At what point is it wise to replace / upgrade the fuel injectors? My 2003 1500HD has right at 200,000 on it. The motor is out being rebuilt to 370ci, Mahle LQ9 style flat tops, 243's slightly massaged with 222/226 EPS cam, and of course new oil pump and timing chain. Should I stay with stock injectors till they crap out? Should I replace them with a set of flow matched injectors and or upgrade to different injectors all together? and if so, how do I figure out what size? Marine or not? E85? What brand or does it matter?

 

If your stock injectors are still working and not maxed out I don't see any reason to upgrade them.

Best way to tell is by scanning and recording the Injector Duty Cycle. Do you have any tuning/logging software or know someone that does?

If your stock ones are at their limits with the changes then new ones will be in order. How big you go depends on pocket book and what your plans are in the future. I'd rather go a little larger than what I would need just in case I want to go even bigger down the road it's one less thing to worry about.

 

No scans or logs at this point. The motor is out being rebuilt. Just looking for opinions before I put it all back together. Don't really know what the expected life of a stock injector is with 200,000 miles on them. At the very least I would think a good cleaning and flow match was in order but don't want to do this if they are on the verge of crapping out on me.

 

The delphi Marine 44lb injectors are perfect for that combo.

 

Thanks man. I will look into these... Are they a direct fit or will I need to adapt them in any way??