Gas Pedal Doest Not Work

[Mr. Roo]

I have a 2003 Bounder model W32 with the Chevy 8.1 Vortec engine. The other day we pulled into a campground shut the motor off and went in to register. Came back and started the rig and the "check engine" light came on and the engine would only idle. Pressing the gas pedal would not increase engine RPM. After shutting of and trying 3 or 4 times the gas pedal worked as normal but the "check engine" light stayed on. The following morning I started the rig and the "check engine" light was out and the gas pedal worked normal.

Has anybody else had the same problem. If so what was the cause? Otherwise anybody have any ideas?

Al

[scotts_rv]

I haven't had this problem but it sounds like a failing throttle position sensor. With the check engine light on you may be able to pull a code off using an OBD II reader to narrow it down.

[LETMGROW]

Originally Posted by Mr. Roo

I have a 2003 Bounder model W32 with the Chevy 8.1 Vortec engine. The other day we pulled into a campground shut the motor off and went in to register. Came back and started the rig and the "check engine" light came on and the engine would only idle. Pressing the gas pedal would not increase engine RPM. After shutting of and trying 3 or 4 times the gas pedal worked as normal but the "check engine" light stayed on. The following morning I started the rig and the "check engine" light was out and the gas pedal worked normal.

Has anybody else had the same problem. If so what was the cause? Otherwise anybody have any ideas?

Al

I believe your 2003 8.1 has a drive by wire throttle system. No mechanical connection between the gas pedal and the throttle valve. There is a potentiometer mounted to the gas pedal bracket which sends a message to the engine control module and the module commands the throttle valve opening.
I would have the engine control system scanned for a code. Even though the check engine light is off now there should be a code stored in the history bank of the computer. After a designated number of starts if the problem doesn't return the computer will clear itself of codes. Having the code recorded now could greatly aid someone in the future if the problem occurs again and has to be diagnosed.
Lynn

[TeJay]

I have to agree with #2 poster scotts rv. Unless things have changed (and maybe they have) the TPS is nothing more than a variable resistor and it is a reflection of the throttle plate opening angle. That is very similar to a volume control on the old car radios.

A 5 -V reference voltage is used. The idle voltage to the CPU might be .6 volts. As the pedal is pushed down that voltage will rise until WOT (Wide Open Throttle) is reached which might be about 4.8 V's. That is the only input from the operator as far as engine speed.

I'm thinking when you had no throttle response there was a bad spot on the variable resistor in the TPS. You can actually monitor the TPS output voltage with a Digital Volt meter or a scanner.

Any decent technician can do that and byu working the throttle (key on and engine off) and watch the voltage output until it malfunctions again. Or just change the TPS switch. It's a simple fix.

Those TPS switches seldom fail. I don't believe I ever saw one go bad but there's always a first time for anything.

TeJay

[twinboat]

I tend to agree with LETMGROW who was refering to the throttle pedal sender, on the gas pedal.

With no throttle cable, it sends an electric signal to a small electric, throttle motor, on the engines throttle body to open and close it.

Some reading suggests you pump the gas pedal a few times, engine off, to clean the "volume control like" reostat.

You may also want to check the connector on the wire leading from the pedal control.