GrandAmGT.com Forum
http://www.pfyc.com GrandAmGT.com Premium Memership Signup
MilzyMotorsports.com   

Go Back   GrandAmGT.com Forum > GAGT - Technical - Sponsored by www.MilzyMotorSports.com > Technical Q&A

Reply
 
Thread Tools Display Modes
Old 03-30-2005, 07:13 PM   #1
slowassgtx
GAGT - Newbie
 
Join Date: Mar 2004
Location: syracuse
Posts: 6
Vehicle: 98 grand prix GTX
slowassgtx Gettin' there
car accelerates by itself?

Ok so this is my gf's 99 grand am Se and I havent had a chance to look at it yet. But here is what she said. The car will accelerate to 10 mph without her pressing the accelerator and keep doing it throughout her braking process. She can barely stop the car over the acceleration. It did it once today and has never done it before and didnt do it the next time she drove it. Any ideas
Here is what I am thinking
1 stuck throttle cable
2 torque converter
3 tranny issue

thanks for any input u may have\
nick
slowassgtx is offline   Reply With Quote
Old 03-30-2005, 09:36 PM   #2
atc3434
Grand Am Again
 
atc3434's Avatar
 
AKA: Andrew
Join Date: Apr 2003
Location: Auburn, NY
Age: 31
Posts: 1,999
Vehicle: 1999 Grand Am SE
atc3434 Gettin' there
Send a message via AIM to atc3434
TPS sensor... bet its bad, causing a high idle, hence the forward speed. Probably shifts like hell too...

Syracuse huh? Awesome, I'm from Weedsport. Whats your car look like, maybe I've seen it around? If your interested, I'm trying to get a bunch of people to meet up some time, the more the merrier.
__________________

1999 Grand Am SE2 - Blue, TOG Headers, SLP Exhaust, DHP - SOLD
1996 Vert' Z-28 - M6, magnaflow muffler-back, K&N FIPK, Hurst Short-throw - 13.6 @ 103mph.

2006 Dodge Charger R/T Daytona - Go Mango Orange #2832 of 4000. Tune/exhaust. 14.009@97mph.
2002 Saab 9 5 Aero Wagon - 3" turboback/tune. 17psi of sleeper fun just waiting to surprise you.
atc3434 is offline   Reply With Quote
Old 03-31-2005, 12:45 PM   #3
slowassgtx
GAGT - Newbie
 
Join Date: Mar 2004
Location: syracuse
Posts: 6
Vehicle: 98 grand prix GTX
slowassgtx Gettin' there
well its my gf's car. I have a 00 SS camaro, u might see me around its dark blue with chrome zr1 wheels. Thanks for the help on the GA though...
slowassgtx is offline   Reply With Quote
Old 03-31-2005, 01:05 PM   #4
2003SCT
GAGT - Senior Member
 
2003SCT's Avatar
 
Join Date: Feb 2004
Location: Las Vegas, NV
Age: 35
Posts: 1,709
Vehicle: 2003 Grand Am SC/T
2003SCT a trusted member
I've had that happen like twice too..coming out of work after work..

CHRIS
__________________
UNLV Alumni...Go Rebels!

2003 Grand Am SC/T Coupe in White. Borla Cat-Back, F/R Speedbuilt sway bars, H&R Sports/KYB, 18" Misano Lightweights wrapped in Falken FK-452 Euro-Sports and ZAINO!

2000 Chevrolet S10 Flareside: K&N Intake, Truxedo Tonneau and Gibson Cat Back
2003SCT is offline   Reply With Quote
Old 03-31-2005, 01:25 PM   #5
mr_eh
Hi.
 
mr_eh's Avatar
 
AKA: Pasquale
Join Date: Aug 2002
Location: Staten Island, NY
Age: 32
Posts: 4,405
Vehicle: 05 Srt-4 / 00GrandAmSE
mr_eh has disabled reputation
Send a message via AIM to mr_eh
mine does this but i can brake it easily, but after i start it it'll start rolling on its own then surge and take off ... its rather amusing...
__________________
4cyl ga se -> 431whp srt4 -> 600whp s14? wtf.
mr_eh is offline   Reply With Quote
Old 04-02-2005, 04:56 PM   #6
1hotgagt
GAGT - Member
 
