i just installed a 2.9 pulley and an intake on my stage 2 ss/sc. It ran fine all day yesterday but today when i get on it it hicupps and then takes off. its like it hesitates and then pulls really hard. what could cause this?

 

Well for one, there has been instances where the duty cycle on the injectors is way to high. Not sure if this could effect this or not. I have a friend who has a 2.9 pulley on stage II or I should say it used to be on the stage II tune. His injector duty cycle was 116% or something.

 

What kind of gas are you using?

Try premium, see if that works...

Also one step colder plugs?

 

1 step colder plugs is not a must, however it wound't hurt anything.

Try the following in these steps: No Specific Order
1: Fill up tank with 93 octance gas. (You should be doing this anyways)
2: Change spark plugs to one step colder.
3: Put the stage II pulley back on, and see if it has the same problem. If it does the same thing, you know its not a problem with the 2.9 pulley.
4: Disconnect the battery for about an hour, re connect it and see what happens. When ever I mod a car, I always do this so the computer can re-learn the new mods. Also make sure your intake is installed correctly with no leaks.

 

Any chance you changed the air intake system or messed with it?

 

i run 93 octane. I put a cai on. I found a vac line that is supposed to go to the boost bypass that was just stuck on the end of a bolt. i put it back on a bare nipple i found on the boost bypass and it runs fine now so i was just wondering if that hose is where it is supposed to go?