My 05 Envoy has no ballz. 0-60 times horrible!

[CaptainXL]

Hello everyone. I've been having an issue with my 05 envoy xl I guess since the day I got it. When I get on the highway from a dead stop my 0-60 time is around 14 seconds. I see many ext and xl models on YouTube putting up 7, 8 or even 9 second times. I recently unhooked my exhaust and for those of you who have been following my stories know that I have done complete up to date maintenance on this thing with no better performance. Accordingly this truck should be pulling twice as hard as it has been . My calculated flywheel hp is 130 which is not right. I have no check engine light and no history of one either. For all intents and purposes my truck runs fine. It's just when I go to floor it. There js really only one item noteworthy that might be the problem. When I hook my scantool up and use torque to see my throttle position it max's out at about 80%. If you have any ideas please let me know. Just about at my limits troubleshooting this thing! Thanks.

 

[Boricua SS]

by unhooking your exhaust do you mean the resonator delete, and/or muffler swap? this happened on my DD (2001 Grand Prix GT), where i was getting nowhere when mashing the pedal... turned out to be a clogged cat.. keeping rpms under 2-3000 the car would move just fine and keep up with traffic.. but when i mashed it, or tried to get over 3000 rpm's, she just fell on her face and just wouldnt move... maybe thats something you can look at if you haven't already.. but then again, you said that this has been going on since you bought the truck.. so maybe not a cat issue..

and are those XL's tuned on youtube? or just bone stock?

 

[Ilikemy3s]

IF you are trying ot mash the pedal to the floor as fast and hard as you can, I dont think the PCM tune will let the engine rev like that. Remember our trucks are drie by wire .. there is not cable from the pedal to the throttle body. Try a gradual but steady pess of the pedal and see how that works. At least that is what I have to do. Just my 2 cents

 

[SAR85]

Another thing to consider is if you have any floor matt(s) and its thickness, which may prevent complete depression of the pedal.

 

[Boricua SS]

IF you are trying ot mash the pedal to the floor as fast and hard as you can, I dont think the PCM tune will let the engine rev like that.

i have to disagree with that... this is directly from pcm's website...

Our performance tuning for the 4.2L I6 typically yields 10-14hp and 1-3mpg, as well as better part throttle response, driveability, and more pep off the line. Our tuning also helps with towing if you choose to do so. We can account for any modifications you might have (NO speedo corrections on 02-05, sorry!). After placing your order, please click on "ordersheet" and fill out an ordersheet for your vehicle. We can service all variations of the Trailblazer, including Envoy, Bravada, Rainier, and Ascender...

i had one (tune) in my SS until i spun a bearing.. and with the tune and e-fans, it shaved over a full second off of my times.. and how i would launch is straight from idle, mashing the pedal... yes i know other factors apply, like rear gears, etc... but the tune does clean up throttle response..

 

[Ilikemy3s]

I dont recall him saying he had the PCM tuned .. so I took it as being stock ...

 

[CaptainXL]

Another thing to consider is if you have any floor matt(s) and its thickness, which may prevent complete depression of the pedal.

Removed mat and now showing 85% wot with koeo. Thanks for the tip. Took it out for a test and no improvement.

I dont recall him saying he had the PCM tuned .. so I took it as being stock ...

Yep I have stock 4.2

by unhooking your exhaust do you mean the resonator delete, and/or muffler swap? this happened on my DD (2001 Grand Prix GT), where i was getting nowhere when mashing the pedal... turned out to be a clogged cat.. keeping rpms under 2-3000 the car would move just fine and keep up with traffic.. but when i mashed it, or tried to get over 3000 rpm's, she just fell on her face and just wouldnt move... maybe thats something you can look at if you haven't already.. but then again, you said that this has been going on since you bought the truck.. so maybe not a cat issue..

and are those XL's tuned on youtube? or just bone stock?

The couple ext I looked at are stock. 9 seconds for the both of them. I recently removed my cat from the manifold to see if that was the hangup but it didn't make much difference. Despite the wwii tank sound i still had crapy times.

Here's a video I took. Notice how unsmooth the accell is and how long it takes to get from 50-60. As you can see rpms are good.

[video]http://m.youtube.com/watch?v=3KnQkr0aFhA[/video]

 

[Sputnik312]

Damn... Hopefully roadie will chim in sometime soon

 

[The_Roadie]

I got nothin'

 

[03TB93]

dang man.. how many miles are on the voy and how long have you had it? did you buy it new? im just thinking an throwing it out there but maybe cleaning your air filter/throttle body. Again, just throwing ideas out but maybe your air/fuel mixture messed up and the engine isnt getting what it needs? other than that im not sure..