Join Date: Mar 2005
Location: philly pa
Age: 27
Posts: 80
Vehicle: 2001 grand am GT sedan
1hotgagt Gettin' there
Send a message via AIM to 1hotgagt
mine does it too while im coasting in traffic it just takes off but it easily stops when i step on the brakes
1hotgagt is offline   Reply With Quote
Old 04-03-2005, 10:43 AM   #7
dcb2001gt
GAGT - Newbie
 
Join Date: Jan 2003
Location: Philadelphia
Age: 49
Posts: 29
Vehicle: 2001 GAGT
dcb2001gt Gettin' there
It is definitely the TPS sensor. Don't mess around change it. It only costs ~26 bucks and changes in about ten minutes.
dcb2001gt is offline   Reply With Quote
Old 04-03-2005, 11:01 AM   #8
Graxall
GAGT - Junkie
 
Graxall's Avatar
 
AKA: Rich
Join Date: Sep 2004
Location: Manahawkin, NJ
Age: 27
Posts: 3,312
Vehicle: 2008 BMW 528xi
Graxall Gettin' there
Send a message via AIM to Graxall
little off topic but do our cars have an idle control or is it just manual cars, i know my friends mitsu. 3000gt has a idle control that u can get to to adjust the idle. As the for the acceleration my car does the same thing but not barely noticable, also for fun with this go on a major highway and put it on cruise control at 80mph and put ur feet up, u slow down then the cruise kicks in and it feels like ur accelerating to 100 :-P
__________________
Cardomain|Gm Tuners|Oznium|PFYC|Grafx Werks|Custom Car Grills|MP Racing|Milzy Motor Sports|
Quote:
Originally Posted by 2002GT View Post
AJ - sometimes I think you talk out of your ass.
Quote:
Originally Posted by notsoaveragej0e View Post
AJ's stackin' teh gay, and Grax is stackin teh booze.
Graxall is offline   Reply With Quote
Old 04-03-2005, 11:53 PM   #9
2002AmSE
3.4L SE1 54.5k miles
 
Join Date: Jul 2003
Location: Minnesota, USA
Age: 28
Posts: 506
Vehicle: White 2002 GrandAm SE1
2002AmSE has disabled reputation
What rpm's is it running. When I start my car with a cold engine and put it in gear it and it will accelerate to about 25 mph without touching the gas. It's because my car idles at 1200rpm when the engine is cold for the first few minutes. It has done that since I got it.

If the rpm is higher than 1200rpm while in gear with no gas, theres a problem. If after 15 seconds after starting the car it hasn't dropped below about 1200rpm, there is a problem.

Some people will say my car has a problem, but I think that something changed in the years, my moms 99 will start in the dead of winter and immediadetly idle at 600rpm, but everyone I know with a newer grand am does the same as mine, but maybe someone is still wrong, if something is 'wrong' with mine I won't fix it because it isn't causing any harm.
__________________
White 2002 Grand Am SE1 3.4L 54,500 miles
2002AmSE is offline   Reply With Quote
Old 04-04-2005, 07:46 AM   #10
1hotgagt
GAGT - Member
 
Join Date: Mar 2005
Location: philly pa
Age: 27
Posts: 80
Vehicle: 2001 grand am GT sedan
1hotgagt Gettin' there
Send a message via AIM to 1hotgagt
how do you change the TPS sensor and were is it located?
1hotgagt is offline   Reply With Quote
Old 04-04-2005, 09:15 AM   #11
italo_grandam
GAGT - Newbie
 
Join Date: Jul 2004
Location: Toronto, Ont
Age: 29
Posts: 1
Vehicle: 1999 Grand Am Se 3400
italo_grandam Gettin' there
my 99 grand am se was doing the same but i unplugged my cruise control box under the hood and covered the electric outlets with plastic and so far so good it used to do it a lot but now its ok. i found that if you pull over turn the car off and re-start the car it sometimes stops the problem, it can be very dangerous to drive around with since it tends to accelerate when stoping

