i got a problem and i was wondering if you guys could help me out... when i accelerate in my car at about half throttle the car is fine and spools up fine, but when i try to accelerate harder my car kinda stutters and jerks like it is cutting out. it only happens after like maybe 4000rpm and when it starts to go around 10psi+. my car is set to run 15psi. i just put new oil in it and it didnt fix the problem... but it needed the oil change. i was wondering if it might be cutting out fuel due to a bad fuel pump or injectors or something in the fuel system, or might it be something else? i was only thinking fuel because it is only under higher boost and hard acceleration (which requires more fuel...) but you guys know more then i do. i am also gonna clean out my air filter tomorrow. its pretty dirty. if you guys have any suggestions they would be greatly appreciated! thanks! oh, and i think the injectors and fuel pump are stock... and i replaced the fuel filter about 30 or 35000 miles ago, so i may need a new one??

 

The default method of fixing this is to do a boost leak test. Boost leaks are always going to happen in turbo cars and should be checked every so often, more often than none.
Try that first, since boost leaks cause more issues than anything else or is hidden by other issues.

 

thanks for the reply, i will go check it out right now. but if that is not it, are there any other suggestions? thanks... i am gonna go check all my lines right now...

 

okay, i checked a couple things... the boost leak... they are all new hoses.. so i checked for loose ones, and or anything obvious on all the hoses, and tried to listen for one to no avail... so i dont think that is the problem. then i lifted up the back seat and when i turned the key forward there was a click that came from the fuel pump... is that the noise it is supposed to make? next thing i am thinking is maybe fould plugs or a miss or maybe bad injectors/ fuel filter. it doesnt sound like there is a miss and i cant check the spark plugs tonight (need to get a socket for em). now i rolled down the windows to listen to it and it sounds like the is a constant da da da kiinda release of air when it is cutting out. at least that is kinda what it sounds like. i dunno exactly how to describe it really... sorry for the ranting... but my head is going a million miles per hour!

 

i did notice that when idling my vaccum is around 15 on my boost guage... i THOUGHT it used to be around 20... what is the right amount of vaccum? cuz i know that if it did change then its a hidden boost leak i need to find during the day. but i am not sure what the vaccum used to be.

 

18-20hg is to spec. I believe it suggests a leak.
Good idea to also check the plugs for it's gap and it's tip for signs of whatever bad, lol. 15hg is low for stock motor.

 

okay, here is the scoop... there was a boost leak, a line was disconnected. so i connected it and checked them all. the vaccum is now at 15. it was actually at 18 and when i connected the hose it went to 15. i was confused, before i MODIFIED my car it was at 20 and after it went to 15 (this was when my car ran okay) i was just confused. right now i have intake, headers, 3 inch catback, ported aftermarket dump pipe, and a 16g turbo set to 15psi. so this brings up a new set of problems, if i am at 3/4 throttle the car boost great but when i go WOT it does it after about 10-12 psi. the cutting out. could it be that i dont have a mbc (i had one b4 but removed it.) also i have a stock bov. could getting those be the fix of my problems? cuz it seems as if the bov may not be able to hold the pressure and possibly the removal of my mbc allow the boost to go too high for the stock bov to handle? i know it is a new set of prblems... but i just remembered that might be the cause. if so, i may just purchase a bov and mbc this weekend and see if it fixes it... but b4 i do that i would like reccomendations. thanks!

 

sounds like not enough fuel for the amount of air being forced in, is that the big 16g or the small 16g, i remember reading the big 16g should have the red injectors used with it, i think they were 500cc?
maybe fuel filter is getting clogged?

 

Also what are you reading boost on? I know stupid question but I want to make sure you're reading on an aftermarket guage NOT a stock one. The are electronically controlled by the amount of air being taken in. The ECU sees how much air passes the MAS and then calcs the approximate boost fromt hat. Then it sends the electrical signal telling how much to the electronic stock guage. Aftermarket guages run of the actual boost and vac therefor reading correct pressures. Something to think about

 

it is an aftermarket boost guage and the turbo is a big 16g.