99 Tahoe shudder starts at 70 mph

[chris peter]

99 Tahoe 2dr 5.7 shudder starts at 70 mph. Runs and idles great but at 70+ i get a shudder that comes and goes. Once and a while it will set a P0300 code but does not seem to be misfiring. I did a all Delco tune up cap rotor wires plugs new coil and ing module. Fuel pressure test all good.
Full throttle runs great no miss. Any ideas.

[j cAT]

Originally Posted by chris peter

99 Tahoe 2dr 5.7 shudder starts at 70 mph. Runs and idles great but at 70+ i get a shudder that comes and goes. Once and a while it will set a P0300 code but does not seem to be misfiring. I did a all Delco tune up cap rotor wires plugs new coil and ing module. Fuel pressure test all good.
Full throttle runs great no miss. Any ideas.

check the distributor shaft/rotor for wobble . over 170,000mi these usually start to wear.

[chris peter]

Thanks J Cat, I was wondering if that would cause the problem. Should I go with any particular brand or just go to autozone.

[j cAT]

Originally Posted by chris peter

Thanks J Cat, I was wondering if that would cause the problem. Should I go with any particular brand or just go to autozone.

go with the best warranty/price.