Beat the "sticky throttle pedal" topic again

dawgfan · April 18, 2006

Did anyone ever write out or illustrate the instuctions for complete novices? Can this cleaning be performed by someone without a lot of experience? I've got a 99 Sierra that's started doing it and I don't want to take it to the shop.

ChevyTech007 · April 18, 2006

No big deal. Take the air duct off the throttle body and use carb cleaner or throttle plate cleaner. Open the throttle blade and use a toothbrush to clean it out good. It will run very rough for a minute so don't let that scare you when your done.

ps. you might want to use a toothbrush that you don't intend to use on your teeth again.

Wingnut · April 18, 2006

ps. you might want to use a toothbrush that you don't intend to use on your teeth again.

<{POST_SNAPBACK}>

Balderdash. It adds a nutty aftertaste to the refreshment of arm and hammer baking soda toothpaste.

chuck16 · April 21, 2006

Is this to resolve the sticky gas pedal problem that I've just recently been experiencing????

Cheers

Evan

Wonder if my CAI has anything to do with it...

MS3DALE · April 21, 2006

Heres the correct fix:

Document ID# 1269746

2000 Chevrolet Chevy K Silverado - 4WD

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Subject: Increased Accelerator Pedal Effort, Idle Instability (Clean Throttle Body and Adjust Blade) #02-06-04-054B - (03/17/2003)

Models: 1999-2002 Chevrolet Silverado

2000-2002 Chevrolet Suburban, Tahoe

2002 Chevrolet Avalanche

1999-2002 GMC Sierra

2000-2002 GMC Yukon, Yukon XL

with 4.8L or 5.3L V8 Engine (VINs V, T, Z -- RPOs LR4, LM7, L59)

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This bulletin is being revised to add condition information. Please discard Corporate Bulletin Number 02-06-04-054A (Section 06-Engine).

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Condition

Some customers may comment on an idle instability and/or a higher than expected accelerator pedal effort from the idle position.

Cause

Condition may be caused by deposits in the throttle body bore and on the throttle plate.

Correction

Important: This procedure only applies to cable actuated throttle bodies on the models listed above. This procedure should not be performed on electronically controlled throttle bodies or on any vehicle or engine that is not listed above in the Models section.

Verify that the cause for this condition is not a damaged or binding throttle cable.

Remove the air intake duct. Refer to Air Cleaner Duct Replacement.

Inspect the vehicle for installation of a fixed orifice PCV valve, refer to Corporate Bulletin Number 01-06-01-029B for PCV valve identification. Vehicles undergoing this throttle body procedure MUST use a Fixed Orifice PCV Valve, P/N 12572717.

Clean throttle body bore and throttle valve plate of carbon using a shop rag and an appropriate cleaner. Refer to Engine Controls Repair Procedures - Throttle Body Cleaning Procedure.

Select the correct plug for the size of the air bypass hole in the throttle body being serviced. Use a 1/8-inch (.125") drill bit to determine which plug to use.

• Vehicles built before introduction of the Fixed Orifice PCV Valve will have a 3.75 mm (.150") air bypass hole in the throttle plate. The 1/8-inch drill bit is smaller than the air bypass hole in these throttle bodies and can be inserted into the bypass hole. To plug the air bypass hole in these vehicles requires the yellow plug, P/N 12580749.

• Vehicles built after introduction of the Fixed Orifice PCV Valve will have a 2.6 mm (.104") air bypass hole in the throttle plate. The 1/8-inch drill bit is larger than the air bypass hole in these throttle bodies and cannot be inserted into the bypass hole. To plug the air bypass hole in these vehicles requires the red plug, P/N 12581011.

Insert the appropriate plug (1) into the air bypass hole in the throttle plate. Insert the "tail" end of the plug through the throttle plate air bypass hole.

Open the throttle plate to allow access to the tail end of the plug. Pull the tail section to securely position the plug into the air bypass hole and trim excess material (1) from plug.

Turn ignition key to the on position, with engine off.

Use the Tech 2 Scan tool to read initial TPS voltage.

Important: TPS voltage cannot exceed .69 V. If the vehicle has an initial TPS voltage greater than .61 V, replace the Throttle Body Assembly. This part is currently on parts restriction. Contact the General Motors Powertrain Quality Center for assistance.

Using the Tech 2 Scan tool and a T15 driver to rotate the Minimum Air Rate screw, increase TPS voltage by .08 Volts (Refer to TPS Voltage Chart below).

Turn ignition key to the off position. Verify that the accelerator pedal moves freely - Depress the accelerator pedal to the floor and release.

