ta12sec

iTrader: (3)

Good morning gentlemen.
I have a swap vexhile using the engine and trans from a 2006 trailblazer ss. The only engine mods are cai with a Colorado style maf, cats removed, elecric fans added. I had the pcm and Tcm tuned by a well known tuner via mail tune.
The truck starts and runs, it revs in park/neutral.
if you put it in gear and touch the gas pedal it will idle up to 1800-2000 rpm and you have to stand on the brakes to keep the truck from taking off. If you hit the gas pedal harder it will rev to 2500+ and idle there and I have to push the brake pedal through the floor to stop the truck. After the truck is complety stopped for 10 seconds the idle will drop below 1000 but it's still 700-800. The tuner says I need to drive it for a few miles to remedy this. I drive it slowly around the parking lot, but on the street this thing doesn' stop as the brakes are fighting the engine.. is this a tune issue or do I need to be looking at something else? No engine light no faults stored.
Thank you for any thoughts or suggestions.

JoeNova

Sounds like the tune.

thompson

iTrader: (4)

Sounds like it is in the tune or IAC sticking.Have you tried to pull and clean the IAC? They build up oil from the terrible PCV system on the TBSS and will stick badly at times.

moehorsepower

iTrader: (3)

if you snap the throttle will the idle go down? T/B not sticking?

Floorman279

iTrader: (11)

Do u have a scanner that can read the tps sensor.....what % open it is at idle

ta12sec

iTrader: (3)

Looked at the tbody, it was clean but I cleaned it anyway. It has free movement open and closes fully. Snapping the throttle does not change the idle speed. In park and neutral snapping the throttle will rev and return to idle at 700 rpm. In gear snapping the throttle it will stay at 2500+ until the truck is completly stopped for 10-15 seconds.
I do have a scanner that can read the tbody position I'll bring it home tonight.

Jenson

iTrader: (32)

Have you tried the relearn process for the TB?

ta12sec

iTrader: (3)

Relearned t body with 3 minute idle, 1 minute key off 3 minute idle. Is that the correct method for this engine?

Ed Wright

iTrader: (1)

If the TPS shows anything but zero throttle angle on the scan tool, it will not idle down. 1% TPS will not idle down.

Jenson

iTrader: (32)

Yes. Some of the in gear airflow or follower airflow numbers must be off. It sort of sounds like its doing what a manual does while you are in gear. When you pull an E-TB M6 car out of gear it will idle down slowly like you are describing. Not quite 15 seconds, but not immediately either.

Floorman279

iTrader: (11)

that is not the relearn for our cars. search for it and you will find it. i did the relearn multiple times on mine and kept coming up with 5%. i looked real close and noticed the blade was in fact open. i lengthend the cable from that fancy black clip box thing and presto, fixed that issue.

Jenson

iTrader: (32)

I assume swap vehicle with engine/trans from TBSS meant he is using a TBSS throttle body.

ta12sec

iTrader: (3)

Truck has the tbss engine and trans and throttle body. The only thing changed between stock tbss is the cai with Colorado maf, electric fans and no cats.

Jenson

iTrader: (32)

So yes, you have an E-TB. No cable involved. The TBSS is the dumb one with the IACV still if I remember right. Sounds like an airflow number in the tune, it should get better with driving it around but that could lead to an accident. First 3 places I would look at are to much airflow added in the E-fan table, or to much left in the idle airflow in gear, or the MAF air flow is all jacked up. You can unplug the MAF and see if it changes anything to eliminate one issue

Madellous

I would take a look at the throttle cracker/follower and base running airflow. If it is returning to normal idle in P/N then it sounds like you have too much airflow in gear. What is TPS voltage showing?

ta12sec

iTrader: (3)

Spoke to my tuner, they advised me it could be a problem with my Colorado maf sensor and recommnded me changing to a ls7 maf. I bought ls7 maf and installed and had them retune for the maf. Installed in truck and it idles normal till warm then shoots to 2500 rpm. Hitting the gas will idle down for 2 seconds then back to 2500 rpm. Haven' tried to drive it. This was a running driving setup out of my tbss, the only reason I did tuning was the Efans

Ed Wright

iTrader: (1)

ta12sec

iTrader: (3)

I agree it is not physically the Maf sensor, I have to believe it's in the Tune. Since my last post i have swapped the tuners fender intake with ls7 maf, my home made cai with 4 in Colorado maf and the factory tbss maf sensor. All 3 intakes at idle in park rpm is < 2000 once warm. I replaced the tbody with a new gm one. And I smoke tested the intake no leaks., I have to belive this is something in the Tune.

Lsxford

iTrader: (6)

Sounds like a new LOCAL tuner is in order. I can't see it going from perfectly fine in the tbss to doing this now. If there was a hard fault the pcm would show it, you can't even fart down the intake of a newer car without setting a dtc (you may can I'm just saying they are sensitive). However a simple ETB reset with a scan tool could fix it, but usually this will idle high no matter the gear selection.