Just purchased the Hypertech Programmer And Messup Up My 03 Silverado

[03-Silverado]

Hello,

I just bought the Hypertech programer for my 03 Silverado with the 4.8L engine. I read the instructions to tune my truck and did a very basic tuning such as...

87 Octane Gas
Shift Firmess On
Rev Limiter 5500

Shift Points....
1st Gear +3
2nd Gear +5
3rd Gear +8
4th Gear +10

That was all the changes I made to the tuning. All I currently have is the 40 series flowmaster dual exhaust, but everything else is stock.

When I accelerate in 1st Gear... my truck revs past 5K and will not shift out of 1st gear until I release the pedel, then it pops into 2nd. While it is stuck in 1st gear it makes a popping sound under the hood which scared the heck out of me.

I pulled over and returned everything to stock. I then reprogrammed with no modified shift points and the problem doesn't happen anymore.


Can anyone recommend shift points for the 4.8L engine, with only small engine modifications?

Best Regards,
Ryan

[buttnekked]

check out the first sticky. It's for a 5.3 but this should give you a working starting point.

[03-Silverado]

Originally Posted by buttnekked

check out the first sticky. It's for a 5.3 but this should give you a working starting point.

I was just looking at that... It was later mentioned that it was for a highly modded engine, and all I have is an exhaust system

I will give it a try...

[nineball481]

sounds like the rev limiter is set too low, compared to the added mileage you set for the 1-2 gear mph. Try raising the rev limiter to 6000 or lower the mph for shifting.

[03-Silverado]

Originally Posted by nineball481

sounds like the rev limiter is set too low, compared to the added mileage you set for the 1-2 gear mph. Try raising the rev limiter to 6000 or lower the mph for shifting.

Makes sense... I guess the extra 3+ mpg will raise the RPMS significantly in first gear. It sure was wierd hearing it stick in 1st and making a popping sound coming from the engine somehere... I've have to try again with a higher rev limiter setting...

6K for the RPMs sounds pretty darn high for a V8... but I guess as long as I don't sit at those RPMs then I should be fine...


Thanks for all your help

[grego12r]

hi incres rev to 5900 or 6000 or lower the shift to 1 or 2 +
an my 2000 5.3silv
1/2 3+ 2/3 8+ 3/4 10+
rev 6000
the shifting only work good from stop like when you drag race its gone hold longer shifts like from 1 to 2 or 2 to3 3 to 4
i thing your rev was to low or shifting from 1 to 2 to much lower them
to 1+ or 2+ and you see
my silverado shifts 1 to 2 at 5900rpm
if rev is to low its not gone shift
or IF shifting pints are to low
i hope that halp you

[03-Silverado]

Thanks for the reply...

I changed the shift points to...

1-2 +1mph
2-3 +8mph
3-4 +5mph

Rev Limiter -> 5900



Performance gain was noticed... Do you think I can change my shift points even higher and raise my limiter to 6K? Is that really safe?

[Slowprocess]

Originally Posted by 03-Silverado

6K for the RPMs sounds pretty darn high for a V8... but I guess as long as I don't sit at those RPMs then I should be fine...

Heh, heh... Tranny didn't shift on me one time tonight and I hit the rev limiter. I checked the memory on my tach, and it was at 7000. Now that will scare the hell out of you!