[Irace86.2.0]

Originally Posted by kobet7

I Installed the kit around June and was having no problems. Then about 2-3 months ago I started getting poor performance (hesitation) and backfire while accelerating under boost. This led me to change the spark plugs to the ones mentioned above and changed the MAF sensor with a new one which fixed the hesitation. But now I am left with the car backfiring and misfiring I am assuming because the car will lose power at max boost (14 PSI at the time)

Why did you change the spark plugs and MAF? Just rolling the dice in hopes that this would fix the issue? What was the condition of the spark plug terminals? Was there any damage, discoloration, deposits, etc? The question is what changed? It was running fine with the 14psi spring, which, unless you are on E85, is too much boost for the stock block on pump gas and an E-tune. What is your duty cycle on your injectors? You say you were running rich at this boost, but how rich is rich to you because if you are on pump gas, you would need to run pretty rich with pretty poor timing to avoid knock at 14psi.

So the car had hesitation and misfiring and backfiring while accelerating on boost? Did you log these events at all? Are you sure you were actually accelerating? Is it possible your foot was on the pedal, but the failsafes closed the throttle body or cut ignition because of a bad condition, and then you had a backfire? It seems to me like a backfire under WOT boost would be impossible without ignition failure from a bad coil or something, or from a bad injector harness that temporarily lost power. I feel like if it was a fuel pump o-ring seal issue then the problem wouldn't be intermittent. Not using enough o-rings or having it fall apart to the bottom of the basket tends to just make the car unable to run.

Originally Posted by kobet7

I actually was curious about my WG because I noticed I was hitting 1.83BAR when the car was first installed but was ensured by fullblown that they put a 7PSI spring. Well I pulled the WG to check and come to find out I had a 14 PSI spring the entire time. I changed it to a 7PSi spring which for now solves the problem but I am basically nerfing the car for it to not blow up. I believe I will run into issues when I meet with my tuner for a 8,10,and 12 psi map.

You say 1.83 bar; that is absolute bar, right? If so, that is 12 psi (0.83 bar over atmospheric). That seems reasonable if you believed the spring was roughly 14 psi.

Originally Posted by kobet7

Looking at the logs it looks like I am running lean towards the higher RPM range but it goes back to being normal once I hit a certain RPM which is strange. The log from 11 June shows when the car was running rich (I had a boost leak at the time). The log from Nov 18 is a Revision to the tune that Fullblown gave me back in june to try to fix the new lean issue problem to no avail. With the 14 PSI spring still installed, I will get backfiring and loss of power around 4000RPM which is close to full boost and is running lean. The new log from Nov 27 is after I put the 7PSI WG spring in shows that the car isn't having problems but is running lean.

Do you have these logs? How lean? How rich?

Originally Posted by kobet7

I had the shop check for vacuum leaks and exhaust leaks and they discovered a few leaks at my piping and blow off valve and fixed them. At this point I am pretty much stumped as to why the car is backfiring and loosing power once I reach a high boost level. I removed and installed the fuel pump multiple times and put an entirely new housing assembly as well. The fuel injectors were removed and there were no visible clogs or damage and the o-rings are still in pristine condition. No fuel is leaking from the port injectors.

It is just strange because even with a 14PSI spring, the car was not running lean and was actually running rich in june but has now became lean.

Do you have antilag?
What is your timing set at?