Hi I have a r53 and my afr is going lean at wot. It's running 19.0 + I can't tune it until I fix it. I've replaced the fuel filter, checked the fuel lines and checked the gas cap. It has a head with bigger valves and it's ported, sprintex supercharger, 550 injectors, dinan intake, mega mini cam, and a Detroit tuned bypass valve. Any ideas what the problem could be?

 

Yeah it's not tuned for all your stuff..you need someone to remap the AF maps.

 

yup you need a tune. if you have one allready it needs to be fixed but sense you didnt say you have one you need one. and its the only way it will be fixed.

 

It's has a tune but it's a basic tune and they can't proceed with a better one until I figure out the problem

 

And I keep fouling o2 sensors

 

Might want to stop doing WOT until this issue is fix. May i ask who gave you a basic tune for your mods?

 

I have stopped wot and the tune is Mynes or bytronics

 

Did you replace the Fuel pressure regulator on the rail when doing the injectors ? It has a small filtering screen and diaphragm, works under vacuum pressure maintaining the proper fuel pressure in the rail when at load.

Also, maybe you have exceeded the capability of the stock fuel pump.....those are some heavy breathing mods for a stock pump to keep up with. Dinan sold one which offered higher performance than stock.

 

Dinan discontinued mini parts do you know anyone else that makes a upgraded fuel pump and a upgraded fuel presser regulator

 

I've been using the stock fuel pump for well over 125k miles with the 550cc injectors with NO issues, unless it's bad thats not your problem.
First check for a major vacuum leak, such as a disconnected line, esp. at or near the fuel regulator, the ECU will compensate for such a leak and it won't be real noticable in your everyday driving, I had a line come off after doing the VGS mod and the AFR would run about 16+ at WOT simply because the regulator wasn't getting the proper vacumm to compensate for demand.

 

^^^+ sounds like a very good advice since you did all that work to the drivetrain.

 

Normal driving it runs 13 to 14 and I've checked all the lines