Kenny_k82

2001 GT 5spd, I put an aftermarket TB/plenum on it. Used new gaskets and gasket maker, it is sealed well... I can find no vacuum leaks. When I get to say 1800 rpm's between shifts and push in the clutch to shift it will hang at whatever rpm's I had the car at before I pushed clutch. Also if I'm at say 1000 rpm's and put my car in neutral it jumps and hangs at 1200-1400 rpm's until the car comes to a stop. I have no idea what the problem is... should I clean the IAC? I had heard about cutting an aluminum can to make a space between the IAC and the plenum. Any idea's?

Nestang

I had/have the same problem with my 04 GT 5-speed, Ive cleaned the IAC and it usually helps, and have also done what your talking with the can except made it with 1/8 aluminum and i forget what size whole to drill in it, it seems to work well but still acts up every now and again, I think its just the IAC sticking.

WannaBeGearHead

Nestang, where in NE are you? Kenny and I are both in Lincoln.

Nestang

Im wayyy on the west end of the state near Sidney, I come down to Lincoln every once and awhile though, been thinking of moving there actually.

.boB

It didn't do that before you installed the new parts. So it must be a problem with the new parts, the installation, or the integration of the old and new parts.

Sounds like a problem with the throttle linkage. Disconnect everything up to the new TB. By hand, hold it at 2K prm or so. Then lightly release. If it returns to idle normally, the problem is not the TB.

Now start putting everything back on, and repeat the test every time you add something.

cliffyk

Did you disconnect the battery for 5-7 minutes after installing the TB/plenum? Doing so will clear the KAM (Keep Alive Memory) and force the PCM to relearn to idle air trim and other IAC related values.

Also, I have seen many after market TBs that did not have the throttle stop screw (it's not an idle adjust screw) properly adjusted--here is the process for doing so...

Nestang

Actually bob I had this problem before hand as well, I'm not sure if he did and its not the linkage or nothing like that, Ive checked and checked and it always seems to come back to that IAC valve, I like to clean it and the MAF every once and awhile, But its only acted up maybe once since I made that plate, I dont know we'll see how well it works once it starts warming

Kenny_k82

I'll wait till it gets warm, I need to see how to make that little plate out of a can. I will clean the maf and iac with some carb cleaner too and see what happens. Just need to find my article about doing the iac thing again.

Nestang

Well if you cant find the specs just let me know and Ill pull mine and take some pics and check the hole size, its only 2 bolts anyway

cliffyk

Just get a 1/2" copper pipe cap and drill a hole in it--start with a 17/64" or so bit. Insert the pipe cap into the IAC intake tube and see how it behaves.

If it wants to stall on deceleration open up the hole in 1/64" increments.

I made an aluminum insert, but only because I have a small lathe, the pipe cap will work just as well and is a heck of a lot easier to fiddle with than making gaskets/plates.