ok so check it out like the title says i have a BOOST probelm and i cant frigure it out so if anyone has any ideas let me know.

ok so i got this 97 audi a4 quattro turbo 5 speed about a year ago it had a bad wastegate so my friend put a spring on it and it ran great no spikes at 9 psi for about 10 months well i ordered a new wastegate and just put it on and it hits 7 psi just like stock i think, anyways so i have an MBC and i know you shouldnt up the boost with out the chip and anything thing past 15 psi can put me into limp mode but i just want a few more PSI till i can get the chip, well i installed the MBC and first i unhooked the N75 i think thats what its called and ran it straight from the turbo to the wastegate and it would only it 2 psi no matter what i had it set at so i thought it was hooded up wrong swtiched it around still nothing so then i ran it with the N75 and it would only hit 7psi no matter what so i was thinking that maybe the MBC was bad so i tryed just pinching off the wastegate line and i thought for sure it was gonna spike like crazy BUT NOTHING just 7 psi nothing i do will let it go past 7 psi and it builds boost hella slow now with the blown wastegate with the spring the boost built fast just dropped off hella fast i checked all fittings and didnt find anything vac leaks so far so please let me know what you guys think.

 

Bump!

 

You are creating your own problems and what's worse is that you know you're doing it. Before you blow up your engine due to detonation, remove the MBC and re-install the N75, and remove the aftermarket waste-gate spring and replace it with the stock one.

Save for a chip. It's a lot cheaper than having to replace valves, pistons, or a cat due to misfires and you won't need to screw with a MBC or waste-gate springs.

 

well here is the problem with that the SPRING was on the OEM wastegate the was blown and it was on there to make it work that is why i had to replace it so i cant take off the aftermarket wastegate my real Q? is with the wastegate vac line plugged off so that there is nothing there to make it open how in the heck is it still only reaching 7psi max

 

its probably a 7psi spring. if there is no vac line going to it, then there is no pressure source to keep it closed while under boost.

you shouldnt up the boost AT ALL on stock software. more then 1 bar will throw you into limp mode, yes, but 13psi is still probably dangerously lean.

tweaked is correct, you should never just slap a MBC on there and crank it up on a stock tune. a speedtuning chip is only like $250. would you rather spend $2000 on an engine?