I started my s10 the other day, and it wouldn't stay constant, I now have to keep on the gas a little (mind you, it's an automatic) so breaking at stop lights/signs is a job and a half. I replaced the fuel filter and pump and it's still sputtering. Is it the injection system maybe?

 

Maybe... Could be a lot of things though...
Lets start with the specifics on the vehicle (year, model, drivetrain, and any other options that may be pertinent). Once you post this information, I will move your thread into the appropriate tech section. In the future, please read the forum descriptions as detailed on the homepage & choose the section that best matches the topic of your post.

Is the CEL (check engine light) on?
If so, what are the specific codes that are stored/pending?

Did you test anything before replacing the pump?

When was the last time a tune up was performed (plugs, wires, cap, & rotor)?

Have you cleaned the MAF sensor or EGR valve (depending on what year you have these may or may not apply)?

Please answer ALL of the questions when you respond. They all help to point us in the proper direction for getting to the root of your problem.

 

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what kyle said...