Boost Problem/po455

[brkwd51]

ok my spicy is consistantly inconsistant. some days it holds boost and some days it doesnt. well recently ( past week or two) is has been spiking to 8-10 pounds of boost then trickles down to 2-4 pounds. whats up with that? it has a solid 20-21 vac. i installed a forge WGA a year and a half ago and i just did the air test and its solid. what could be the problem?

I also have a CEL po455 (large evap leak). could that contribute to the problem? I think i found the source to that problem.. i found a hose that is orignally supposed to run to a black plastic cylinder on the passenger side engine bay, mounted to the firewall. the plastic nipple is broke off of the cylinder so the hose is running to nothing and there is just a hole in the cylinder. Im thinking thats the evap leak problem? and yes... my gas cap is on tight.

thanks for the help guys!

 

[brkwd51]

no help guys?

 

[blackfamilia03]

im having the same problem .. and it quit doing that. and now is taking for ever to spool.. like at 4000 rpm or eve more

 

[brkwd51]

yea man it sucks. my spools on time. it just never does like it supposed to. ive had this car for 2 years and i dont think it has ever run completely right in that time frame. i just want to know what the real problem is so i can fix it before i go to school this fall

 

[blackfamilia03]

i feel u bro .. i just went to the hangouts and sad cuz i know even a corolla could beat me... and when the car was running nice. i would eat g35's . which wasegate u have? u have a boost controll? and u still have the original turbo??

 

[brkwd51]

haha yea im always afraid a car like that will want to race and ill get beat. but i have a forge wga. and the orginal turbo with no boost control

 

[Pez]

check for vac leaks. Check the WGA. if you have a BOV make sure it's closed when the car is idleing. Ive seen the BOV spring get weak and let the gate open a lil bit. That can cause problems with boosting. also check for cracks on the exh mani. That will play a big roll in boosting problems. Thats all i can think of right now.

 

[justanothermp5]

yes, if that hose isnt going to the canister then that is a gigantic evap leak, might want to fix that pretty soon

that might also be your boost problem

 

[Wagonbacker9]

I have 2 words for you:

boost


leak.

 

[brkwd51]

Yea but what is that exap leak really important? like what even is it? but i havent thought about checking for cracks in the exhaust mani. whats the easiest way to check?

 

[dacquesta1]

evap is emission related. could that could cause the ecu to change the fuel ratio's?

 

[justanothermp5]

the line that connects to the charcoal canister is connected to the intake mani, if the intake mani sucks in unmetered air then thats called a vac leak, since u have a turbo car, air can escape from that same place, causing a boost leak

if there is a CEL then that could possibly mean the car is in open loop, which means the performance and fuel economy go way down

 

[brkwd51]

that makes a lot of sense. haha. thanks. but if this were the case, how come my boost gauge shows perfect vac? wouldnt it be way lower with that disconnected hose? and do i have to just take a trip up to the dealer to get a new canister like that?