 

[Wooluf1952]

Sorry if I missed it, but, is it possible the fuel pump is worn and not keeping up?

 

[CaptainXL]

Sorry if I missed it, but, is it possible the fuel pump is worn and not keeping up?

That's what I was thinking would be the next thing to check. I'm gonna test volume by dumping some fuel into a gallon jug and see if the volume is OK. I tested the pressure and its good.

 

[Heavyblaze]

You can floor it to all the power from a almost dead stop the torque mangement from the computer won't give you all the power at once so it won't damge the drivetrain.

 

[Sparky]

You can floor it to all the power from a almost dead stop the torque mangement from the computer won't give you all the power at once so it won't damge the drivetrain.

It should still pick up after a short bit though. Mine does. I have the SWB but still is similar enough. Start off a little slow then pick up and scoot.

Maybe there is a torque converter issue, letting the RPMs come up but not transferring power through to the transmission and rest of the power train? Just a random thought.

 

[pennywise]

Doing an acceleration test with the trans in 3 might rule out the transmission or TC. Not full proof though. Look at the parking brake it might not be releasing properly. The fuel pressure regulator may not be working properly. They can work at idle but not open under load, which is pretty hard to trouble shoot. If you can check the air fuel ratio with the vehicle under load that would be the easiest way to rule out the FPR. It should be around 14.2:1 with no load and drop under acceleration.

 

[Sparky]

Not following you how putting the trans in 3rd would rule out the TC. Power still has to go through the TC to get to the trans.

There isn't a whole lot that can go wrong with a TC but they can fail.

 

[Wooluf1952]

Doing an acceleration test with the trans in 3 might rule out the transmission or TC. Not full proof though. Look at the parking brake it might not be releasing properly. The fuel pressure regulator may not be working properly. They can work at idle but not open under load, which is pretty hard to trouble shoot. If you can check the air fuel ratio with the vehicle under load that would be the easiest way to rule out the FPR. It should be around 14.2:1 with no load and drop under acceleration.

IIRC, the 2005 and newer, don't have fuel pressure regulators.

 

[seanpooh]

I'll time my XL tomorrow and tell you my 0-60 mph time.

I have a KN intake, ported TB, straight catback, shiftkit and upgraded servo tranny, 265/65R17 rear tires (stock front) and full tank of gas. I think thats all my mods that I can remember now which should make a slight difference.

 

[jimmyjam]

IIRC, the 2005 and newer, don't have fuel pressure regulators.

every car has one, they just moved it into the gas tank

 

[pennywise]

The FPR is on the sender assembly. It is a spring and diaphram, not vacuum. It is controlled by a pressure balance across the diaphram. The pressure stays constant as long as the diaphram and spring are in good working order.

 

[pennywise]

Not following you how putting the trans in 3rd would rule out the TC. Power still has to go through the TC to get to the trans.

There isn't a whole lot that can go wrong with a TC but they can fail.

Yeah it's not full proof but it's worth a shot. I'd try it.

 

[Phantom]

I just timed Phantom and ours was between 10 to 11 secs. Tami is gonna post the video as it was taken on her phone and my comp doesn't have bluetooth. we had all the kids in the truck as well all four of em.

 

[Voymom]

Not to rub it in any....But here is my baby Phantom going from 0-60. Took him about 10-11 seconds.

Spoiler

Not enough power for me, but don't tell Phantom

03 Envoy 0-60 - YouTube

 

[Wooluf1952]

every car has one, they just moved it into the gas tank

The FPR is on the sender assembly. It is a spring and diaphram, not vacuum. It is controlled by a pressure balance across the diaphram. The pressure stays constant as long as the diaphram and spring are in good working order.

Good to know. I thought when they moved the filter into the tank in the 2005 and deleted the FPR from the engine compartment, it was eliminated.
Is the FPR replaceable? Or do you have to replace the pump?

 

[Heavyblaze]

If give it about 1/2 to 3/4 throttle the computer won't take as much power way it well make it go like crazy.When I give my 1/2 to 3/4 throttle my seems to pull alot harder then when you floor it.I got by a 4 cyl. tracker by flooring it.

 

[CaptainXL]

Wow. Ok, let me start off by saying that I appreciate all of your serious support and kind comments. You know it's funny that all this time I thought everything was Ok with my truck as it ran pretty well. But as I can now see it looks like I have some issues to iron out.

Thank you for your comments. I will let you all know how its going. I think my next step is to look at my a/f ratio and see if I am getting enough fuel. It's just really mind boggling that I don't have any codes.

