Temporarily going unboosted, fuel pressure help

NYSpeed Automotive
1

Hey guys I need a little bit of help for a starting point at where to adjust the fuel pressure down to. The car is a 99 maxima 5spd and was running a Vortech V2 s/c kit with a 3.125 pulley, walbro 255gph pump, sard fpr, vortech fmu (8:1 disk i believe) and 370cc injectors. That fuel pressure was ~40 at idle. I have had to remove the supercharger for a short time because I am doing work on another motor, and need to get this fuel pressure down lower for a relativley stock maxima aside from exhaust and intake mods.

Stock injectors are 260cc and 34psi at idle. It’s running way too rich, and I am not sure how low to go anymore considering everything has been upgraded. So what would be a good fuel pressure to set it to? Or how can i figure this out.

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moved to Tech Discussion

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Okay to make the 370cc injector perform like a stock 260cc injector you would have to take the fuel pressure you run currently and drop it to 20 psi via my injector spreadsheet. Usually fuel injectors are not going to have a great spray pattern at that low PSI and will probably not atomize the fuel good. How about putting the stock injectors back in? That would be the better way to go

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I could put them back in, I just didnt want to take the IM back off since I already dropped a new motor in and got everything up and running. But if thats whats best, then I may do it since its not that difficult just a pain.

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What is IM?

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INTAKE MANIFOLD…the upper Intake manifold has to be removed to replace the injectors