slowswap

Wow your stupid. When you rev match your downshifts like you should be, there is absolutely no wear on the clutch.

shawn672

i use gears to slow down and have never had this issue either

Joel

If the clutch is being used, then it is being worn. Why do you think you have to replace them eventually? Every time you engage and/or disengage the clutch it experiences a certain amount of friction, that is what makes it work. This friction is what causes the clutch to wear out eventually. It's science. So when you downshift while slowing down, regardless of how smoothly you're doing it, or how well you are "matching your downshifts," you are wearing the clutch.

Kodatech

+1

+2

+0.5

+1










Seriously though, I have seen MORE than a few ETBs get messed up from cleaning solution getting into the electronic parts of the TB. It is possible when you sprayed it, some of the cleaner dripped down the shaft that the blade is screwed to and dripped on to the motor, or the sensor in the ETB.

Joel

Well that's initially what I thought happened, which is why I bought a new TB. But after putting on the new TB, the problem remained the same. So now I know that the issue is not with the TB. I think the ECM isn't figuring out that it can change the idle position to account for the extra air flow provided by a clean TB.

Kodatech

How long have you been driving with the new throttle body?

Joel

3 Days. All three of those days included a 52 mile round trip commute to work.

flobeelicious

if you're seeing a sporadic idle after coasting down in gear, most likely its a control overshoot in the system. make sure that you're not dropping it below about 800. if you've kept the car in gear slowing down, the system has been cutting the fuel (if in the right conditions). as soon as the clutch is engaged, computer has to supply fuel to keep the engine running - hence the overshoot to 1500ish, and then a couple of bumps as it tries to correct for the overshoot. if you want that problem to go away, stage 2 is better than stock, but still not perfect.

as for the clutch wear, the clutch wears when its being slipped. when you're completely on or off the clutch, there is no wear going on. unless you're slipping the crap out of it trying to use engine braking to slow you down, it shouldn't be an issue.

Joel

I'm still trying to get this sorted out, I've been emailing back and forth with the dealer. I am thinking I just need a reflash. The guy at the dealer doesn't think that will fix it, he says he thinks it's the Idle Air Control Valve. But do Cobalts even have one of those? I didn't think that they did.

outtamymind

no the cobalts do not have an IAC valve. thats what i originally thought when mine started doing

pat_07ss

bump for a solution

I have the same issue after installing an LSJ TB

shawn672

you cant drop an lsj tb on this car without a tune, last i heard
you likely damaged the connector, these things are a pain to get off and if you force them off, you will break them
you need to pull the grey plastic back, then use a pin or small flathead and push down on the black plastic tab and then pull out at the same time
its a pain in the ass

pat_07ss

no that was easy, and I know its not damaged because when I reconnected my stock TB it worked

you don't need a tune with an LSJ TB on a 2.4

pat_07ss

guys we need to find a solution for this... I will ruin my clutch driving around like this

GXPFire

I think it's a matter of the ECM learing the throttle position at idle. I would have the codes cleared and see if the idle changes.

pat_07ss

what's the difference between clearing codes with a scanner and unplugging the battery?

umrdyldo

iTrader: (1)

Maybe a GM case relearn. Air Leak or throttle body connector is damaged. Im sure you have tried undoing the connector and reconnecting.

pat_07ss

CASE is for the crankshaft no?
I've done one of those after getting my ECM tuned by Vector already, and it cost me $50.
Why do you think a CASE relearn would help?

umrdyldo

iTrader: (1)

It probably won't do anything.

GXPFire

Unplugging the battery doesn't always clear codes, esp. on newer cars. Clearing the codes will for sure reset your fuel trims and whatnot.

Smiles

I wish I had read this before I cleaned my tb
mine is running at 2500rpm. Did anyone find a solution?

Joel

Nope. I'm still having the issue. I have yet to find anyone who's been able to fix it and give me a straight answer about how they fixed it. I'm still thinking a reflash is necessary, but I don't want to spend $100 to get it done unless I'm sure it will work.

Coblasts

Ive never had mine off yet but I have a few question to help come up with a solution.

1) when removing the throttle body is the plate closed or open and if open how far approx.

2)Does the throttle plate move freely to open it when cleaning or do you have to force it open with slight pressure.

3)Did any one try removing the motor that opens and closes it then clost the throttle plate all the way and reinstalling it.

4)What tell the pcm or ecm that the throttle plate is closed.

I have some info I will post to help ,maybe someone can use it to figure out whats happening.

Reference info;

Throttle Body Assembly
The throttle assembly contains the following components:

• The throttle blade

• The throttle actuator motor

• The throttle position (TP) sensor 1 and 2

The throttle body functions similar to a conventional throttle body with the following exceptions:

• An electric motor opens and closes the throttle valve.

• The throttle blade is spring loaded in both directions and the default position is slightly open.

• There are 2 individual TP sensors within the throttle body assembly.

The TP sensors are used to determine the throttle plate angle. The TP sensors provide the powertrain control module (PCM) with a signal voltage proportional to throttle plate movement. The TP sensor 1 signal voltage at closed throttle is near the 5-volt reference and decreases as the throttle plate is opened. The TP sensor 2 signal voltage at closed throttle is near the low reference and increases as the throttle plate is opened.

Normal operating mode

During the operation of the throttle actuator control (TAC) system, several modes or functions are considered normal. The following modes may be entered during normal operation:

• Minimum pedal value--At key-up the powertrain control module (PCM) updates the learned minimum pedal value.

• Minimum throttle position (TP) values--At key-up the PCM updates the learned minimum TP value. In order to learn the minimum TP value, the throttle blade is moved to the closed position.

• Ice break mode--If the throttle is not able to reach a predetermined minimum TP, the ice break mode is entered. During the ice break mode, the PCM commands the maximum pulse width several times to the throttle actuator motor in the closing direction.

• Battery saver mode--After a predetermined time without engine RPM, the PCM commands the battery saver mode. During the battery saver mode, the TAC module removes the voltage from the motor control circuits, which removes the current draw used to maintain the idle position and allows the throttle to return to the spring loaded default position.

Red07SSNA

1. Plate is not closed -- it is in a relaxed state and double spring loaded. When you turn off the engine the TB goes to a closed position and then releases after the engine stops. You can hear this if you listen closely.

2. No it is spring loaded both ways and needs to be pushed closed -- or open to clean. It will return to the relaxed state after pressure is released.

3. No...not a good idea -- calibrated probably.

4. TB plate position sensors -- what some of the wires go to.

majourpain

has anyone gone and had the DTC cleared. as mentioned before if you erase codes even if there is none you will reset the tables for fuel and i believe spark? to be honest it sounds like the PCM is stuck in the warm up cycle not sure but clearing the codes is often free so give it a shot GL