99 Silverado Won't Idle

[Don99]

I've got a 99 Silverado 5.3 2wd with 104,000 miles. I was going out to lunch and when I started it up it immediately went dead. I tried starting it a couple more times and each time I could keep it running by keeping my foot on the accelerator but as soon as I let it idle it would go dead. We decided to go to lunch in my coworkers car. When we got back I was going to try to take it to the shop but when I cranked it (approx 2 hours later) it ran fine. I drove it around for a while and it is running fine now. Anybody got any idea why this might have happened? Or had a similar problem? I figure I'd be wasting my time taking in to the dealer when it's running fine because they wouldn't be able to diagnose the problem. BTW, it did not set a code, no service lights on. Any help or ideas would be appreciated.

 

Don

[Shaners]

Maybe there was a little moisture in the fuel or something.  Are the plugs original?  How about the fuel filter?

[Don99]

I replaced the plugs at 95,000 with regular Bosch Platinums (not the +4 deal).  I do need to replace the fuel filter.  I bought one but haven't had time to put it on yet.  Could the fuel filter cause the idling problem when the motor rev's fine?  It seems similar to a throttle position sensor problem I saw once before on a different car but when I called my dealer the service manager said those rarely give any trouble.  I'm gonna change out the fuel filter this evening.

[Don99]

I changed the fuel filter and added some fuel system cleaner this evening.  The truck ran fine on the way home from work.  Hopefully it won't give anymore trouble.  We'll see what happens.

 

Don

[Guest Friz]

I'm not too sure about the OBDII computers, but on the OBDI, you could disconnect the battery for 30 seconds and it would reset the computer.

Maybe the computer just had a momentary glitch.

I'm sure some of the OBDII owners could confirm this.