Bigger Injectors ??

[wing3r09]

Hope this is in the right forum, and hasn't already been answered.

I have been noticing when I am driving, that when pulling in 2nd at about 6000 rpm i start to notice almost like a hesitation in my car. I'll then shift to 3rd pull again to high RPM and again, it'll seem to be stuttering.

I feel like it could be fuel cut out possibly, where maybe im getting more air than fuel causing a bad burn. If thats the case would bigger injectors be the solution? If so how big should I go? Do i need a bigger fuel pump? Would i need a 3 bar map sensor?

Thank you guys for your time!

[Sean485]

If the car is stock or nearly stock then factory injectors are fine. Putting in bigger injectors requires tuning as the ecu does not know that the injectors are larger.

Fuel cut is a very harsh stop, stuttering at high rpm generally is caused by igniton issues. Bad plugs/wires, possibly bad grounds or coil packs.

[wing3r09]

It is nearly stock, i haven't done much to it, FMIC, Hard piping, BOV, Tubular Ex Header, Full 3in Exhaust.

The wires/plugs were replaced not to long ago, could be the coil packs though. Is there a way i can check them, or just have to buy new ones?

[Sean485]

What type of plugs and wires did you use and what gap? You can check the packs for corrosion by looking inside the towers. They can get heat cracks and the way that I test for that is to start the car at night, or a dark garage and use a spray bottle to wet the coil packs down a bit and look for arcing.

[MindBlowin03]

Have you done a boost leak test? How about a datalog to check for knock?

[wing3r09]

Sean485 i believe they're both NGK, also i did not do replace them the previous owner did not long before i purchased it, so i do not know the gap :/

MindBlowin03 I have not done either of those. I have a Boost leak tester, just have not done one yet.

[Sean485]

Check plugs for thier color, condition and gap and do a BLT then come back. There is no point in us giving you possible problems if they are not physically verified before saying 'nah cant be it cause so and so did this or that'.

[nettslash]

Check your resistance at the coil pack. I am sure you can find a guide by searching, or using a Haynes/Chiltons manual. If you don't know when your plus/wires have been changed, its not a bad idea to change them out. Also check to see if your coil pack is arcing. I had a small chunk somehow missing from mine that I didn't see until after I pulled the pack itself. I also had VERY similar symptoms, as to what you are experiencing, and this was the problem.

[NEWTODSM97GST]

check your o2 sensor aswell.

[SLEEPS]

^ For what... what should he be checking the O2 sensor for exactly?

[dskolevo]

I had an issue kinda like this, only stuttered after about 5k under boost, with no boost ran fine. Check for boost leak once, its a long shot but i bought all new ignition stuff and still was have bad shuttering found a bad leak on one of the couplers now she runs fine.