Need help with my Turbo.....

[honda1982]

So my turbo has been acting up the last 2 week and I don't know what it is. My GSR has been running Neptune for the last 4 month with absolutely no problem until now. If I half throttle on the gas pedal the boost will slow goes up til my max boost 11psi like normal but if let said I full throttle on the gas when I'm at 1psi,4psi,6psi,8psi,etc... the engine start to back-fire and make that buuoopp, boooup,boooup sound and the needle on the boost gauge jump up and down with 1-2psi radically. I don't know how to explain this but it feel like my external wastegate is openning,closing,openning,closing when I slam the gas and the boost gauge only read 6psi (it is set at 11psi).

I took the MBC off today and it solve the full throttle problem mention above But this time when I hit the WG spring rate (6psi) the engine make that buuppp,buuppp,buuupp sound again. So now I'm thinking the WG (cheap Tial knockoff). So anyone with alot of turbo knowledge please chip in. I willing to pay some money(I'm not rich) to help me solve this problem.

[floored4door]

When was the last time you changed your plugs?

[honda1982]

last week, gap it to .030. new spark plugs, wires,cap,rotor.

[honda1982]

I'm thinking maybe it my Ignition coil, I haven't replace them in a while now. Maybe that's what causing my backfires under boost..

[Zach]

did you change anything right before it started happening?

[honda1982]

nope, none nada... maybe I clean out my air filter but that's it. the car start and run fine just that at full boost it acting up.

[boostedEG]

when my coil started to go out on me it was backfiring (only under full boost) which made a very loud poping noise in the exhaust (open DP at the time).

sounds like it could be the same issue your having.

i replaced my coil, but a couple weeks later the problem came back. havent tried to fix it yet... if the coil went bad again i need to figure out why...

[Weston]

It doesn't really sound like a wastegate problem. I'd check out the ignition and fuel systems, as well as the MAP sensor.

[servion]

Sounds like an ignition problem to me. Last things to try are the coil and the ignitor. I have personally seen this happen multiple times due to a bad ignitor. Give me a call if you need anything :)

[honda1982]

Thanks guys for all your help. I'll order the coil and the ignitor right away since I haven't replace them for ages. Thanks Jeremiah,Weston,and Jeremy.

[12seccivy]

Sounds like an ignition problem to me. Last things to try are the coil and the ignitor. I have personally seen this happen multiple times due to a bad ignitor. Give me a call if you need anything :)
I too have seen a bad ignitor kill a couple of new coils,Not sure why,but replacing both coil and ignitor at the same time is a good idea...:)

[honda1982]

UPDATE:
It was the igniter. I replace both the igniter n coil and the car is back to normal. How I miss my BOOST.