HELP!!! My car drives fine until I try to go into boost!!!! I pressure checked the intake with 15 psi and found two small leaks... I then fixed the leaks and changed the plugs. it still will not go into boost! Is it my turbo?? it has very little play???
thanks Steve

 

does it stumble when it starts to boost?

I would check REALLY throughly or boost leaks/vac leaks and make sureit will hold pressure.

 

check the hose that goes to the pressure sensor for leakes. i would hope you have an aftermarket boost guage in there. if so does it do it right when you enter boost or at a few pounds. do you ahve a fuel cut defender?

 

I checked all vac lines, pressure tested the intake... what i did was put a rubber cap with valve stem on the turbo and pressurized the intake to 15 psi and i had two small air leaks. I fixed the leaks and pressurized again and no leaks! also changed the plugs and it still runs the same. I do have a boost gauge and the car stumbles at a hair over 0 psi not even 1psi and will not boost!! I do have a RB FCD. could that of go bad??? I would think it would still boost if the FCD was bad??
Thanks for any help you can offer!! Steve

 

just for ***** and giggles remove your FCD and see if it boosts. its worth a try

 

will do

 

Well i unpluged the FCD and still the same! then i parked repluged the FCD and unpluged the AFM just to see what would happen and it was still the same!!! Any other suggestion??? Like i said it runs GREAT !!! under vacuume, the car just will not boost!!! thanks STeve

 

pressure sensor perhaps?

 

can you run the car with out one???

 

ummm, my TII Im not sure about, but I know during some diagnosis on my N/A I ran it with the pressure sensor unplugged to see if I noticed any difference and I couldn't really tell (dry revving though, no driving down the street)

But I would imagine that you should, what if the sensor failed whle driving down the road? it probaly just goes into some sort of limp mode.

But I don't know 100%.......I would say check the FSM, it may have a procedure for testing the sensor, or if you've got a spare, swap them.

 

well i tested the pressure sensor! it is within spec via the FSM

 

hmmm just explain this again for me please.

Revving up the motor:

gauge is in vaccum..start reving..gets to 0...keep revving....goes over 0...:

At that point does the motor fall flat on its face? No amount of mashing the pedal will make it go further?

Does it occur at a certain RPM point or does it occur at any RPM point but only when beginng to go into boost?

 

While im driving the car or reving the motor in nuetral as soon as the pressure gets to 0psi the car will sputter, it wont boost, and it doesnt matter what RPM in in!

 

I stumped......could it be loose clips on the secondaries?

Sounds like its definetly fuel related to me

 

well i dont think it would be loose clips on the secondaries cuase it would do it at the same rpm everytime. the secondaries are triggered by rpm not boost. but this is different.. maybe its computer related...i know nobody likes the sound of that

 

i was thinking maybe bad coil???? or turbo????? i dont know???

 

hmmm....try a different afm, maybe when it goes to pressure, it screws up. just a shot in the dark, for another shot in the dark, check timing, and check compression. also...try removing air filter and rev it while sitting there. i had a motor that was so low in compression it could barely draw air thru an air filter *shrug* atleast i think so. wouldnt rev with it on, would rev with it off....