Hey guys so I have a 2002 wrx the car had the motor rebuilt by previous owner by subaru currently has 45,xxx miles on it. My mod list is as follows I have a vf39 turbo, sti tmic, 1000cc injectors, 255 fuel pump, full catless unequal length header back exhaust system, manual boost controller, open dump waste gate and just recently put a 2006 sti transmission into her. The car was recently retuned and put down 293whp 292wtq on a mustang dyno this was a open source tune so I do not have a accessport or any real engine management or data logging system unfortunately.
Here is the issue: So I get the car tuned things running great did a few pulls to feel it felt great! Few days later I do a pull next thing I know the car makes a pop sound, I let off the gas continue driving from 2500 rpms on the car is just sputtering getting no power running like total crap. I pull over exhaust smells like straight gas, doesn't sound right either. I threw no codes though so I pull it in the driveway and get to thinking so first thought was since it smelt like gas maybe something injector related checked those seemed fine. I pulled the spark plugs they were all fuel fouled now since it was not just one and was all 4 It leads me to believe it is not the injectors pretty rare for all four to go at once, so I replaced the plugs and moved on. So next step did some reading online read some of my symptoms could be from my FPR (Fuel Pressure Regulator) did a test on that totally fine. Next thing I was reading is maybe a leak in the intake or intake manifold a boost leak ect...so I took the intercooler off and the Y pipe along with all the hoses seemed fine. One kind of interesting thing is the recirculating hose (I think that is what it is called) from my turbo to where the bypass valve would be was not attached to the bypass and was actually blocked off by the previous owner. I did some reading and it seems people do that when they go after market blow off valve so I assume it is like that due to the open dump waste gate? In any rate though after looking around I saw no evidence of the hoses being damaged in any way. One thing that was also odd is one of the tubes actually attached to the intercooler had a bit of oil on it but I stuck my finger into the hoses that would attach on and there was nothing. After doing this I figured since I have the intercooler off I may as well clean the throttle so I did that. Re bolted everything on started the car it appeared to be running a bit smoother but still not as it usually would and the exhaust still smelt very rich. I continued to let the car warm up rpms were at around 1,000 gave it a rev and they got stuck at 2,000 so I turn the car off. Fiddle around with the throttle to see if maybe I screwed something up turned it back on reved it some more didn't happen again. Honestly I am at a total loss I don't really know what my next step would be other then to pay someone to do a leak down test manifold and boost but I am pretty pressed for cash as I just got laid off my job, and I spent all this money on the tune.
I figured maybe you guys could help point me in the right direction or give me some ideas of things to further test, I had a buddy who has the tools to do a leak down and was supposed to come by but he keeps putting it off to the point where I am considering just shelling the money out for a shop to do it kind of reluctant though.
I really tried to do my reading and figure this out before posting but like I said I am at a loss and I am no mechanic my dad is pretty good with cars so we were going at it together and are both drawing a blank any idea's, or suggestions you guys can provide would be great!