 

[seanpooh]

Just an update, 0-60 mph took me 14.3 seconds on a level road. We're in the same boat. I forgot to mention I have a PCM tune and everything in my driveline is working. 3.42 ratio and no locker. The EXT is just 2 1/2 tons too heavy.

 

[CaptainXL]

en something is amiss.

Just an update, 0-60 mph took me 14.3 seconds on a level road. We're in the same boat. I forgot to mention I have a PCM tune and everything in my driveline is working. 3.42 ratio and no locker. The EXT is just 2 1/2 tons too heavy.

Thanks for the run. I don't think weight is the whole story. As you can see others get 11 seconds or better. I would say unless this is due to the fact that we have the 3.42 gears then something is alluding us.

Not to rub it in any....But here is my baby Phantom going from 0-60. Took him about 10-11 seconds.

What final drive ratio do you have?

 

[Sparky]

I know I have the SWB but would it help if I did a timed 0-60 run? My TB is stock with the same 3.42 gears. Actually I have the 8.6" now in mine (same as the EXT), so that would even be the same in case that slight bit of weight difference actually makes a difference.

 

[Voymom]

What final drive ratio do you have?

I have the 3.73 with the locker. I am 100% stock, no performance mods at all, plus a really bad fan clutch. I was on level road, stock height, tires, rims...everything stock. Plus it was loaded down with 4 kids, me the hubby, and gear like car seats, stroller and emergency kits.

I'm stupid, so I'm not sure if the gears are what you meant by drive ratio. Maybe the hubby can chime in when he is home, in case I got the drive ratio mixed up with the gear ratio.

 

[CaptainXL]

I have the 3.73 with the locker. I am 100% stock, no performance mods at all, plus a really bad fan clutch. I was on level road, stock height, tires, rims...everything stock. Plus it was loaded down with 4 kids, me the hubby, and gear like car seats, stroller and emergency kits.

I'm stupid, so I'm not sure if the gears are what you meant by drive ratio. Maybe the hubby can chime in when he is home, in case I got the drive ratio mixed up with the gear ratio.

Your good. 3.73 is the number I was looking for. Thanks.

I know I have the SWB but would it help if I did a timed 0-60 run? My TB is stock with the same 3.42 gears. Actually I have the 8.6" now in mine (same as the EXT), so that would even be the same in case that slight bit of weight difference actually makes a difference.

Sure. That might help. All things being equal in power im guessing you might be around 12 secs due to less weight.

 

[Sparky]

Alright I'll do that. Were you completely flooring it or just 75% throttle? I don't know the last time I went 100% WOT in any of my cars (yeah, even the Camaro).

 

[CaptainXL]

Alright I'll do that. Were you completely flooring it or just 75% throttle? I don't know the last time I went 100% WOT in any of my cars (yeah, even the Camaro).

Yes please. Actually floored is about 85% throttle according to my scan tool so your not actually flooring it even if you press the pedal all the way down.

 

[RZAwora]

Alright I'll do that. Were you completely flooring it or just 75% throttle? I don't know the last time I went 100% WOT in any of my cars (yeah, even the Camaro).

I'm with you there Sparky. I haven't "floored" any of my vehicles since my first car. IMO it's just not good for the motor and trans. Wish you luck in getting this thing figure out CaptainXL. I hope it isn't anything major.

 

[CaptainXL]

I'm with you there Sparky. I haven't "floored" any of my vehicles since my first car. IMO it's just not good for the motor and trans. Wish you luck in getting this thing figure out CaptainXL. I hope it isn't anything major.

Thanks for the words of encouragment.

I found another video on youtube where an 06 LWB is showing a 9 second 0-60. The truck shifts into 2nd at 50 mph so that means he has a 3.42 rear axle if I am not mistaken.

[video=youtube;aR9g1QN0jmg]http://www.youtube.com/watch?v=aR9g1QN0jmg[/video]

 

[Pittdawg]

I'm with you there Sparky. I haven't "floored" any of my vehicles since my first car. IMO it's just not good for the motor and trans. Wish you luck in getting this thing figure out CaptainXL. I hope it isn't anything major.

I floor it all the time...it helps in finding the weak components that need replacement

 

[Sparky]

Well today my first opportunity I forgot to do it, then it rained and I wasn't going to floor it in the rain. Back end gets a little happy when doing that.

 

[mubai]

I'm flooring mine tomorrow, this is the only contribution I can make.

 

[WarGawd]

Thanks for the words of encouragment.