Install the air intake duct. Refer to Air Cleaner Duct Replacement.

Start engine.

Using the Tech 2 scan tool, monitor TPS voltage and verify the TPS voltage is no greater than 0.69V.

Road Test Vehicle.

Important: If an increased accelerator pedal effort condition still exists after performing this bulletin, throttle body replacement may be required. Please contact the General Motors Powertrain Quality Center for assistance, as the throttle body is currently on a parts restriction program.

TPS Voltage Chart Initial TPS Voltage

TPS Voltage After .08 Volt Increase

0.45 V

0.53 V

0.47 V

0.55 V

0.49 V

0.57 V

0.51V

0.59 V

0.53 V

0.61 V

0.55 V

0.63 V

0.57 V

0.65 V

0.59 V

0.67 V

0.61 V

0.69 V

If initial TPS voltage is greater than .61 V Replace Throttle Body Assembly

Parts Information

Part Number

Description

Qty

12580749

Plug, Throttle Plate - Yellow

1

12581011

Plug, Throttle Plate - Red

1

Parts are currently available from GMSPO.

Warranty Information

For vehicles repaired under warranty, use:

Labor Operation

Description

Labor Time

J5984

Throttle Body - Clean and Adjust

0.6 hr

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

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Document ID# 1269746

2000 Chevrolet Chevy K Silverado - 4WD

It worked on my '99. I was getting tired of cleaning it every 8-10,000 miles,When GM came out with this bulletin I performed it and never had any issues after that!

hoorders · April 21, 2006

Heres the correct fix:

Document ID# 1269746

2000 Chevrolet Chevy K Silverado - 4WD

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Subject: Increased Accelerator Pedal Effort, Idle Instability (Clean Throttle Body and Adjust Blade) #02-06-04-054B - (03/17/2003)

So I get the cleaning proceedures............pretty straight forward......but I am a little confused about the plugs for the air by pass hole........in the cleaning instructions it sounds like we need to plug this hole and leave it plugged???? why???.........or am I miss reading it?.....

tim d · April 21, 2006

hmmm? i recently cleaned my throttle bottle and valve with throttle body cleaner and toothbrush... because the peddle was sticking.

now my truck runs like crap. have to gas the hell out of it to get it to move, stalls, runs like crap... sounds and feels like it's missing real bad.

smells of gas real bad...seems like it's starving of air...cats aren't glowing...new cat of last year.

it's gotta be sensor related.

i chnaged the plugs, wires etc (they all fire). new air filter. (new fuel pump last year). i put a new coil, MAP sensor, new TPS (throtttle position sensor).

when i did those last 3 items, i guess it went in LIMP mode...would run great for a day...then turned to crap again!!!! truck runs better in LIMP mode for soemreason..then when system kicks back in...back to terrible...lights blinking ll the time after steady lights.

uggh. baffled.

96 4.3 2 wheeldrive c1500 auto

MS3DALE · April 21, 2006

OK,Let me try to clearify it a little.......

After the cleaning you have to plug the hole in the throttle blade,But first you have to determine which plug you need,Thats where an 1/8" drill bit comes into play,If you can insert the 1/8" drill bit into the hole you need the yellow plug part #12580749,If you cannot insert into the hole you need the red plug part #12581011.

Now this is where its gets a little tricky,If you have the larger hole that requires the yellow plug you need to change the PVC valve to a "Fixed-Orifice-PCV-Valve" which is part number 12572717.

I would double check to make sure you the "Fixed-Orifice PCV Valve" no matter what size hole you have in the throttle blade,The "Fixed-Orifice PCV Valve" WILL NOT rattle when you shake it (I.E. It has no moving parts inside of it)

Then you need a scan tool to read the TPS voltage because you have to adjust the throttle blade using a T15 driver to rotate the Minimum Air Rate Screw,You have to increase the voltage .08 volts,This "opens up" the throttle blade slightly to make up for plugging the hole in the throttle blade itself.

Thats it,Your done!!!! No more sticking throttle,Believe me its sooo nice!!!

Let me know if you have any other questions.

Rich

tim d · April 21, 2006

i chnaged my TPS also.... just unbolted the 2 screws and unplugged, droppped in another. is there anything else i should have done to set it or something?? truck ran great for a few hours...then went to crap again.

thanx!

ps..i also have digimoto scan tool/software....my abosulte throttle position was readin 0 before i replaced it when using the accelerateor...so changed TPS....didn't check agian since it seemed to run good..but not anymore...i have to check reading again.

MS3DALE · April 21, 2006

Tim,Keep in mind that the procedure I listed is for the "New-Body-Style" trucks from '99 to '02 with the 4.8 or 5.3-V8's.

