No power up top

[turboost]

I have had this problem for a while now. When I go about 1/2 throttle the car seems to pull hard but when I go more than that and really put a load on the engine it acts as if there is about 10-15* of timing being taken out but the SM is only showing anywhere from 0-3*. The car just seems to stall for a bit and then comes to life and then stalls again (when I say stall I mean feels powerless).

I have changed the fuel filter, plugs, wires, tested the coil pack, set the tps, tried it with the dump open (no cat), played with some of the settings on the ME a bit. Does anyone have any suggestions? I haven't rpl the MAF but I don't know if it would cause a problem like this. Thanks for any help.

 

[2QUIK6]

If you have never changed the valve springs at 131k miles, that definitely is not helping. The stock ones are worn and weak at only 50k miles on a 15 year old car.
That would definitely be a good investment on a car with that many miles and is rather cheap compared to the results you will see compared to other mods.
I would first tune to get 0 knock at 15# of boost, that takes the spark retard out of the equation.
Check to make sure you are producing a # of fuel pressure more for each # of boost from the "line off" pressure.

 

[soonergn]

I second what 2QUIK6 said. Also you did not mention what your boost is doing while this is happening. It could be a problem with the turbo itself. If it has problems making boost then it could be bad.

 

[crazygn]

How do your hoses that hold the intercooler pipes look, maybe one is leaking under high boost.

 

[turboost]

The valve springs have been rpl. I have checked the FP under boost and it is working correctly. All the IC connections are pretty secure but I'll take another look at them. The power comes up strong but then disappears and comes back. The boost stays pretty consistant. I will try and remove some things out of the equation by removing the volt booster and see what that does b/c the problem seems to occur around 9psi and up but no specific amount of boost. Any other thoughts? I appreciate the responses.

 

[blackbuick87]

Sounds like it is not getting fuel. It has power, runs out of fuel, dies, fuel pump catches up, car speeds up again. Is that what it is doing?

The sock on the pump could be clogged with rust and dirt, or the pump could be weak

 

[TRBON8R]

At first I was thinking valve springs like some others mentioned but since you replaced them I'll second what Bob said. I'd start looking at a fuel delivery problem.