Poor Acceleration

[TedK]

Opinions please, as to what might be wrong with my car.....

2004 TT, 39,000 miles, new Bosch plugs at 30,000.

Car feels normal around town, no issues, no warning lights.

Short blips at 1/3 throttle feel good and gets to .7 bar. By short I mean 2.5K - 3K rpm, feels like it wants to run, but then...

Full throttle is the problem...3K - 6K rpm boost first hits .5 then decreases to .4 and that majic boosted acceleration is

simply not there and the rpm's climb slowly. All pipes seem connected.

Any opinions appreciated.

Thanks, Ted K

Edited March 3, 2009 by TedK

[Danyol]

How long has this been happening?

Bad gas or Issue with a CAT (although I think this one would throw a code); sounds like timing and boost is being cut back by ECU

[TedK]

Just started driving the car again after it sat for 3 months, I'm on my third tank of Cheveron so I don't think its the gas. Could the BOV's need replacing? No codes, and it does everything well except full throttle.

Ted K

[Loren]

Need to check the DME readout to be sure but it sounds like an air leak or a bad MAF.

Getting the readings would tell for sure which.

[TedK]

Thanks folks, just wanted to run it by the crowd before going the money route.

Ted K

[wross996TT]

As Loren says...get the codes read. My guess is also a leak.

[Chuck Jones]

By "BOV"....are you referring to the diverter valves? If they're bad, you usually get a honking noise and can focus in on them pretty easily. The lack of ummph is usually a leak....did you mess with any of the hose connections to your intercoolers or throttle body?

If it's the MAF, you usually get a check engine light, or the famous PSE/ABS warning lights....mostly after a hard run.

[TedK]

Put the rear up in the air yesterday, pulled the air filter box out and checked the hoses, lines, etc. All looks OK, I guess I will just have the dealer diagnose it. Before I do, I will run her some more to see if I can hear any honking, thanks for the tip.

Ted K

[jackchung]

Put the rear up in the air yesterday, pulled the air filter box out and checked the hoses, lines, etc. All looks OK, I guess I will just have the dealer diagnose it. Before I do, I will run her some more to see if I can hear any honking, thanks for the tip.

Ted K

Check my post, I seem to be having a similar issue. If you find out what is causing it, please let me know! Thank you!

[TedK]

This is embarrasing and frustrating at the same time. Dealer had to drop the engine due to a "hard fault" on a knock sensor. Well, guess what.......while the car was sitting out back during my new garage construction, mice decided to take up residence in the engine compartment and chewed through some wires. Frustrating because if my garage was finished, I could have done this myself as I have a four post lift and the other required tools. Live and learn. I'm supposed to get her back tomorrow after a $2400 mouse fix at the dealer. At least I'm at the point where we are parking on the new slab and not out it the dirt anymore. I need a drink.