Injector Duty Cycle at 100% +/- 3%

[ULOSE2A6]

Need some help figuring out if the VE Tables (or what else) will have anything to do with the injector duty cycle being maxed out.
Senario: 96lb injectors showing 100% +/- 3% between 4500-5700 rpm (top of 3rd gear). VE numbers are around 94 in that same range and there is O2% correction of approx +25%. Actual A/F is right around the 11.5 ratio. Fuel pressure was holding steady for the boost being run, but we have not yet verified if the 2nd fuel pump is coming on as it should. Any help you can extend to this would be helpful and appreciated. Thanks.

Regards,
Shev.

 

[TurboBuRick]

I would say fuel pump is laying down. Need to verify if the other pump is infact working. I would bet it's not.

Just my $.02

 

[Mad_Trbo]

What sort of ECM

What are you running for an ECM and do you have the correct injector size programmed for your ECM?

 

[ULOSE2A6]

Running the FAST bank to bank and the ECM does have the 96lb injectors programmed. Thanks.

 

[ULOSE2A6]

Any other suggestions? Thanks.

 

[Chuck Leeper]

96# injs ...fuel psi is holding w/ the boost being seen...
Lack of a second pump would likely show a drop in FP, if in fact, the O2 correction was using the DC to keep the A/F in line.
Boost is?
Has the system ever been correctly tuned? IE:this is a new problem.
Is this system on 1 of the 12 sec cars you list??
Do you have data logs that you can post for the goorus to look at?

 

[ULOSE2A6]

Chuck L. -
- Boost was 30lbs
- The system is new in the car and we are just now tuning it in. This is why I was thinking that the VE Table amount in the higher RPM range has something to do with the high injector duty cycle %.
- This is not on one of my cars
- I will have to get the logs to post them on here but I have never posted logs on here before so I will try to do that this weekend, plus we will be checking the second fuel pump tomorrow as well.

Thanks again.

 

[Blazer406]

Chuck L. -
- Boost was 30lbs
- The system is new in the car and we are just now tuning it in. This is why I was thinking that the VE Table amount in the higher RPM range has something to do with the high injector duty cycle %.
- This is not on one of my cars
- I will have to get the logs to post them on here but I have never posted logs on here before so I will try to do that this weekend, plus we will be checking the second fuel pump tomorrow as well.

Thanks again.

You guys start tuning a new system at 30 psi... Holy Smokes Batman!

 

[Chuck Leeper]

Kinda..

You guys start tuning a new system at 30 psi... Holy Smokes Batman!

SCARY!!!

 

[ULOSE2A6]

Simmer down fellas, lets keep the drama to a minimum please.
We were running 30lbs when the issues mentioned above surfaced we had been tuning already and running fine with no issues at lower boost levels. Thanks.

 

[Blazer406]

Simmer down fellas, lets keep the drama to a minimum please.
We were running 30lbs when the issues mentioned above surfaced we had been tuning already and running fine with no issues at lower boost levels. Thanks.

I was just picking.... no harm intended.....:redface:

 

[ULOSE2A6]

No worries at all, I know some people get scared when they see the high boost numbers. Just wanna let y'all know that we have already been 135mph with this car without the FAST system and the times in my sig for my cars are at least 7 years old, just didn't feel like updating them yet. I do appreciate all the feedback though and I know that there are lots in the FAST system that can be fine tuned and to learn. Thanks again.

 

[TURBO54]

what is your lbs per hour and the 02 correction? rwhp?

 

[ULOSE2A6]

lbs per hour I assume you mean on the fuel pressure gauge under boost was 73lbs. The O2 correction was up to 25%. We have never had the car on a dyno so no numbers on rwhp. Thanks.

 

[HighPSI]

Unless you're making 1100+hp, you have a fuel delivery problem or you are running VERY rich.

 

[SloGN]

one thing you need to do is verify what the o2 sensor is reading is correct. you could have a o2 going south.

 

[TURBO54]

on your data log you can select it to see how much fuel you are using. If it is adding 25% it could be a couple things. Fuel pumps, did you monitor fuel pressure during the run. Might be a calibration issue. you could send me the log file and gct file i could look it over.

 

[ULOSE2A6]

It was the Hobbs Switch that was bad. We changed it today and injector DC is now back safely down to the 50-60% range. Thanks for all the help.

Regards
Shev

 

[Turbopoul]

What is a Hobbs Switch ?

 

[HighPSI]

It's a pressure switch that turns on the 2nd pump. The XFI has an output (Aux. 2) that will do the same thing.