QuestionMy tbi blazer has a hesitation (sometimes) when starting from a dead stop under normal acceleration, then another stumble
at 1-2 upshift which is very firm (700r4 has corvette servo).The problem is worsened with the a/c on which is worsened more due to a smaller than stock driven pulley on compressor. Other than 10;1 pistons motor is stock. exhaust cat/clear. injectors ok. map, air valve, knock module, tps check ok. fuel pressure 12 psi. i have a scanner but cant get live data from this vehicle. This truck runs very well in open loop (o2 disconnected) with plenty of power.
AnswerDid this truck ever run OK after the mods and before the stumble? Or did the stumble come immediately after the mods?
When you change some things and not others, you create a large problem in calculation within the computer. You have 10:1 but didn't change the valves, cam or reprogram the computer to accomodate the larger pistons.
When suped up race cars of today do anything, they go to a dyno and have their computer tuned in to what they did. You have to adjust pulse width of the injectors. The O2 needs to understand that the HC will be more present. It goes on and on.
These cars today are mini computers. In open loop you have no computer control. You may be better to go with a non-computer controlled system, and a carburateor. Then you can play with this any which way you like.
