Overboost problem?????

[Turbocivic1]

I have my done the basics to the engine exhaust from the turbo back in 2 1/4inch and freed up the inlet with a custom cold air intake and have a front mount intercooler, wasgate line is untouched. Its a T1 engine with a t2 throttle body and a blocked up /removed EGR valve vacum cannister on distributer has a leaky diaphram so have just disconnected and blocked up until I replace it.

now my car seems to just keep on boosting it goes to 10-11lbs and pauses for just long enough to see the pause then heads for the boost cut, I am finding that I am only getting to about 4000-4400rpm in each gear at the most before the boost cut comes in???

Can people give me an idea of what I should be looking for to solve this problem??? I have a spare wastegate diaphram and was thinking of trying that???? ??? ???

[Turbo3]

Have you checked what the actual manifold pressure is when it cuts? Sounds like a sticky wastegate, which normally cuts at 16 psi. My T2 did the same so I tried a proper workshop gauge on it and found it went to 18 before the computer said "nope, thats enough!!"
Try the new diaphram or just check the rod is able to move the gate.

Pete

[Michael]

I too have a civic with similar mods and am having the same problems. I have tried several wastegates, flowed the dump pipe, taken the manifold and turbo off to inspect it, all with no answers. Mine was made worse by the computer running in limp mode. If you fix the problem please post what the problem was.