Last edited by italo_grandam; 04-04-2005 at 12:28 PM.
italo_grandam is offline   Reply With Quote
Old 09-19-2013, 01:25 PM   #12
ItsMeScottG
Tech Guy
 
ItsMeScottG's Avatar
 
AKA: Scott
Join Date: Jun 2012
Location: Houston, Texas
Age: 21
Posts: 671
Vehicle: 2005 BMW 330CI ZHP
ItsMeScottG Gettin' there
Quote:
Originally Posted by atc3434 View Post
TPS sensor... bet its bad, causing a high idle, hence the forward speed. Probably shifts like hell too...

Syracuse huh? Awesome, I'm from Weedsport. Whats your car look like, maybe I've seen it around? If your interested, I'm trying to get a bunch of people to meet up some time, the more the merrier.
I know this is a very old posting, however this is the only post that I can find that sounds similar to the issue that has been occurring with my GA. Sometimes when I start my GA and put it into drive, my car takes off by itself without me pressing the accelerator. My car did it again after work last night, without me pressing the accelerator my car was accelerating to like 25mph. I restarted my car twice and it was still having the same problem so I drove it a few miles down the road and then restarted my car again and the issue was resolved.

This issue has been happening for a few months off and on with my GA. The issue is so annoying, I can deal with it by using the brake petal but id really like to fix the issue. No dash lights are on at all what so ever, any ideas?
__________________
Previously a 2003 Pontiac Grand Am SE2 3.4L V6

SC/T Spoiler, PFYC Sway SpeedBuilt bars, PFYC SpeedBuilt strut braces, Rear disc brake setup, Stainless Steel Braided Brake Lines, red painted calipers, 20% Black Tint, Cat-Back Exhaust, Amber Grille Lighting, Pioneer AVIC-940BT with XM, Live Traffic, & Rear-view Camera, Front Bra, lower bumper grille, Stubby Antenna, Michelin Defender Tires...

My Current vehicle:
2005 BMW 330CI ZHP
ItsMeScottG is offline   Reply With Quote
Old 09-19-2013, 01:48 PM   #13
sleepyalero
▂ ▃ ▅ ▆ █ ▆ ▅ ▃ ▂
 
sleepyalero's Avatar
 
AKA: Nathan
Join Date: Jul 2011
Location: Unknown.
Posts: 5,313
Vehicle: 2001 olds alero GLS
sleepyalero a trusted member
That sounds like a problem i have every once in awhile as well. Car idles high i cant put it in first, give it no gas and it goes on its own and accelerates then hard to stop. So far i havent had a problem, but idk what it is.
__________________
2001 | Alero GLS | 3400 | 6MT

Mods:F40 6 speed swap. Pacesetter headers. Pacesetter 2.5" piping to Flowmaster muffler. CAI. MMS solid motor mount. MMS transmission mounts. MMS stainless allen bolts. MMS header gaskets. MMS custom no cat downpipe. MMS TB delete heater tube. Prosport Gauges. AEM A/F wideband. 65mm TCE TB. 8000K HID's. Sparco Racing Seats. MMS Port/polish UIM/LIM. BBS SR Wheels. Lowered. Baer brakes. A/C delete. SC/T spoiler.
sleepyalero is offline   Reply With Quote
Old 09-19-2013, 03:11 PM   #14
ItsMeScottG
Tech Guy
 
ItsMeScottG's Avatar
 
AKA: Scott
Join Date: Jun 2012
Location: Houston, Texas
Age: 21
Posts: 671
Vehicle: 2005 BMW 330CI ZHP
ItsMeScottG Gettin' there
Quote:
Originally Posted by sleepyalero View Post
That sounds like a problem i have every once in awhile as well. Car idles high i cant put it in first, give it no gas and it goes on its own and accelerates then hard to stop. So far i havent had a problem, but idk what it is.
Same issue here! anyone have any ideas as far as a fix for the issue?
__________________
Previously a 2003 Pontiac Grand Am SE2 3.4L V6

SC/T Spoiler, PFYC Sway SpeedBuilt bars, PFYC SpeedBuilt strut braces, Rear disc brake setup, Stainless Steel Braided Brake Lines, red painted calipers, 20% Black Tint, Cat-Back Exhaust, Amber Grille Lighting, Pioneer AVIC-940BT with XM, Live Traffic, & Rear-view Camera, Front Bra, lower bumper grille, Stubby Antenna, Michelin Defender Tires...