I found another video on youtube where an 06 LWB is showing a 9 second 0-60. The truck shifts into 2nd at 50 mph so that means he has a 3.42 rear axle if I am not mistaken.

Well I was bothered a bit by some of the feedback and times reported by some of the others in this thread so I am glad you found that video because it directly supports my own observations. While doing some testing the other day to make recordings to post for help with what I thought was a tranny whine, I did a series of runs to observe the sound under a variety of conditions. At the end I did a WOT run on a flat straight back road at around 4AM, from 0-145km/h (0-90mph). I have the 3.42 rear end, tranny shifted flawlessly and smooth at 6100 rpm/86km/h (53mph) at the 6.875s mark (waveform analysis of the audio file let me pinpoint the shift time pretty exactly). Since it was an audio recording, I don't have another "landmark" to time the exact spot where it hit 60 mph, (96.6 km/h) but there's no way it was 4 seconds more...subjectively I would say it was 2s max putting me at a 0-60 time of right around 9s.

I continued to hold WOT until the second shift point which happened at the 23.3s mark at 145km/h (90mph), but by that point I lost my balls and let off the throttle since this backroad has a 60km/h limit and I REALLY didn't wanna see any cops. Even .zip'd the file exceeds allowable forum limits, but if you want to hear it (anyone) lemme know and we'll figure out a way.

FYI I should mention this is completely stock configuration (except CAF ) TB cleaned about 6 weeks ago, air filter is nearly new, plugs have not been changed yet (have them ready to go but no time), truck has 175k km on it, and I was carrying about 200lbs of tools, cleaning supplies, water, cooler, fishing tackle and rods, 5 kids roller blades and several car seats at the time of the test.

Cheers
WarGawd

PS - the guy who did the video has the same whine as I do, are they all like that cuz I honestly don't know what's "normal" for these

 

[Voymom]

Well I was bothered a bit by some of the feedback and times reported by some of the others in this thread so I am glad you found that video because it directly supports my own observations. While doing some testing the other day to make recordings to post for help with what I thought was a tranny whine, I did a series of runs to observe the sound under a variety of conditions. At the end I did a WOT run on a flat straight back road at around 4AM, from 0-145km/h (0-90mph). I have the 3.42 rear end, tranny shifted flawlessly and smooth at 6100 rpm/86km/h (53mph) at the 6.875s mark (waveform analysis of the audio file let me pinpoint the shift time pretty exactly). Since it was an audio recording, I don't have another "landmark" to time the exact spot where it hit 60 mph, (96.6 km/h) but there's no way it was 4 seconds more...subjectively I would say it was 2s max putting me at a 0-60 time of right around 9s.

I continued to hold WOT until the second shift point which happened at the 23.3s mark at 145km/h (90mph), but by that point I lost my balls and let off the throttle since this backroad has a 60km/h limit and I REALLY didn't wanna see any cops. Even .zip'd the file exceeds allowable forum limits, but if you want to hear it (anyone) lemme know and we'll figure out a way.

FYI I should mention this is completely stock configuration (except CAF ) TB cleaned about 6 weeks ago, air filter is nearly new, plugs have not been changed yet (have them ready to go but no time), truck has 175k km on it, and I was carrying about 200lbs of tools, cleaning supplies, water, cooler, fishing tackle and rods, 5 kids roller blades and several car seats at the time of the test.

Cheers
WarGawd

PS - the guy who did the video has the same whine as I do, are they all like that cuz I honestly don't know what's "normal" for these

First I just want to say that I am not calling you a liar, or assuming that you didn't hit 90mph in 23 seconds, but from the sounds of this and your vehicle gear ratio being 3.42 and mine being a 3.73, I should be hitting 0-60 in like 7-8 seconds and I am running 10-11 second times. I'm just trying to find out wth the difference is in the gears, trucks, etc...I'm still new at this so just bear with me lol.

I know there are a TON of variables that can go into this, cargo, tires, ground level, ground surface, fuel amount etc...From what I have been reading in this thread alone, is that maybe all our trucks are fucked up lmao I know that with Phantom anyways, he can be sluggish on certain days, and during certain driving ways if that makes sense. Some days I can WOT and he flat out just takes off, and other days I just feel like I have to rock back and forth in my seat to get passed a damn Ford Escort.

This topic is extremely interesting to me, because if all of our PURE stock vehicles, that are made 100% identical mechanically are running different times, then there has to be some type of variable contributing to it. Or we all just need to get together and fix the issue to our slow poke trucks Anyways, I'm very interested to find a logical reason if there is one, as to why all of our mechanically identical trucks, run so differently?