STUCK gas pedal

[GMCTyphoon]

I've been reading about the sticky gas pedal and cleaning out the throttle body to take care of it, but now and again, my throttle pedal just plain old STICKS. I press so hard on the gas that I think I'm going to break the cable and it still does nothing. I shut the truck off for a few mins, get in and it works like it should.

 

I have cleaned the throttle body with carb cleaner (while on the truck) as best I can, I've removed the cable and looked for burrs or anywhere it could hang up, and the cable is perfect. The pedal itself moves freely and there is no issue there.

 

I have to assume the throttle body is the culprit, but has anyone had this same symptom where it just locks up?? If so, whats the proper fix? Take the TB off the truck, really clean the heck out of it, look for where it might be hanging up and reinstall?

 

Thanks for your help; really stinks when it acts up waiting at a stop light or something!!!

 

-adam

[Rolandd]

You may want to look and see if any of the mechanical item connected to the throttle linkage are binding (e.g.: throttle position sensor, off idle switch, kickdown cable, WOT sensor). I would also check for burrs on the butterfly plates at the bottom of the TBI unit and bent parts. However, usually bent parts create a constant issue and you are describing an intermittant issue. Can you at all isolate the behavior, such as when the A/C is running, when the truck is warm or cold, etc. The idle motor on the TBI could be extending itself in a way that is binding the throttle linkage.

[GMCTyphoon]

You may want to look and see if any of the mechanical item connected to the throttle linkage are binding (e.g.: throttle position sensor, off idle switch, kickdown cable, WOT sensor).  I would also check for burrs on the butterfly plates at the bottom of the TBI unit and bent parts.  However, usually bent parts create a constant issue and you are describing an intermittant issue.  Can you at all isolate the behavior, such as when the A/C is running, when the truck is warm or cold, etc.  The idle motor on the TBI could be extending itself in a way that is binding the throttle linkage.

 

<{POST_SNAPBACK}>

 

 

Thanks Roland. The problem shows up only when the truck is cold. Not necessarily on the first time you step on the gas, but say you start the truck after work, drive to the first stop sign at the end of the parking lot, then there it sits. The truck is a bare bones '01 without A/C, cruise etc. The only thing connected to the throttle body is the throttle cable; no kickdown cable. I only did a brief cleaning with carb cleaner, and it seemed to help for a day or so. I need to peel the TB off and really clean it and inspect for interference. I would have, but didn't have a replacement gasket (is it a paper gasket or an o-ring?). Thanks again.....

 

-adam

[ChevyTech007]

Subject: Increased Accelerator Pedal Effort from Idle Position (Clean Throttle Body and Adjust Blade) #04-06-04-079 - (10/25/2004)

 

 

 

Models: 1999-2002 Chevrolet Silverado

 

2000-2002 Chevrolet Suburban, Tahoe

 

2003-2004 Chevrolet Express

 

1999-2002 GMC Sierra

 

2000-2002 GMC Yukon, Yukon XL

 

2003-2004 GMC Savana

 

with 6.0L Engine (VIN U - RPO LQ4)

 

 

 

 

--------------------------------------------------------------------------------

 

Condition

Some customers may comment on 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 Service Bulletin 01-06-01-029B for PCV valve identification. Vehicles completing 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 5/32-inch drill bit to determine which plug to use.

• Vehicles built before introduction of the Fixed Orifice PCV Valve will have a 4.0 mm (.157") air bypass hole in the throttle plate. The 5/32-inch drill bit is smaller than the air bypass hole in these throttle bodies and can be inserted into the bypass hole. To reduce the air bypass hole in these vehicles requires the gray plug, P/N 12583703.

 

• Vehicles built after introduction of the Fixed Orifice PCV Valve will have a 3.65 mm (.144") air bypass hole in the throttle plate. The 5/32-inch drill bit is larger than the air bypass hole in these throttle bodies and cannot be inserted into the bypass hole. To reduce the air bypass hole in these vehicles requires the blue plug, P/N 12583704.

 

 

 

 

 

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. (Refer to Figure 1)

 

 

 

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. (Refer to Figure 2)

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.

 

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 .69V.

Road Test Vehicle.

 

 

TPS Voltage Chart Initial TPS Voltage

TPS Voltage After .08 Volt Increase

 

.45 V

.53 V

 

.47 V

.55 V

 

.49 V

.57 V

 

.51 V

.59 V

 

.53 V

.61 V

 

.55 V

.63 V

 

.57 V

.65 V

 

.59 V

.67 V

 

.61 V

.69 V

 

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

 

 

Parts Information

Part Number

Description

Qty

 

12583703

Plug, Throttle Plate - Gray

1 as req'd

 

12583704

Plug, Throttle Plate - Blue

1 as req'd

 

 

Parts are currently available from GMSPO.

[GMCTyphoon]

Thanks for the help Chevytech...next step is obviously to remove the TB and clean the whiz out of it; I did it as well as I could with it on the vehicle. It just worried me because it seemed like more of a problem than just a nuisance; sitting stranded at a green light with traffic backing up behind me stinks. I'll clean as best I can and see what happens.

 

[gmcman2]

i had the same problem with my gas pedal sticking. gm told me this and that and what i found was a ground problem. when the ground problem was corrected the pedal has not stuck since. this has been about three months ago and all is still well. just my two cents worth.

[MS3DALE]

i had the same problem with my gas pedal sticking. gm told me this and that and what i found was a ground problem. when the ground problem was corrected the pedal has not stuck since. this has been about three months ago and all is still well. just my two cents worth.

 

 

 

 

 

What does a bad ground have to do with a sticking throttle pedal?

[asilverblazer]

Maybe its a drive by wire. Open circuit means no gas pedal? I guess that would result in a non functioning pedal rather than a non moving pedal. If the circuit continuity was loss I would think you could play with the pedal all day long and it not do anything. Don't know why it would affect the pedal. Throttle body but not pedal...