My Current vehicle:
2005 BMW 330CI ZHP
ItsMeScottG is offline   Reply With Quote
Old 09-19-2013, 03:32 PM   #15
sleepyalero
▂ ▃ ▅ ▆ █ ▆ ▅ ▃ ▂
 
sleepyalero's Avatar
 
AKA: Nathan
Join Date: Jul 2011
Location: Unknown.
Posts: 5,313
Vehicle: 2001 olds alero GLS
sleepyalero a trusted member
Well since i have a 6 speed im not sure. I can let the clutch out without gas and it pulls like im giving it gas. Hasnt done it for a couple weeks now.
__________________
2001 | Alero GLS | 3400 | 6MT

Mods:F40 6 speed swap. Pacesetter headers. Pacesetter 2.5" piping to Flowmaster muffler. CAI. MMS solid motor mount. MMS transmission mounts. MMS stainless allen bolts. MMS header gaskets. MMS custom no cat downpipe. MMS TB delete heater tube. Prosport Gauges. AEM A/F wideband. 65mm TCE TB. 8000K HID's. Sparco Racing Seats. MMS Port/polish UIM/LIM. BBS SR Wheels. Lowered. Baer brakes. A/C delete. SC/T spoiler.
sleepyalero is offline   Reply With Quote
Old 09-19-2013, 06:43 PM   #16
rjs_boy
GAGT - Member
 
Join Date: Oct 2002
Location: Orlando, FL
Posts: 128
Vehicle: 1999 Grand Am GT Sedan
rjs_boy Gettin' there
Only time I've had that happen was when the PCV tube stopped sealing into the UIM, behind the Throttle body. The car idled horribly and the vac leak was significant enough that once I got it moving, I didn't need to press the accelerator at all. Going to the parts store was kinda fun, having to run it in 2nd gear to keep within the speed limit without having to ride the brakes. But fixing it in the parking lot and having it run perfect on the way home was also nice.


You don't mention rough idling or anything which sounds like a vacuum leak...have you tried disconnecting the cruise control cable from the throttle body?

How is the car idling when it acts up? Does the idle stay high, or bounce around?

I would suspect something either vac leak or throttle related is causing this...sticky accelerator cable, malfunctioning cruise control, buildup in/around the throttle plate, IAC valve.
rjs_boy is offline   Reply With Quote
Old 09-19-2013, 07:01 PM   #17
sleepyalero
▂ ▃ ▅ ▆ █ ▆ ▅ ▃ ▂
 
sleepyalero's Avatar
 
AKA: Nathan
Join Date: Jul 2011
Location: Unknown.
Posts: 5,313
Vehicle: 2001 olds alero GLS
sleepyalero a trusted member
Ive cleaned/replaced all sensors coming out of the TB. I could try to see if its my cruise cable sticking but i doubt it.
__________________
2001 | Alero GLS | 3400 | 6MT

Mods:F40 6 speed swap. Pacesetter headers. Pacesetter 2.5" piping to Flowmaster muffler. CAI. MMS solid motor mount. MMS transmission mounts. MMS stainless allen bolts. MMS header gaskets. MMS custom no cat downpipe. MMS TB delete heater tube. Prosport Gauges. AEM A/F wideband. 65mm TCE TB. 8000K HID's. Sparco Racing Seats. MMS Port/polish UIM/LIM. BBS SR Wheels. Lowered. Baer brakes. A/C delete. SC/T spoiler.
sleepyalero is offline   Reply With Quote
Old 09-19-2013, 08:35 PM   #18
plastic_indian
GAGT - Member
 
plastic_indian's Avatar
 
AKA: Mark
Join Date: Apr 2008
Location: Naptown, IN
Posts: 316
Vehicle: 04 2DS
plastic_indian Gettin' there
TPS or IAC problems are probably the most common causes of this on the LA1.

