So i have a 1994 z28 automatic with 85k. I took it out on the hiway and as it starts up a new gear at about 100mph and hits 105 exact the car jumps and starts to slow down. Any suggestions, could it be my mass air flow sensor, and would the power programmer fix this problem?

 

i know mine doesnt have a governer, ive been around 150-160 when i still had the 3.42 gears, if your car came with Z rated tires then you dont have a governer.

 

I baught it used with g force tires, what do u think is wrong with it?

 

what are the numbers on the tires ?, i know theyre probly not original and they could have been replaced with lower rated tires, but it should read something like this if you have 16" tires 265/50ZR/16

some cars came with a bigger performance rear gear, some came with the standard 2.73 it was an option in our year, if you have the 2.73 it would govern around 105-110

you may be able to use the programmer to eliminate the limitor, but you may want to spend the money on a quality dyno tune, or mail order tune, they can remove the limitor and give you a much better tune than the power programmer.

 

It sais 245/50ZR 16, how much would a dyno run for?

 

Sounds like your car wasn't ordered with Z rated tires from the factory, and therefore it's speed governed below S rated tires(speed rating of 112, so they govern it at 105-108). You can get it taken off by reprogramming the PCM, either yourself with a Hypertech Power Programmer or sending your PCM to pcmforless.com as 94Z28shaker already suggested.

 

a good dyno tune is around $400 , youd be better off sending in your pcm to www.pcmforless.com

if it sounds like somethings wrong though you may want to get your car scanned for trouble codes before sending it in.

 

ok i will check into that, thanks for all the help!