Bogging down at WOT in 2nd gear

[Redog]

WTF.

For some reason, even with this problem I went 3 rounds yesterday :eek:

At WOT, the car bogs down at high RPM's but only in 2nd gear.

1st time: @ 3850 rpms
2nd time: @ 4200 rpms
3rd time: @ 5100 rpms
4th time: @ 4500 rpms
5th time: @ 3700 rpms

The 5th time it never recovered, it was like I was hitting the brakes and then the gas. It got to 6000 rpms just fine in 1st gear, after the bog (I have to get off it and florr it again and it was fine thru the rest of the powerband) it shifted fine into 3rd gear at the correct shift point (around 5300 rpms. My 1/8 mile time was normal at 9.980 @ 71

What could it be? I read that there is another sensor on top of the TB that tells the TPS how open the throttle plate is, if this goes, the PCM goes crazy and bogs the car down thinking the throttle plate slammed shut.

Injectors?

fuel pressure?

Fuel filter was changed in March (at inspection I get it done, my inspection is in May, but I can get it done upto 90 days before the exp date)

Fuel pump is 2 years old

running a 1/4 tank of gas when this happened

[[ion] C2]

Sucks not having a wideband... (and a datalogging program like HPTuners) you don't know if it's too much fuel, too little, or how the graph is moving when this happens. Or how any of the sensors are reading.

Hard to diagnose exactly without the above tools available.

[RisenequinoX]

is there anyway to tell that the tb is actually opening??

[Redog]

It's open, the cables are fine

[Alerosaint]

possibly a tranny issue????

[Redog]

I thought that too, but never have a problem on accel and it's not happening at a shift point.

Plus if it was the tranny, the engine would keep revving to the limiter and be slowing down, that's not happening

[Nate's Alero]

sounds like the TPS, go ahead and swap it, maybe if you know someone at AZ or AAP, they would let you take a sensor out, and try it

[Redog]

^^ You think?

IDK I just had it replaced 18 months ago, but then again driving home the thottle response seemed mushy.

My mech will scan it, I'm sure. I'm getting a new tie rod put on tomorrow ;)

[Nate's Alero]

^^ You think?

IDK I just had it replaced 18 months ago, but then again driving home the thottle response seemed mushy.

My mech will scan it, I'm sure. I'm getting a new tie rod put on tomorrow ;)

im almost 100% sure its the TPS, clean your TB first, and your IAC port and sensor, and .....clean the entire intake...:lol:

[mfuller]

Scan it. Could be pulling timing due to KR, or perhaps torque management is rearing it's ugly head.

[Nate's Alero]

Scan it. Could be pulling timing due to KR, or perhaps torque management is rearing it's ugly head.

torque management?

[[ion] C2]

It limits the amount of torque the engine makes and is transferred to the transmission. Mine's turned off, as is Abuse Mode (tells if you're beating on it and tries to limit your power).

[Nate's Alero]

C2;478728']It limits the amount of torque the engine makes and is transferred to the transmission. Mine's turned off, as is Abuse Mode (tells if you're beating on it and tries to limit your power).

so thats like, when i notice my ho going slower, when i go on one of those in town rampages, trying to make it through stoplights and such, pretty much constantly WOT'ting? i feel it lose power..

[Redog]

Scan it. Could be pulling timing due to KR, or perhaps torque management is rearing it's ugly head.


KR? :ninja:

[mfuller]

KR? :ninja:
Knock Retard......basically the pre-cursor to detonation (which makes holes in your pistons).

[Redog]

O crap!

Welll if there;s a problem like that, wouldn't that trigger a code, even if it one of those that don't bring up a SES right away

[[ion] C2]

Unlikely, but it would be something pertaining to what's causing the knock. I logged a lot of knock during tuning my various setups, but nothing ever triggered a code. You can see the areas where there's significant amounts of knock retard.
Looking through our DTC lists it doesn't look like anything relevant would show up if too much knock is detected. Most codes that would be in any way relevant to having knock retard seem to deal with closed loop performance, which wouldn't be at WOT.

[Redog]

Ever since I filled up, I haven't had the problem

I was running a bit low on gas, so I put in $2 to get me thru the day on top of the 1/4 tank I had already.

I drove 18 miles from the track, plus the racing, took the long way home, and stopped for gas. Hasn't happened since.

Had the car upto almost 6 grand in 2nd (shifted at 5800 or 5900) :eek:

[[ion] C2]

Fuel filter or pump, but since you've already replaced those, who knows.

[AleroB888]

^^ You think?

IDK I just had it replaced 18 months ago, but then again driving home the thottle response seemed mushy.

My mech will scan it, I'm sure. I'm getting a new tie rod put on tomorrow ;)

I had a TPS fail completely at the track, eventually it went into a limp-home mode and the PCM defaulted to a fixed TPS value it decided upon. Mushy as hell on the drive home.

[GA_turbo]

I was going to say clean your MAF, but i guess is running fine now.