04stangman

Hi guys I need some help diagnosing an issues that just started today.

I have a 2009 Shelby gt500. She only has 20,000 miles on her and I put everyone on her, she has always ran strong. Yesterday morning I decided to play with another stang on the freeway. I have her on cruise doing at 64, I down shift to 4th gear...hit the gas and my car seems like it lags or looses power, my rpms raise about 2500 up about 5000 then my supercharger kicks in and the car speeds up.

Now after I come home I tried to disconnect the battery and reset the system and it didnt do anything. I checked all the lines I could.... and I looked the whole engine over. I cant find a thing.... my check engine light isn’t on.. the car seems to run ok until I press the gas pedal to engage the supercharger.... now my rpms raise, the supercharger makes the winding sound then the engine rpms go down and I cant accelerate very fast.

So After That battery reset didn’t fix the problem.... after that test drive me check engine light comes on. I pull the mass airflow sensor thinking it might be dirty and causing false readings. I pull it out, blow it off with some canned air and drive the car to work this morning. Still the car drives and acts normal, until I try and engage the supercharger. The check engine light is off now though....

ziperhead

See if you can retrieve the code that set your check engine light on. If you do not have a device to do this most auto part stores will read them for free.
Just a thought, check your inter cooler circuit and ensure you have flow. When your car has high IAT's it will run like a dog

04stangman

Thanks bro, any more good ideas?

siggyfreud

Get that code. Your car is trying to tell you something. Could be fuel or boost related.

04stangman

Get the code, gotcha. Are al lthe codes stored in the cars computer, or only when the light is on?

siggyfreud

Not sure with this car. On others, some are stored until cleared, others until battery reset, and others until the light goes off.

What is your boost gauge doing when it's dropping power? Any pops/smoke/fuel smell when it bogs?

Do you have a tuner where you can datalog and post some logs up?

Would also be nice to see what the fuel pressure is doing.

When you accelerate in other, lower gears, does it still do it if you mildly apply throttle (75%) versus 100% throttle?

04stangman

My boost gauge goes up a little bit, no unual noise that I can tell other than it sounding like something is lagging in the rear end becasue of the loss of power. The more throttle I give the car, the worse it gets and the more the rpms raise excessively. It seems like however, the symtoms get worse on the higher gears.....

I dont have a tuner, I wish I did though.

W1ldcat

Could it be your clutch?

moosestang

Sounds like your clutch is slipping, if boost drops, then maybe your belt is slipping.

Can you smell burnt clutch? The clutch will slip easier in higher gears.

Derf00

Get the code for the check engine light first, see what it says but yes I agree with moosestang, clutch issue.