Help!!! Engine wants to run full speed when at startup

[indiana818]

I have a 2002 2.5 n/a engine with wayne's ecu and harness
when i started the engine ,it wants to run at full speed no idle at all.
I changed the air idle control valve -- no help.
I have ordered a tps valve and it should be here in a few days.
Anyone have any suggestions as to what could cause this condition?
I have looked for air leaks but it is hard to when the engine runs
and i have to shut it off in about 2 seconds

[STiPWRD]

Are you saying the engine automatically revs up to red line when started? This is a dumb question but are you absolutely certain the throttle valve is closed? It's not drive by wire right?

[Jaime]

That's a cable throttle, right? If it really is running at full throttle then you need to find out how the air is getting in. The idle air control valve doesn't have the capacity to get you anywhere near full throttle.

[Quiny]

Did you do a TGV delete? maybe you forgot to block them off? I can't imagine that kind of rpm with the throttle plate shut. Hey at least it starts, that's progress.

[bompus]

I would assume you would need a good amount of air being supplied. If the throttle body is closed, the air must be coming from a large hole somewhere on the intake manifold between the throttle body and the the heads. For it to reach higher RPMs, I'd imagine it would be a good sized leak.

[Bob_n_Cincy]

When the engine starts up, it moves around a lot.
Make sure you have slack in your throttle cable, it may have been jerked.

Take the air box off the throttle body and check that the throttle butterfly is all the way closed.
Bob

[metalmaker12]

It has to be a large hole dude, or throttle flap is stuck open

[indiana818]

thanks for all the advise :
throttle is closed
not a wire setup
throttle cable is ok
i will look for leaks on thursday

[Quiny]

Maybe the vacuum source for the brake booster isn't plugged

[longislandwrx]

yeah or a freeze plug fell out.

[Turn In Concepts]

No freeze plugs on these engines. Has to be a large intake leak.

Tony

[longislandwrx]

I mean the "freeze plug like" plug in the intake manifold, I know they are not actual freeze plugs.

http://forums.nasioc.com/forums/showthread.php?t=2554165

http://forums.nasioc.com/forums/showthread.php?t=1350169

i'm sure there's a cool name for them.

[indiana818]

does anyone know the wire color of the iacv (6 wire type) for a 2002 impreza 2.5L n/a engine
it appears that there is no 12 V power to my iacv. i might try to hot wire it also.
here are the wire color #s 1. yellow 2. yellow 3. blu 4. grn blu 5 red yel 6. blu blk
thanks
kerry

[Quiny]

It gets power from the main relay, same as the injectors. If it runs then I would say your relay is working, must be a missing connection somewhere. I can send you the schematics if you PM or email. The 2 yellow are 12volt the rest go directly to the ECU

[indiana818]

thanks,

i would lov a diagram
my e mail is rimexlighting@yahoo.com

thanks again

[indiana818]

thanks for the email but my mac could not ID the file extension and let me open this file
do you have it in pdf ?
thanks ahed of time
'kerry

[Quiny]

I just sent off a PDF.

[Austexican]

Don't forget to check the tension on the throttle return spring. That was a problem on my Ford 302 V8.

[ssssly]

The iavc will only get you a few hundred RPM. Won't flow enough air to get you to redline.

Can just disconnect it to test.

Go to a cooking supply store and get a hand held smoker. Pull the return for the crank case return air off the turbo inlet and blow smoke into it to see if you have small leaks.

If that doesn't show anything, blow the smoke around the intake manifold and see if it gets sucked in anywhere.

[indiana818]

thanks ill try that idea

[tofer9458]

best way to check iacv is to eliminate iacv, remove it and lay a piece of thick cardboard across it. basically vacuum will pull it tight and seal it up.

if it idles its a iacv problem, if not vacuum problem