1997 Eclipse GST Turbo unknown acceleration problem

[Vincent16]

So I recently put a new engine and wires and hoses in my eclipse (as a note, my turbo is aftermarket and fairly bigger than the stock one). A couple weeks ago I took off from a light and as I was accelerating there was a kind of pop. Suddenly all my acceleration stopped and my car started slowing down and the rpm's went down as well. Ever since then my acceleration has been limited. I have a boost and vacuum gauge in my car and the vacuum has no effect but when I get to around 2 pounds of boost or pressure the acceleration stops and I can hear what sounds like misfires. popping out of the back and it doesn't sound too good. I initially thought it was a boost leak, but I checked almost every hose, I don't believe I missed one and there was no leaks I could find. Also when I accelerate and let off the gas I can hear the boost pressure valve open and hiss. It does it louder when I get closer to 2 pounds of boost. It mainly happens in first and second gear, while it does happen in third, fourth and fifth gear are not affected by the deceleration. As an example when I am in first and accelerate and hit the 2 pound mark the car stops, leans forwards and pops if I continue and don't change gear. Any ideas what it could be? I also have 2 codes telling me there are problems with my 02 sensors, I'm not sure if that is it or something I am overlooking. I have never had a car with a turbo before so I am not so much knowledgeable in that field. Any help is much appreciated. Thank you.

 

[emeracing]

Check your plugs I fouled mine out and it did that until I replaced them.

 

[Vincent16]

Check your plugs I fouled mine out and it did that until I replaced them.

I will check but I had all new sparkplugs in it anything else it could be?

 

[Bo0sTeD 4G63]

Does it only happen when you boost?

 

[DSMrightontime]

"... I was accelerating there was a kind of pop. Suddenly all my acceleration stopped and my car started slowing down and the rpm's went down as well. Ever since then my acceleration has been limited. I have a boost and vacuum gauge in my car and the vacuum has no effect but when I get to around 2 pounds of boost or pressure the acceleration stops and I can hear what sounds like misfires. popping out of the back and it doesn't sound too good."

I'm pretty confident you have a sizable boost leak. Did you do a boost leak test, or just a visual check?

 

[Vegas Smith]

I agree^^, sounds like you just did a visual/minimal leak test. Look up how to do it correctly and I think you'll find a big boost leak.

 

[Bo0sTeD 4G63]

It sounds like a boost leak I would do a real boost leak test and lost your results.

 

[zedicus]

boost leak test, however if it is not a boost leak, you might have blown the seal out of the fuel pump hanger. these cars will run up to boost on almost no fuel pressure but as soon as any boost happens it will fall on its face if that seal is messed up.

take the return fuel line off and the vacuum line off the FPR. hook a wire to the pump activation lead while the car is not running. if fuel flows out the return feed that is good. if no fuel comes out the return feed, or fuel comes out the vacuum port, that is bad.