it is adjustable).

Shaun41178(2) · Post by **Shaun41178(2)** » Sun Jun 01, 2008 11:39 am

you need to get the vacuum leak fixed first. 2500 rpm is too high when cold. It should be around 1500. Make sure your tb is closing all the way. it might be getting hung open.

SPray some carb cleaner around your vacuum lines and your intake gaskets. See if the idle changes.

If all else fails start plugging vacuum ports at the intake manifold. You don't need egr or cruise or anything other then the map sensor to set the timing or have it idling in your driveway.

I have never ever had to play with the iac screw on the tb on my setups. on a properly running setup you shouldn't need to do this. The fact that its being suggested means you have a problem.

Find the vacuum leak first, then work on the timing.

On my turbo setup I have all my vacuum ports plugged in my intake except for the map sensor.

You have 24 lb injectors right? Too big I think for your setup. 19's would have been better. That might be why the wideband is reading rich at startup. How rich is rich by the way? Mine is like in the 13's when starting cold.

Series8217 · Post by **Series8217** » Sun Jun 01, 2008 9:28 pm

You did plug the port in the lower manifold, right? Also make sure the CSI port is plugged or whatever.

Chris-Nelson · Post by **Chris-Nelson** » Sun Jun 01, 2008 9:30 pm

Tomorrow I am going to work on this thing again and go to town with capping off all unnecessary vac ports and using some carb cleaner to check for leaks.

One last piece of clarification however. This is how I have my UIM and LIM connected as far as vacuum lines go:

Does it really matter that it is the PCV vacuum port at the TB? Is this a bad way to have it set up?

The reason that I believe this was the proper method of installation is because it is practically identical to how the factory upper manifold - lower manifold vacuum hookup is done, except on the OEM piece, it is on the bottom side.

Right now I have the PCV hooked up to the same large vac line as the power brake vac line with a "T".

If this is wrong, someone please explain why so I can learn.

Thanks.

Chris-Nelson · Post by **Chris-Nelson** » Sun Jun 01, 2008 9:48 pm

This 4 minute long video is the first testing/diagnosis video that I have put together for Mr. Ryan Gick of Sinister Performance so that we can figure out the custom tune for my car:

http://videos.streetfire.net/video/Fier ... 164161.htm

FormulaGT · Post by **FormulaGT** » Mon Jun 02, 2008 3:52 am

Why do you sit there and let the car idle at a stupid high 2600 rpm until the manifolds glow? If it runs that high, turn the fuckin car off and fix the god damn vacuum leak, dont let it continue running like that.

I suggest pulling the plenum and using the black, high temp rtv on the EGR port. The gasket didnt seal for me, resulting in a very high idle similar to yours. Put a thin layer on the plenum and the block off plate (assuming thats what is used) and sandwich the gasket between them.

FP seems high, should be 35. Once you fix the leak, that may drop back down tho.

Have fun :thumbleft:

Edit to say - That aftermarket TB is the first place I would look. It may not even be properly installed, or something is fubar with it. Try blocking off the TB with a flat piece of cardboard, you want to see if the car will run with it blocked off.