How does a fuel pump rewire affect injector duty cycles?

[RMeadows]

It would lower them, correct?

The reason I ask is because I have 850's and i'm currently seeing about 95% Duty Cycle at 7K during WOT pulls on my Evo3 16g. I have a chip to compensate for them and i've run a boost leak test and found nothing other than a small leak at the Throttle Body which as I understand it is pretty normal. Is it because my injectors are so big that the pump just isn't keeping up and so the IDC's are sky rocketing? It's a 255HP.

 

[GVR4592]

It's either insanely rich or not accurate. Additional fuel volume isn't going to change IDC's.

 

[D_Eclipse9916]

Do you havea an AFPR on there? Typically dont see that high of IDCs unless you have a serious problem. Check your base fuel pressure, and if you dont have an AFPR, get one.

A fuel pump rewire just provides more "clean" power to the fuel pump allowing it to work closer to free-flow spec. Its like trying to power your subs with a weak battery, itll work, just wont work as well.

What are you using to monitor your IDC?

 

[RMeadows]

Base FP is set at around 37PSI with the vacuum line disconnected. I just read on VFAQ that you should plug the hose when you disconnect it to get an accurate reading? Maybe that is my problem? I simply disconnected it and set the FP. Didn't plug the line. dunno.

I'm using a logger to check the duty cycles. My Fuel trims are all within a good range so it really doesn't make sense to me.
low=107
mid=98
hi=102
The duty cycle just shoots up way too high when i'm at WOT. It's at maybe 2% at idle. Then slowly increases as the revs go up but as soon as boost comes on it shoots up to like 40% and never looks back.

 

[Echo5Zulu]

Man that pump and large injectors should support that 16g no problem how many pounds of boost are you running? Have you tried bumping up your base fuel pressure. You can check out some internet fuel calculators to see what fuel pressure you should run for the horsepower you want to make.

 

[JayRolla]

Hows the rest of the log look, do you have a wbo2. Are you adding lots of fuel at all.

 

[zippyshoe]

A fuel pump rewire will have zero affect on your injector duty cycles. Your IDC's are determined by the ECU based primarily on what mass airflow it sees. You may want to try logging mass airflow (lbs/min) to see if these values seem reasonable for the amount of boost you are running. If these readings are much larger than expected, then I would take a closer look at your airflow sensor - it may be defective or not calibrated correctly.