If available, use a scan tool to check for pending or history codes. (Or current MIL codes if the engine light bulb is burned out!)

Check the TPS for a smooth transition from near 0 volts closed to near 5 volts WOT. In the absence of a scan tool an analog multimeter can show this more clearly than a digital. TPS problems usually set trouble codes, however. The pigtail to the sensor can also become damaged, resulting in a quirky signal.

IAC problems are harder to look at without a scan tool. Ideally, you want to monitor desired idle RPM, actual RPM and IAC counts for disparity. A sticking IAC will, in many instances, not set a trouble code. A stuck IAC can sometimes be cleaned, but many times this is fruitless. If you do not have a scan tool, rapping on a suspect IAC with a screwdriver handle while the problem is presenting will often allow the idle speed to normalize or at least fluctuate.

ECT or IAT anomalies (particularly an open circuit, which causes a -40 F reading) can cause elevated idle problems, but this again usually sets a DTC.

I know of one particular '04 that has been plagued by this intermittent problem. While it is exceptionally well maintained, it is quite high mileage. We have not been able to resolve the issue to date. If time/money/epiphany all come together at some point and we find the cause, I will try and remember to post.
__________________
Where was Bunkie when we needed him?

Quote:
Originally Posted by cardude007617 View Post
I'm pretty sure you don't need 600HP to merge safely onto a freeway. and if you do, you're doing it wrong.
plastic_indian is offline   Reply With Quote
Old 09-19-2013, 11:58 PM   #19
sleepyalero
▂ ▃ ▅ ▆ █ ▆ ▅ ▃ ▂
 
sleepyalero's Avatar
 
AKA: Nathan
Join Date: Jul 2011
Location: Unknown.
Posts: 5,313
Vehicle: 2001 olds alero GLS
sleepyalero a trusted member
Ive changed all those sensors with so far little luck atm . I am getting hpt soon and will do some data logging to see if i can get the rpms to idle high, if it does i can see whats opening up and can hopefully rule out, why.
__________________
2001 | Alero GLS | 3400 | 6MT

Mods:F40 6 speed swap. Pacesetter headers. Pacesetter 2.5" piping to Flowmaster muffler. CAI. MMS solid motor mount. MMS transmission mounts. MMS stainless allen bolts. MMS header gaskets. MMS custom no cat downpipe. MMS TB delete heater tube. Prosport Gauges. AEM A/F wideband. 65mm TCE TB. 8000K HID's. Sparco Racing Seats. MMS Port/polish UIM/LIM. BBS SR Wheels. Lowered. Baer brakes. A/C delete. SC/T spoiler.
sleepyalero is offline   Reply With Quote
Old 09-24-2013, 12:06 PM   #20
ItsMeScottG
Tech Guy
 
ItsMeScottG's Avatar
 
AKA: Scott
Join Date: Jun 2012
Location: Houston, Texas
Age: 21
Posts: 671
Vehicle: 2005 BMW 330CI ZHP
ItsMeScottG Gettin' there
Would changing the TPS sensor help resolve the issue? Anyone other than me and sleepy experienced this? My car hasn't done it for a few days now but I'd still like to fix the issue so it doesn't happen again.
__________________
Previously a 2003 Pontiac Grand Am SE2 3.4L V6

SC/T Spoiler, PFYC Sway SpeedBuilt bars, PFYC SpeedBuilt strut braces, Rear disc brake setup, Stainless Steel Braided Brake Lines, red painted calipers, 20% Black Tint, Cat-Back Exhaust, Amber Grille Lighting, Pioneer AVIC-940BT with XM, Live Traffic, & Rear-view Camera, Front Bra, lower bumper grille, Stubby Antenna, Michelin Defender Tires...

My Current vehicle:
2005 BMW 330CI ZHP
ItsMeScottG is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 02:29 AM.


Powered by vBulletin® Version 3.7.2
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright 2011 GrandAmGT.com
MilzyMotorsports.com