New MSP 2003.5 - hesitation question

[Ben@Toeldo]

Hi all,

Long time lurker, first time poster.

I recently picked up a 2003.5 MSP (thanx Bryan) and I noticed that I have a significant hesitation under heavy throttle. Let me try to describe the problem.

Under WOT the car seems to accelerate normally till it hits a brick wall of hesitation. The hesitation is very sudden and violent. If i'm not carful it feels like I could be kissing windshield when this hesitation hits. So far i've had the problem in 2nd and 5th gear.

The hesitation only lasts for a split second. After that the car operates normally.

I did some research on the forums and found that cold weather may be causing some problems with the air sensor. I'm not sure what to think.

The car is stock and seems to be well taken care of...but honestly I have no clue how the previous driver drove the car though.

Any thoughts guys?

 

[Newf]

get the ECU flashed with the latest update if it hasn't . It'll help a little. If it already was there would be a sticker somewhere on the car saying so.

 

[TX Speed Demon]

Sounds more like fuel cut - that's the only violent stopping that occurs. Happens when it's cold out and boost maxes out the MAF sensor. If the temps by you are under 40degrees I'm 99% sure this is what you are experiencing. It happens on stock cars in cold weather and on all cars with enough boost. Solution is a Fuel Cut Defender (although I wouldn't suggest this as Fuel Cut is also there to save your motor from detonation), running less boost in cold weather or easing into the throttle to help lessen the sudden increase in air pressure (spikes) on the MAF.

Hesitation feels more like your car is being held back by a rubber band. It's not sudden at all, just feels like your car isn't going as fast as it should, then suddly in the upper RPMs the A/F ratio thins out and your car has a boost in power. YOu can get around this by getting a Fuel Pressure Reducer, some sort of EMS, or also by rolling into the throttle slower.

 

[Matrix]

I've experience hesitation at the ~4000rpm range also, but not as severe as you describe it. Ever since I got the reflash and my downpipe, this problem is extremely rare.