Need new fuel injectors?

[kentjohnson4]

Hey everyone -

I bought my 04 Grand Prix used with about 130k miles. I put new plugs and wires in, cleaned the MAF and the throttle body, replaced air filter, and a new fuel filter as well. The car got great mileage right after the new fuel filter but has since averaged right around 18-20 mpg. The car hesitates a bit when I accelerate and idles a little rough.

I'm thinking that i might need to replace or service the fuel injectors -- but I'm not sure. I wanted to see if any of you had some knowledge or thoughts that you could share with me. Tire pressure is around 35 psi.

[Scottydoggs]

what plugs did you use?

if you used platinum plugs change them out for some iridium plugs. these cars dont like the plats very much.

[kentjohnson4]

Sorry - should have mentioned. I used AC Delco Iridium plugs.

[Scottydoggs]

is your car N/A or super charged? have the lim gaskets been done yet?

you can also check for vac leaks with some carb cleaner. start the car, let it idle, spray the carb cleaner at the vac lines and the sensors they lead to. if the idle jumps up, you found a leak.

[kentjohnson4]

is your car N/A or super charged? have the lim gaskets been done yet?

you can also check for vac leaks with some carb cleaner. start the car, let it idle, spray the carb cleaner at the vac lines and the sensors they lead to. if the idle jumps up, you found a leak.

It doesn't have a super charger and I couldn't find a leak with the carb cleaner. Haven't done anything with the manifold gaskets.