i'm diagnosing a problem on this car... and i can't see why it's running the way it is. need help!!!

symptoms: the car under full throttle will not go past 20 mph's. under partial throttle is a little better. No matter what, neutral, park (it's auto), will not rev past 4500 rpms. basically from 1000-2000 rpms it's fine, under full throttle, but after it bogs down and feels like it's hitting a fuel cut, or limiter. Under partial throttle it can go past 2000 rpms.

The turbo is really really small, at idle it seems like it's spinning at the max. really stuck here...anyone with any ideas would be greatly greatly appreciated.

I'm going to hook up a air/fuel gauge to it today to see what is going on in that department...but doesn't look promising

does the obdII computer have anything to do with it?? i dunno, going out on a limb here...

 

Is your car throwing a check engine light?

What this sounds like is your MAP sensor is seeing boost and cutting fuel. You said that your car cuts out pretty badly under full throttle (where boost is made) which leads me to think this is probably your problem. You are obviously making little or no boost in part throttle so that's why the problem isn't as bad in partial throttle. If the turbo is very small boost can develop when in neutral.

Anyway check your check engine light first and see if its on. Hope this helps.

 

there is no check engine light. I have check valves. Under full throttle, there is 5Psi of boost constant.

So what does it mean if it develops boost in neutral? would that affect anything?
i'm so lost

 

welps, found out what was goin on...not ENOUGH check valves... for some odd reason it didn't throw an engine code. It just pulled timing, and fuel. :T weird...anyways...thanks for the info tho made me think twice about the map n stuff

 

That is strange that the computer didn't throw a code. Well at least the problem is fixed. If you run into this problem again you may want to think about buying a missing link instead of using check valves.