I do have denso fuel pump right now and i don't think my ecu is tuned for after market pump...

whats the limit of stock fuel pump??/

thanks

 

You don't need to tune your ecu when adding a larger Nippon Denso pump.

The stock should be able to handle whatever the stock injectors can handle. From what I've seen, there isn't much benefit to upgrading your fuel pump if you still have the stock injectors. Going to larger injectors requires upgrading your fuel pump to be safe.

 

I have one of those remapped ecu (XS eng).
I figure my ecu increase inj duty cycle and work with stock pump to make my car run rich so it'll be safe for my mods..
but with denso pump i got right now makes car run rich as hell cuz inj duty is still high and denso pump pumps more fuel... thats why i want to try stock fuel pump.. also thinkin about SAFC to take some fuel out..
My dyno number didn't impress me cuz car was running very very rich..

correct me if im worng.

 

Your problem is the tuning of your ecu. It has little to do with the fuel pump. The higher flowing fuel pump has the capability of flowing higher, it doesn't necessarily mean it's flowing a lot more. The injector pulse characteristics determine how much fuel is combusting and that is controlled by the ecu.

The S-AFC does not allow you to remove fuel, only add it. It also has very crude resolution and does not have air temp or water temp correction factors -- dangerous IMO.

Is your ecu "tuned by mail"? If it is, that is your problem. To be safe, they just make it run really rich. You'll either need more air flow mods or you need to get a stand-alone ecu that you can tune.

 

okay im so confuesd now few people on board told me that safc is good way to take fuel out but lousy way to add more fuel....

more air mods such as???
should i just run 20 psi on turbo and see it will lean out or not?? lol


j/k

 

My mistake, you can reduce fuel with the S-AFC, however my other statements regarding it are true.

What mods do you have on the car right now? How much boost are you running? What is the ecu supposed to be tuned for?

Air flow mods are things like intake, intercooler, Efini y-pipe, downpipe, midpipe/hi-flow cat, and cat-back exhaust.

 

done all that u listed...
mp,dp, Smic, intake, stock twin @10-12 psi
and my a/f ratio was wayy off from dyno chart.
ecu is tuned for 13 i believe.

 

I agree with Ryan. The bigger fuel pump will supply more volume (if needed), but as long as your FPR (fuel pressure regulator) is working properly, there will be no difference if you go back to a stock pump because the pressure will stay the same. The problem is in the tuning of the ecu. It sounds like you have the right equipment for a good running car, you just need to dial in the ecu fuel maps.

Jeff

 

that is true...
hmmm

 

You need a better ecu or a stand-alone like the PFC. There's really nothing else you can do at this point that is going to be safe and reliable.

Post a scan of your A/F ratios if you can. If not, post what the values are at each 500 rpm or so. I'd like to compare it to my stock ecu readings.

 

don't need to scan.. its below 10 and it won't show any number below 10..
guy work in dyno couldn't fig out how to read RPM on rx7

Its running rich as hell..dyno guy said car won't rev up in high rpm while he was doing 4th gear pull.

 

Perhaps you have another issue entirely then, maybe an injector is sticking open or something of that nature. Sorry, but I think you need to start looking for other causes than your ecu.

I'm a little surprised by the ignorance of the dyno technician....

 

How u get RPM reading on dyno? Where to hook up those thing???
I kinda wants my Tq number and if i get SAFC it will be safer and easiler to tune with RPM reading.. my techinican tried to hook up rpm reader thingy to plug wires but it didn't work..