tuning issues with 5sfte, having trouble keeping a stead a/f Options

[D_Dawg]

So i have a 5sfte and im using a NEO to tune with 460cc injectors. My problem is that sometimes the car runs fine and the wideband reads in the 11's. but randomly the car with run way too high of an a/f ratio. even at idle sometimes i need to take fuel out to get an 11 and sometimes i have to dump fuel in. what could be causing this random a/f issue. my IAT sensor hasnt yet been put into the piping but i doubt it can make that huge a difference, other than that i dont know.

[lagos]

That IAT sensor does play a role in fueling, so I would hook that up before you start any diagnosis.
You also have to keep in mind that the safc is just trying to fool the stock ecu, but the ecu can still adjust the fuel map based on changes in ambient temp, coolant temp, etc..

[presure2]

at idle and low throttle, low load situations, you want the AFR to be ~14.7:1, which should require you to pull alot of fuel to get to.
you should never have to add fuel with the SAFC, i make ~300whp, and still dont need to add fuel.

and yes, the IAT sensor needs to be in the IC piping, after the IC, before the throttle body. like art says, it plays a role in cold/hot temp compensation maps the stock ecu uses.

[D_Dawg]

ok i put the IAT sensor in, and im still having issues keeping my a/f ratio below 14's under load. the safc is set to zero at high throttle at 20% . any ideas what might be the cause

[D_Dawg]

could my issue be related to a bad egr valve? my reasons for suspecting this is a cel code i had before the install that indicated a bad egr valve. i managed to get this cel to go away but never inspected the problem.

or could my fuel pump or injectors be to blame. although i dont think so as the car runs rich acording to the wideband at start up, which is normal. however as the car warms up i am unable to maintain the proper a/f ratio under load.

[presure2]

could my issue be related to a bad egr valve? my reasons for suspecting this is a cel code i had before the install that indicated a bad egr valve. i managed to get this cel to go away but never inspected the problem.

or could my fuel pump or injectors be to blame. although i dont think so as the car runs rich acording to the wideband at start up, which is normal. however as the car warms up i am unable to maintain the proper a/f ratio under load.

By under load do you mean wide open throttle?
If your having lean issues at all with the 460cc injectors at wot I would start looking at somthing else other than the safc.(assuming the safc is installed and set up correctly.) i wouldn't think it's the egr either.
You should be pig rich everywhere with the 460's, to the point of it sputtering above 4000rpm without tuning.
If your getting anything other than that, you have some other issue, whether it's the pump, filter or whatever else.

[D_Dawg]

So, say it’s the fuel pump. How would one go about checking such a thing? I can pull it out but I’m not sure how ill know if it’s bad or not. My injectors were rebuilt prior to me buying them and came nice and shiny and new so I doubt they are the problem. what I don’t understand is how can it be a fuel pump or filter issue when the car runs rich on startup, so it must be getting enough fuel.

My friend recommended I buy an adjustable fuel pressure regulator and simply up the pressure by about 5 pounds and adjust with the NEO from there. Would this be a good solution?

[lagos]

By under load do you mean wide open throttle?

???

This post has been edited by lagos: Nov 26, 2009 - 9:36 PM

[D_Dawg]

By under load do you mean wide open throttle?

???

i mean upwards of 30 percent throttle or so

[lagos]

By under load do you mean wide open throttle?

???

i mean upwards of 30 percent throttle or so

Then the reason why you can't get the car into the 11afr is because thats not where it should be!

Here is the basic idea:
At warm idle, the car should be at 14-15 afr.
During part throttle driving, the car should also be at 14-15 afr.

11 afr should be your target ONLY when you have your foot to the floor and are doing a full throttle 3rd or 4th gear pull under boost. Not at idle, cruise or part throttle driving.