Its not for the "Old-Body-Style" trucks such as yours.

chuck16 · April 22, 2006

Not to beat a dead horse but, I want to be clear.

You take your intake pipe off.

Push the intake blade and clean all around it and the throttle body with Carb Cleaner.

Then you have to plug the PCV Valve, permanently? Why can't you just put it all back together after you clean the Throttle body and Intake blade?

I just want to have all my ducks in a row before I attempt this cleaning. The sticky pedal thing is really starting to bug me. Only does it when she's really hot.

FYI -- 99' Silverado 1500 5.3 L listed below.

MS3DALE · April 22, 2006

Then you have to plug the PCV Valve, permanently? Why can't you just put it all back together after you clean the Throttle body and Intake blade?

NO,You DO NOT plug the PCV Valve,But you must make sure that you have the "Fixed-Orifice-PCV-Valve" This is a PCV Valve that has no moving parts inside of it so it WILL NOT rattle when you shake it.

If you do not have the "Fixed-Orifice-PCV-Valve" you must install one for this procedure to work,Ask for part number 12572717 at your GM dealer.

What you must plug is the hole in the throttle body blade,There are two different size holes,Refer to my earlier post on determining what size and part number plug to use.

Then you must increase the voltage of the Thottle Position Sensor by .08 volts by turning up the Minimum Air Rate Screw using a scan tool,This opens up the throttle blade slightly.

You can just keep cleaning the throttle body if you want,But if its anything like my '99 I had it will require cleaning frequently.

Believe me having this bulletin performed is the correct and only way to properly solve the sticky throttle pedal problem.

svensk · September 16, 2006

I have a question about the intake. Can I just install the new "fixed oriface" pcv valve and just not worry about plugging the throttle blade hole and mess with that crap? Will just installing the new style valve alone fix the amount of crud building up in my intake?

MS3DALE · September 16, 2006

I have a question about the intake. Can I just install the new "fixed oriface" pcv valve and just not worry about plugging the throttle blade hole and mess with that crap? Will just installing the new style valve alone fix the amount of crud building up in my intake?

Yes,You can just install the "fixed-orifice" PCV valve, and not plug the hole in the throttle blade and adjust the TPS voltage,But... It will not fix the sticking throttle pedal.

The fixed orifice PCV valve was designed to prevent oil-consumption,See bulletin below on that subject.........

Subject: Higher Than Expected Engine Oil Consumption (Replace PCV Valve) #01-06-01-029B - (07/19/2002)

Models: 2002 Chevrolet Avalanche

1999-2002 Chevrolet Silverado, Suburban, Tahoe Models

2002 Cadillac Escalade, Escalade EXT

1999-2002 GMC Denali, Sierra, Suburban, Yukon Models

with 4.8L, 5.3L or 6.0L Engine (VINs V, T, N, U -- RPOs LR4, LM7, LQ9, LQ4)

Condition

Some customers may comment on higher than expected engine oil consumption. They may further comment on consumption in the range of 3,200 km (2,000 mi) or less per quart (0.946 liter) of oil under normal driving conditions.

Cause

The condition may be due to the positive crankcase ventilation (PCV) valve flow rate under certain engine operating conditions.

Correction

Verify that the oil consumption is not the result of an oil leak or other engine concern.

The dealer should perform an oil consumption test. The vehicle should have accumulated over 6,450 km (4,000 mi) before establishing the oil consumption rate. Reference Corporate Bulletin Number 01-06-01-011, Information on Engine Oil Consumption Guideline, for details.

Remove the PCV valve and inspect the hose going to the intake manifold for signs of excessive oil being present.

If excessive oil is present in the PCV hose, replace the PCV valve (Type 948C) (2) with a new-style fixed orifice PCV valve, GM P/N 12572717(1).

Important: The new style fixed orifice PCV valve contains no moving parts, and does not rattle when shaken.

If the vehicle has an orifice style PCV valve, investigate other causes for high oil consumption.

Parts Information

Part Number

Description

Qty

12572717

Valve, PCV

1

Parts are currently available from GMSPO.

Warranty Information

For vehicles repaired under warranty, use:

Labor Operation

Description

Labor Time

J6000

Valve, PCV - Replace

Use published labor operation time

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

Document ID# 901494

z85violator · September 19, 2006

wait wait wait

let me see if i can understand this

i plug my exhust with my throttle body blade and use the red plug on my fixed orfice?, or do i put the 1/8 drill bit in my fixed orfice and throw the yellow plug into the intake?

hehehehehehe