1999 Silverado Stumbles

I have a 1999 Chevy Silverado 4x4 with 64k miles, 5.3 L engine and
automatic tranny. The truck "stumbles" at different times. The
problem generally occurs when I first start the engine and put in gear.
Once I begin to give it more throttle, the problem starts to
dissipate. During acceleration at low rpm and slight throttle it also
stumbles/bucks. The truck seems low on power in overdrive but when it
kicks down, it seems to be ok. I have changes plugs and fuel filter.
No trouble codes or check engine light. The dealer was unable to find
anything wrong...it was working well when I took it in. Any Ideas? I
can recreate the problem by holding the brake and throttle, loading the
engine. Mostly this is noticed under 1500 rpm.

"

> wrote in message
oups.com...
>I have a 1999 Chevy Silverado 4x4 with 64k miles, 5.3 L engine and
> automatic tranny. The truck "stumbles" at different times. The
> problem generally occurs when I first start the engine and put in gear.
> Once I begin to give it more throttle, the problem starts to
> dissipate. During acceleration at low rpm and slight throttle it also
> stumbles/bucks. The truck seems low on power in overdrive but when it
> kicks down, it seems to be ok. I have changes plugs and fuel filter.
> No trouble codes or check engine light. The dealer was unable to find
> anything wrong...it was working well when I took it in. Any Ideas? I
> can recreate the problem by holding the brake and throttle, loading the
> engine. Mostly this is noticed under 1500 rpm.

This recreation surely sounds like bad plugs(worn cam symptoms too, but
with just 68K??). But originals should last 100K w/no problem. And why
could dealership not find a diagnostic trouble pattern when the problem was
being recreated? You DID install a proper set of AC's didn't you? s

I installed Bosch plugs. The auto parts guy said some folks had
trouble with the other than AC plugs.

sdlomi2 wrote:
> "
>
> > wrote in message
> oups.com...
> >I have a 1999 Chevy Silverado 4x4 with 64k miles, 5.3 L engine and
> > automatic tranny. The truck "stumbles" at different times. The
> > problem generally occurs when I first start the engine and put in gear.
> > Once I begin to give it more throttle, the problem starts to
> > dissipate. During acceleration at low rpm and slight throttle it also
> > stumbles/bucks. The truck seems low on power in overdrive but when it
> > kicks down, it seems to be ok. I have changes plugs and fuel filter.
> > No trouble codes or check engine light. The dealer was unable to find
> > anything wrong...it was working well when I took it in. Any Ideas? I
> > can recreate the problem by holding the brake and throttle, loading the
> > engine. Mostly this is noticed under 1500 rpm.
>
> This recreation surely sounds like bad plugs(worn cam symptoms too, but
> with just 68K??). But originals should last 100K w/no problem. And why
> could dealership not find a diagnostic trouble pattern when the problem was
> being recreated? You DID install a proper set of AC's didn't you? s

"Scooter" > wrote in message
ups.com...
>I installed Bosch plugs. The auto parts guy said some folks had
> trouble with the other than AC plugs.
>
> sdlomi2 wrote:
>> "
>>
>> > wrote in message
>> oups.com...
>> >I have a 1999 Chevy Silverado 4x4 with 64k miles, 5.3 L engine and
>> > automatic tranny. The truck "stumbles" at different times. The
>> > problem generally occurs when I first start the engine and put in gear.
>> > Once I begin to give it more throttle, the problem starts to
>> > dissipate. During acceleration at low rpm and slight throttle it also
>> > stumbles/bucks. The truck seems low on power in overdrive but when it
>> > kicks down, it seems to be ok. I have changes plugs and fuel filter.
>> > No trouble codes or check engine light. The dealer was unable to find
>> > anything wrong...it was working well when I took it in. Any Ideas? I
>> > can recreate the problem by holding the brake and throttle, loading the
>> > engine. Mostly this is noticed under 1500 rpm.
>>
>> This recreation surely sounds like bad plugs(worn cam symptoms too,
>> but
>> with just 68K??). But originals should last 100K w/no problem. And why
>> could dealership not find a diagnostic trouble pattern when the problem
>> was
>> being recreated? You DID install a proper set of AC's didn't you? s
>
Hey Scooter, I know the AC's are quite expensive (the platinum tip is
called for, isn't it?), but often perform significantly better than
non-AC's. HTH, s

sdlomi2 wrote:
> "Scooter" > wrote in message
> ups.com...
>
>>I installed Bosch plugs. The auto parts guy said some folks had
>>trouble with the other than AC plugs.
>>
>>sdlomi2 wrote:
>>
>>>"
>>>
> wrote in message
egroups.com...
>>>
>>>>I have a 1999 Chevy Silverado 4x4 with 64k miles, 5.3 L engine and
>>>>automatic tranny. The truck "stumbles" at different times. The
>>>>problem generally occurs when I first start the engine and put in gear.
>>>> Once I begin to give it more throttle, the problem starts to
>>>>dissipate. During acceleration at low rpm and slight throttle it also
>>>>stumbles/bucks. The truck seems low on power in overdrive but when it
>>>>kicks down, it seems to be ok. I have changes plugs and fuel filter.
>>>>No trouble codes or check engine light. The dealer was unable to find
>>>>anything wrong...it was working well when I took it in. Any Ideas? I
>>>>can recreate the problem by holding the brake and throttle, loading the
>>>>engine. Mostly this is noticed under 1500 rpm.
>>>
>>> This recreation surely sounds like bad plugs(worn cam symptoms too,
>>>but
>>>with just 68K??). But originals should last 100K w/no problem. And why
>>>could dealership not find a diagnostic trouble pattern when the problem
>>>was
>>>being recreated? You DID install a proper set of AC's didn't you? s
>>
> Hey Scooter, I know the AC's are quite expensive (the platinum tip is
> called for, isn't it?), but often perform significantly better than
> non-AC's. HTH, s
>
>

I have had nothing but good luck with the Bosch Supers, but I've been
told that the more expensive Bosch Platinums don't work well at all,
especially if fouled. My info is a couple years old, don't know if
they've fixed them or not. I don't drive any really exotic machinery,
so the regular Supers are still working for me.

nate

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